75 results on '"Knight AK"'
Search Results
2. An epigenetic clock for gestational age at birth based on blood methylation data
- Author
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Knight, AK, Craig, JM, Theda, C, Baekvad-Hansen, M, Bybjerg-Grauholm, J, Hansen, CS, Hollegaard, MV, Hougaard, DM, Mortensen, PB, Weinsheimer, SM, Werge, TM, Brennan, PA, Cubells, JF, Newport, DJ, Stowe, ZN, Cheong, JLY, Dalach, P, Doyle, LW, Loke, YJ, Baccarelli, AA, Just, AC, Wright, RO, Tellez-Rojo, MM, Svensson, K, Trevisi, L, Kennedy, EM, Binder, EB, Iurato, S, Czamara, D, Raikkonen, K, Lahti, JMT, Pesonen, A-K, Kajantie, E, Villa, PM, Laivuori, H, Hamalainen, E, Park, HJ, Bailey, LB, Parets, SE, Kilaru, V, Menon, R, Horvath, S, Bush, NR, LeWinn, KZ, Tylavsky, FA, Conneely, KN, Smith, AK, Knight, AK, Craig, JM, Theda, C, Baekvad-Hansen, M, Bybjerg-Grauholm, J, Hansen, CS, Hollegaard, MV, Hougaard, DM, Mortensen, PB, Weinsheimer, SM, Werge, TM, Brennan, PA, Cubells, JF, Newport, DJ, Stowe, ZN, Cheong, JLY, Dalach, P, Doyle, LW, Loke, YJ, Baccarelli, AA, Just, AC, Wright, RO, Tellez-Rojo, MM, Svensson, K, Trevisi, L, Kennedy, EM, Binder, EB, Iurato, S, Czamara, D, Raikkonen, K, Lahti, JMT, Pesonen, A-K, Kajantie, E, Villa, PM, Laivuori, H, Hamalainen, E, Park, HJ, Bailey, LB, Parets, SE, Kilaru, V, Menon, R, Horvath, S, Bush, NR, LeWinn, KZ, Tylavsky, FA, Conneely, KN, and Smith, AK
- Abstract
BACKGROUND: Gestational age is often used as a proxy for developmental maturity by clinicians and researchers alike. DNA methylation has previously been shown to be associated with age and has been used to accurately estimate chronological age in children and adults. In the current study, we examine whether DNA methylation in cord blood can be used to estimate gestational age at birth. RESULTS: We find that gestational age can be accurately estimated from DNA methylation of neonatal cord blood and blood spot samples. We calculate a DNA methylation gestational age using 148 CpG sites selected through elastic net regression in six training datasets. We evaluate predictive accuracy in nine testing datasets and find that the accuracy of the DNA methylation gestational age is consistent with that of gestational age estimates based on established methods, such as ultrasound. We also find that an increased DNA methylation gestational age relative to clinical gestational age is associated with birthweight independent of gestational age, sex, and ancestry. CONCLUSIONS: DNA methylation can be used to accurately estimate gestational age at or near birth and may provide additional information relevant to developmental stage. Further studies of this predictor are warranted to determine its utility in clinical settings and for research purposes. When clinical estimates are available this measure may increase accuracy in the testing of hypotheses related to developmental age and other early life circumstances.
- Published
- 2016
3. Positioning to reduce the risk of Sudden Infant Death Syndrome (SIDS): current trends and research.
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Knight AK
- Abstract
Supine positioning during sleep for all healthy infants is advocated by the American Academy of Pediatrics Task Force on Infant Positioning and Sudden Infant Death Syndrome (SIDS). This review will summarize published studies related to SIDS positioning recommendations, efficacy of recent public health campaigns to reduce prone sleep positioning and SIDS, and developmental considerations regarding supine sleep positioning for infants. [ABSTRACT FROM AUTHOR]
- Published
- 1998
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4. Poverty and neighborhood opportunity effects on neonate DNAm developmental age.
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Pilkay SR, Knight AK, Bush NR, LeWinn K, Davis RL, Tylavsky F, and Smith AK
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- Humans, Female, Infant, Newborn, Male, Adult, Neighborhood Characteristics, Residence Characteristics, Pregnancy, Fetal Blood metabolism, Income, Gestational Age, Poverty, DNA Methylation
- Abstract
Background: Children from families with low socioeconomic status (SES), as determined by income, experience several negative outcomes, such as higher rates of newborn mortality and behavioral issues. Moreover, associations between DNA methylation and low income or poverty status are evident beginning at birth, suggesting prenatal influences on offspring development. Recent evidence suggests neighborhood opportunities may protect against some of the health consequences of living in low income households. The goal of this study was to assess whether neighborhood opportunities moderate associations between household income (HI) and neonate developmental maturity as measured with DNA methylation., Methods: Umbilical cord blood DNA methylation data was available in 198 mother-neonate pairs from the larger CANDLE cohort. Gestational age acceleration was calculated using an epigenetic clock designed for neonates. Prenatal HI and neighborhood opportunities measured with the Childhood Opportunity Index (COI) were regressed on gestational age acceleration controlling for sex, race, and cellular composition., Results: Higher HI was associated with higher gestational age acceleration (B = .145, t = 4.969, p = 1.56x10-6, 95% CI [.087, .202]). Contrary to expectation, an interaction emerged showing higher neighborhood educational opportunity was associated with lower gestational age acceleration at birth for neonates with mothers living in moderate to high HI (B = -.048, t = -2.08, p = .03, 95% CI [-.092, -.002]). Female neonates showed higher gestational age acceleration at birth compared to males. However, within males, being born into neighborhoods with higher social and economic opportunity was associated with higher gestational age acceleration., Conclusion: Prenatal HI and neighborhood qualities may affect gestational age acceleration at birth. Therefore, policy makers should consider neighborhood qualities as one opportunity to mitigate prenatal developmental effects of HI., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pilkay et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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5. DNA methylation as a window into female reproductive aging.
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Knight AK, Spencer JB, and Smith AK
- Subjects
- Female, Humans, Reproduction genetics, Menopause genetics, Ovary, Epigenesis, Genetic, DNA Methylation, Aging genetics
- Abstract
People with ovaries experience reproductive aging as their reproductive function and system declines. This has significant implications for both fertility and long-term health, with people experiencing an increased risk of cardiometabolic disorders after menopause. Reproductive aging can be assessed through markers of ovarian reserve, response to fertility treatment or molecular biomarkers, including DNA methylation. Changes in DNA methylation with age associate with poorer reproductive outcomes, and epigenome-wide studies can provide insight into genes and pathways involved. DNA methylation-based epigenetic clocks can quantify biological age in reproductive tissues and systemically. This review provides an overview of hallmarks and theories of aging in the context of the reproductive system, and then focuses on studies of DNA methylation in reproductive tissues.
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- 2024
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6. Infant epigenetic aging moderates the link between Black maternal childhood trauma and offspring symptoms of psychopathology.
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McKenna BG, Knight AK, Smith AK, Corwin EJ, Carter SE, Palmer RHC, Dunlop AL, and Brennan PA
- Abstract
Although offspring of women exposed to childhood trauma exhibit elevated rates of psychopathology, many children demonstrate resilience to these intergenerational impacts. Among the variety of factors that likely contribute to resilience, epigenetic processes have been suggested to play an important role. The current study used a prospective design to test the novel hypothesis that offspring epigenetic aging - a measure of methylation differences that are associated with infant health outcomes - moderates the relationship between maternal exposure to childhood adversity and offspring symptomatology. Maternal childhood adversity was self-reported during pregnancy via the ACEs survey and the CTQ, which assessed total childhood trauma as well as maltreatment subtypes (i.e., emotional, physical, and sexual abuse). Offspring blood samples were collected at or shortly after birth and assayed on a DNA methylation microarray, and offspring symptomatology was assessed with the CBCL/1.5-5 when offspring were 2-4 years old. Results indicated that maternal childhood trauma, particularly sexual abuse, was predictive of offspring symptoms ( p s = 0.003-0.03). However, the associations between maternal sexual abuse and offspring symptomatology were significantly attenuated in offspring with accelerated epigenetic aging. These findings further our understanding of how epigenetic processes may contribute to and attenuate the intergenerational link between stress and psychopathology.
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- 2023
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7. Evaluation of pediatric epigenetic clocks across multiple tissues.
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Fang F, Zhou L, Perng W, Marsit CJ, Knight AK, Cardenas A, Aung MT, Hivert MF, Aris IM, Goodrich JM, Smith AK, Gaylord A, Fry RC, Oken E, O'Connor G, Ruden DM, Trasande L, Herbstman JB, Camargo CA Jr, Bush NR, Dunlop AL, Dabelea DM, Karagas MR, Breton CV, Ober C, Everson TM, Page GP, and Ladd-Acosta C
- Subjects
- Pregnancy, Infant, Humans, Child, Female, Epigenomics, Epigenesis, Genetic, Placenta, DNA Methylation
- Abstract
Background: Epigenetic clocks are promising tools for assessing biological age. We assessed the accuracy of pediatric epigenetic clocks in gestational and chronological age determination., Results: Our study used data from seven tissue types on three DNA methylation profiling microarrays and found that the Knight and Bohlin clocks performed similarly for blood cells, while the Lee clock was superior for placental samples. The pediatric-buccal-epigenetic clock performed the best for pediatric buccal samples, while the Horvath clock is recommended for children's blood cell samples. The NeoAge clock stands out for its unique ability to predict post-menstrual age with high correlation with the observed age in infant buccal cell samples., Conclusions: Our findings provide valuable guidance for future research and development of epigenetic clocks in pediatric samples, enabling more accurate assessments of biological age., (© 2023. BioMed Central Ltd., part of Springer Nature.)
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- 2023
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8. Traffic-related air pollution and supplemental folic acid intake in relation to DNA methylation in granulosa cells.
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Gaskins AJ, Hood RB, Ford JB, Hauser R, Knight AK, Smith AK, and Everson TM
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- Humans, Female, Nitrogen Dioxide adverse effects, Nitrogen Dioxide analysis, Aging genetics, Folic Acid adverse effects, DNA Methylation, Air Pollution adverse effects
- Abstract
Background: Higher exposure to traffic-related air pollution (TRAP) is related to lower fertility, with specific adverse effects on the ovary. Folic acid may attenuate these effects. Our goal was to explore the relation of TRAP exposure and supplemental folic acid intake with epigenetic aging and CpG-specific DNA methylation (DNAm) in granulosa cells (GC). Our study included 61 women undergoing ovarian stimulation at a fertility center (2005-2015). DNAm levels were profiled in GC using the Infinium MethylationEPIC BeadChip. TRAP was defined using a spatiotemporal model to estimate residence-based nitrogen dioxide (NO
2 ) exposure. Supplemental folic acid intake was measured with a validated food frequency questionnaire. We used linear regression to evaluate whether NO2 or supplemental folic acid was associated with epigenetic age acceleration according to the Pan-tissue, mural GC, and GrimAge clocks or DNAm across the genome adjusting for potential confounders and accounting for multiple testing with a false discovery rate < 0.1., Results: There were no associations between NO2 or supplemental folic acid intake and epigenetic age acceleration of GC. NO2 and supplemental folic acid were associated with 9 and 11 differentially methylated CpG sites. Among these CpGs, only cg07287107 exhibited a significant interaction (p-value = 0.037). In women with low supplemental folic acid, high NO2 exposure was associated with 1.7% higher DNAm. There was no association between NO2 and DNAm in women with high supplemental folic acid. The genes annotated to the top 250 NO2 -associated CpGs were enriched for carbohydrate and protein metabolism, postsynaptic potential and dendrite development, and membrane components and exocytosis. The genes annotated to the top 250 supplemental folic acid-associated CpGs were enriched for estrous cycle, learning, cognition, synaptic organization and transmission, and size and composition of neuronal cell bodies., Conclusions: We found no associations between NO2 , supplemental folic acid, and DNAm age acceleration of GC. However, there were 20 differentially methylated CpGs and multiple enriched GO terms associated with both exposures suggesting that differences in GC DNAm could be a plausible mechanism underlying the effects of TRAP and supplemental folic acid on ovarian function., (© 2023. The Author(s).)- Published
- 2023
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9. Analysis of Pregnancy Complications and Epigenetic Gestational Age of Newborns.
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Ladd-Acosta C, Vang E, Barrett ES, Bulka CM, Bush NR, Cardenas A, Dabelea D, Dunlop AL, Fry RC, Gao X, Goodrich JM, Herbstman J, Hivert MF, Kahn LG, Karagas MR, Kennedy EM, Knight AK, Mohazzab-Hosseinian S, Morin A, Niu Z, O'Shea TM, Palmore M, Ruden D, Schmidt RJ, Smith AK, Song A, Spindel ER, Trasande L, Volk H, Weisenberger DJ, and Breton CV
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- Pregnancy, Child, Humans, Infant, Newborn, Female, Adolescent, Young Adult, Adult, Middle Aged, Infant, Cohort Studies, Gestational Age, Epigenesis, Genetic, Diabetes, Gestational epidemiology, Pre-Eclampsia, Hypertension, Pregnancy-Induced
- Abstract
Importance: Preeclampsia, gestational hypertension, and gestational diabetes, the most common pregnancy complications, are associated with substantial morbidity and mortality in mothers and children. Little is known about the biological processes that link the occurrence of these pregnancy complications with adverse child outcomes; altered biological aging of the growing fetus up to birth is one molecular pathway of increasing interest., Objective: To evaluate whether exposure to each of these 3 pregnancy complications (gestational diabetes, gestational hypertension, and preeclampsia) is associated with accelerated or decelerated gestational biological age in children at birth., Design, Setting, and Participants: Children included in these analyses were born between 1998 and 2018 and spanned multiple geographic areas of the US. Pregnancy complication information was obtained from maternal self-report and/or medical record data. DNA methylation measures were obtained from blood biospecimens collected from offspring at birth. The study used data from the national Environmental Influences on Child Health Outcomes (ECHO) multisite cohort study collected and recorded as of the August 31, 2021, data lock date. Data analysis was performed from September 2021 to December 2022., Exposures: Three pregnancy conditions were examined: gestational hypertension, preeclampsia, and gestational diabetes., Main Outcomes and Measures: Accelerated or decelerated biological gestational age at birth, estimated using existing epigenetic gestational age clock algorithms., Results: A total of 1801 child participants (880 male [48.9%]; median [range] chronological gestational age at birth, 39 [30-43] weeks) from 12 ECHO cohorts met the analytic inclusion criteria. Reported races included Asian (49 participants [2.7%]), Black (390 participants [21.7%]), White (1026 participants [57.0%]), and other races (92 participants [5.1%]) (ie, American Indian or Alaska Native, Native Hawaiian or other Pacific Islander, multiple races, and other race not specified). In total, 524 participants (29.0%) reported Hispanic ethnicity. Maternal ages ranged from 16 to 45 years of age with a median of 29 in the analytic sample. A range of maternal education levels, from less than high school (260 participants [14.4%]) to Bachelor's degree and above (629 participants [34.9%]), were reported. In adjusted regression models, prenatal exposure to maternal gestational diabetes (β, -0.423; 95% CI, -0.709 to -0.138) and preeclampsia (β, -0.513; 95% CI, -0.857 to -0.170), but not gestational hypertension (β, 0.003; 95% CI, -0.338 to 0.344), were associated with decelerated epigenetic aging among exposed neonates vs those who were unexposed. Modification of these associations, by sex, was observed with exposure to preeclampsia (β, -0.700; 95% CI, -1.189 to -0.210) and gestational diabetes (β, -0.636; 95% CI, -1.070 to -0.200), with associations observed among female but not male participants., Conclusions and Relevance: This US cohort study of neonate biological changes related to exposure to maternal pregnancy conditions found evidence that preeclampsia and gestational diabetes delay biological maturity, especially in female offspring.
- Published
- 2023
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10. Markers of ovarian reserve are associated with reproductive age acceleration in granulosa cells from IVF patients.
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Knight AK, Hipp HS, Abhari S, Gerkowicz SA, Katler QS, McKenzie LJ, Shang W, Smith AK, and Spencer JB
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- Acceleration, Anti-Mullerian Hormone, Cross-Sectional Studies, Female, Fertilization in Vitro, Granulosa Cells, Humans, Ovarian Reserve
- Abstract
Study Question: Is reproductive aging in granulosa cells associated with markers of ovarian reserve?, Summary Answer: Age acceleration was associated with anti-Mullerian hormone (AMH) levels, antral follicle count (AFC), oocyte yield and maturity, and the number of successfully fertilized embryos., What Is Known Already: The rate of reproductive aging varies among women of the same age. DNA methylation can be used to predict epigenetic age in a variety of tissues., Study Design, Size, Duration: This was a cross-sectional study of 70 women at the time of oocyte retrieval., Participants/materials, Setting, Methods: The 70 participants were recruited for this study at an academic medical center and they provided follicular fluid samples at the time of oocyte retrieval. Granulosa cells were isolated and assessed on the MethylationEPIC array. Linear regression was used to evaluate the associations between DNA methylation-based age predictions from granulosa cells and chronological age. Age acceleration was calculated as the residual of regressing DNA methylation-based age on chronological age. Linear regressions were used to determine the associations between age acceleration and markers of ovarian reserve and IVF cycle outcomes., Main Results and the Role of Chance: Participants were a mean of 36.7 ± 3.9 years old. In regards to race, 54% were white, 19% were African American and 27% were of another background. Age acceleration was normally distributed and not associated with chronological age. Age acceleration was negatively associated with AMH levels (t = -3.1, P = 0.003) and AFC (t = -4.0, P = 0.0001), such that women with a higher age acceleration had a lower ovarian reserve. Age acceleration was also negatively correlated with the total number of oocytes retrieved (t = -3.9, P = 0.0002), the number of mature oocytes (t = -3.8, P = 0.0003) and the number of fertilized oocytes or two-pronuclear oocytes (t = -2.8, P = 0.008) in the main analysis., Limitations, Reasons for Caution: This study used pooled follicular fluid, which does not allow for the investigation of individual follicles. Infertility patients may also be different from the general population, but, as we used granulosa cells, the participants had to be from an IVF population., Wider Implications of the Findings: This study demonstrated that epigenetic age and age acceleration can be calculated from granulosa cells collected at the time of oocyte retrieval. GrimAge most strongly predicted chronological age, and GrimAge acceleration was associated with baseline and cycle characteristics as well as cycle outcomes, which indicates its potential clinical relevance in evaluating both oocyte quantity and quality., Study Funding/competing Interest(s): This study was supported by the National Institutes of Health (UL1TR002378) and the Building Interdisciplinary Research Careers in Women's Health Program (K12HD085850) to A.K.K. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The funding source had no role in any aspect of this study. J.B.S. serves as Vice Chair for the American Society for Reproductive Medicine Education Committee, is a Medical Committee Advisor for the Jewish Fertility Foundation and works with Jscreen. J.B.S. has received funding from Georgia Clinical Translational Research Alliance. H.S.H., J.B.S. and A.K.S. have received NIH funding for other projects. A.K.K., S.A.G., S.G., Q.S.K., L.J.M. and W.S. have no conflicts of interest., Trial Registration Number: N/A., (© The Author(s) 2022. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2022
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11. A Case-Control Study of Follicular Fluid Cytokine Profiles in Women with Diminished Ovarian Reserve.
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Abhari S, Lu J, Hipp HS, Petritis B, Gerkowicz SA, Katler QS, Yen HH, Mao Y, Tang H, Shang W, McKenzie LJ, Smith AK, Huang RP, and Knight AK
- Subjects
- Anti-Mullerian Hormone metabolism, Case-Control Studies, Cytokines metabolism, Female, Fertilization in Vitro, Follicular Fluid metabolism, Humans, Male, Ovulation Induction, Ovarian Diseases metabolism, Ovarian Reserve
- Abstract
Ovarian reserve is an important determinant of a woman's reproductive potential, and women with diminished ovarian reserve (DOR) often seek in vitro fertilization (IVF). The underlying etiology of DOR is unknown, but follicular fluid cytokine concentrations likely play a role in follicular development and maturation. The present study seeks to investigate the expression of cytokines in follicular fluid (FF) of women with DOR undergoing IVF and explore correlated functional pathways. One hundred ninety-four women undergoing ovarian stimulation were recruited at the time of oocyte retrieval. Women were classified as having DOR if they met one or more of the following criteria: AMH < 1 ng/ml, FSH > 10 mIU/ml, and/or AFC < 10. Controls included women undergoing IVF for male factor, tubal factor due to tubal ligation, or planned oocyte cryopreservation (non-oncologic). The concentrations of 480 cytokines and related growth factors in follicular fluid were determined using a multiplex immunoassay. Fifty-nine cytokines had significantly different concentrations (53 higher and 6 lower) in the DOR relative to the control group after adjusting for age and body mass index (BMI) (false discovery rate; FDR < 0.1). Using the most informative 44 biomarkers as indicated by a random forest (RF) model, an area under the curve (AUC) of 0.78 was obtained. Thus, follicular microenvironment differs between women with DOR and normal ovarian reserve. The differentially expressed cytokines belong to diverse processes that are primarily involved in follicular maturation and ovulation. These changes may play an important role in treatment outcomes in women with DOR., (© 2021. Society for Reproductive Investigation.)
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- 2022
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12. Advancing understanding of maternal age: correlating epigenetic clocks in blood and myometrium.
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Erickson EN, Knight AK, Smith AK, and Myatt L
- Abstract
Background: Advanced maternal age is currently a term defined by chronological age. However, a group of biomarkers known as epigenetic clocks, which can predict morbidity and mortality, has been used to estimate measures of biological aging. Uterine myometrial function during the process of parturition may be influenced by aging, as labor dystocia, unplanned intrapartum cesarean birth, and postpartum hemorrhage are more common in older individuals. The purpose of this study was to evaluate the use of epigenetic clocks in maternal myometrium and blood for predicting age and to evaluate the correlation of epigenetic age between the tissues., Results: We compared epigenetic age in blood and myometrial samples provided by women undergoing planned cesarean birth at term gestation. Chronological age ranged from 20 to 50 with a median (IQR) age of 35.5(8) years. The MethylationEPIC BeadChip was used to obtain DNA methylation data, and then epigenetic age was calculated using the Horvath, Hannum, GrimAge, and PhenoAge clocks. Spearman correlations of epigenetic age with chronological age were calculated. We tested the relationship of epigenetic age in maternal blood to epigenetic age in myometrium. Age acceleration, for each clock, was also correlated between tissues. Twenty-seven participants provided samples, and 21 matched specimens were included in the final analysis after quality control. Spearman correlation between maternal chronological age and epigenetic age were significant in three of the four clocks (pan-tissue Horvath, Hannum, and GrimAge), for both myometrium and blood samples. Correlations between blood epigenetic age and maternal age ranged from 0.72 to 0.87 (all p < 0.001). Correlations between myometrial epigenetic age and maternal age were also significant (0.62-0.70, p = 0.002), though lower than correlations seen in blood. Maternal blood epigenetic age also correlated with epigenetic age in myometrium with each of these three clocks 0.60 ( p = 0.004, Horvath), 0.63 ( p = 0.003, Hannum), and 0.80 ( p < 0.001, GrimAge). GrimAge age acceleration had the highest correlation between tissues among the clocks (0.49, p = 0.02)., Conclusions: Given the limited sample, this study provides insight into the potential use of epigenetic age derived from blood as a proxy for myometrial epigenetic age, which may be a useful biomarker in estimating myometrial biological age in relationship to myometrial dysfunction. GrimAge outperformed the other tested clocks in terms of concordance of epigenetic age and age acceleration between tissues; however, the Horvath and Hannum clocks may be useful depending on the outcome of interest in pregnancy., Competing Interests: Competing interests The authors declare that they have no competing interests.
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- 2022
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13. Vaginal Microbiome Composition in Early Pregnancy and Risk of Spontaneous Preterm and Early Term Birth Among African American Women.
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Dunlop AL, Satten GA, Hu YJ, Knight AK, Hill CC, Wright ML, Smith AK, Read TD, Pearce BD, and Corwin EJ
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- Actinobacteria, Black or African American, Female, Humans, Infant, Newborn, Pregnancy, Prevotella, RNA, Ribosomal, 16S, Term Birth, Vagina, Microbiota, Premature Birth
- Abstract
Objective: To evaluate the association between the early pregnancy vaginal microbiome and spontaneous preterm birth (sPTB) and early term birth (sETB) among African American women., Methods: Vaginal samples collected in early pregnancy (8-14 weeks' gestation) from 436 women enrolled in the Emory University African American Vaginal, Oral, and Gut Microbiome in Pregnancy Study underwent 16S rRNA gene sequencing of the V3-V4 region, taxonomic classification, and community state type (CST) assignment. We compared vaginal CST and abundance of taxa for women whose pregnancy ended in sPTB (N = 44) or sETB (N= 84) to those who delivered full term (N = 231)., Results: Nearly half of the women had a vaginal microbiome classified as CST IV (Diverse CST), while one-third had CST III ( L. iners dominated) and just 16% had CST I, II, or V (non-iners Lactobacillus dominated). Compared to vaginal CST I, II, or V (non-iners Lactobacillus dominated), both CST III ( L. iners dominated) and CST IV (Diverse) were associated with sPTB with an adjusted odds ratio (95% confidence interval) of 4.1 (1.1, infinity) and 7.7 (2.2, infinity), respectively, in multivariate logistic regression. In contrast, no vaginal CST was associated with sETB. The linear decomposition model (LDM) based on amplicon sequence variant (ASV) relative abundance found a significant overall effect of the vaginal microbiome on sPTB (p=0.034) but not sETB (p=0.320), whereas the LDM based on presence/absence of ASV found no overall effect on sPTB (p=0.328) but a significant effect on sETB (p=0.030). In testing for ASV-specific effects, the LDM found that no ASV was significantly associated with sPTB considering either relative abundance or presence/absence data after controlling for multiple comparisons (FDR 10%), although in marginal analysis the relative abundance of Gardnerella vaginalis (p=0.011), non-iners Lactobacillus (p=0.016), and Mobiluncus curtisii (p=0.035) and the presence of Atopobium vaginae (p=0.049), BVAB2 (p=0.024), Dialister microaerophilis (p=0.011), and Prevotella amnii (p=0.044) were associated with sPTB. The LDM identified the higher abundance of 7 ASVs and the presence of 13 ASVs, all commonly residents of the gut, as associated with sETB at FDR < 10%., Conclusions: In this cohort of African American women, an early pregnancy vaginal CST III or IV was associated with an increased risk of sPTB but not sETB. The relative abundance and presence of distinct taxa within the early pregnancy vaginal microbiome was associated with either sPTB or sETB., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Dunlop, Satten, Hu, Knight, Hill, Wright, Smith, Read, Pearce and Corwin.)
- Published
- 2021
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14. Epigenetic prediction of 17β-estradiol and relationship to trauma-related outcomes in women.
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Hack LM, Nishitani S, Knight AK, Kilaru V, Maddox SA, Seligowski AV, Jovanovic T, Ressler KJ, Smith AK, and Michopoulos V
- Abstract
17β-estradiol (E2) levels in women correlate with multiple neuropsychiatric symptoms, including those that are stress-related. Furthermore, prior work from our group has demonstrated that E2 status influences DNA methylation (DNAm) across the genome. We developed and validated a DNAm-based predictor of E2 (one of four naturally occurring estrogens) using a training set of 183 females and a test set of 79 females from the same traumatized cohort. We showed that predicted E2 levels were highly correlated with measured E2 concentrations in our testing set (r = 0.75, p = 1.8e-15). We further demonstrated that predicted E2 concentrations, in combination with measured values, negatively correlated with current post-traumatic stress disorder (PTSD) (β = -0.38, p = 0.01) and major depressive disorder (MDD) diagnoses (β = -0.45, p = 0.02), as well as a continuous measure of PTSD symptom severity (β = -2.3, p = 0.007) in females. Finally, we tested our predictor in an independent data set (n = 85) also comprised of recently traumatized female subjects to determine if the predictor would generalize to a different population than the one on which it was developed. We found that the correlation between predicted and actual E2 concentrations in the external validation data set was also high (r = 0.48, p = 3.0e-6). While further validation is warranted, a DNAm predictor of E2 concentrations will advance our understanding of hormone-epigenetic interactions. Furthermore, such a DNAm predictor may serve as an epigenetic proxy for E2 concentrations and thus provide an important biomarker to better evaluate the contribution of E2 to current and potentially future psychiatric symptoms in samples for which E2 is not measured., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)
- Published
- 2021
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15. Maternal prenatal depression and epigenetic age deceleration: testing potentially confounding effects of prenatal stress and SSRI use.
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McKenna BG, Hendrix CL, Brennan PA, Smith AK, Stowe ZN, Newport DJ, and Knight AK
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- DNA Methylation, Deceleration, Depression, Epigenesis, Genetic, Female, Humans, Infant, Newborn, Pregnancy, Selective Serotonin Reuptake Inhibitors, Pregnancy Complications, Prenatal Exposure Delayed Effects
- Abstract
Previous studies suggest epigenetic alterations may contribute to the association between maternal prenatal depression and adverse offspring outcomes. Developmental researchers have recently begun to examine these associations in relation to epigenetic age acceleration/deceleration, a biomarker of developmental risk that reflects the deviation between epigenetic age and chronological age. In the perinatal period, preliminary studies indicate that maternal prenatal depression may lead to epigenetic age deceleration in newborns, which may predict adverse developmental outcomes. The present study examined the relationship between maternal prenatal exposures (i.e., depression, stress, and SSRI use) and offspring epigenetic age deceleration in 303 mother-offspring dyads. Women were recruited in the first trimester of pregnancy and followed longitudinally until delivery. Maternal depression, perceived stress, and SSRI use were assessed at each prenatal visit. Newborn epigenetic age was determined via cord blood samples. Results indicated maternal prenatal stress was not associated with newborn epigenetic age deceleration (ΔR
2 = 0.002; p = 0.37). Maternal prenatal depression was associated with decelerated epigenetic age (ΔR2 = 0.01, p = 0.04), but this relationship did not hold when accounting for maternal use of SSRIs (ΔR2 = 0.002, p = 0.43). Conversely, maternal SSRI use significantly predicted newborn epigenetic age deceleration over and above the influence of maternal depression (ΔR2 = 0.03, p = 0.001). These findings suggest maternal prenatal SSRI use may significantly contribute to the previously documented association between maternal prenatal depression and epigenetic age deceleration. Further studies are needed to examine how these epigenetic differences at birth may contribute to adverse outcomes in later development.- Published
- 2021
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16. Explaining the unexplained: new genetic mutations in unexplained premature ovarian insufficiency.
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Knight AK
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- 2020
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17. Transcription factor AP2A affects sFLT1 expression and decidualization in decidual stromal cells: Implications to preeclampsia pathology.
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Manley CN, Deepak V, Ravikumar N, Smith AK, Knight AK, Badell ML, Sidell N, and Rajakumar A
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- Adult, Case-Control Studies, Female, Gene Expression Regulation, Humans, Pre-Eclampsia physiopathology, Pregnancy, Transcription Factor AP-2 metabolism, Transcription Factors, Vascular Endothelial Growth Factor Receptor-1 metabolism, Decidua metabolism, Pre-Eclampsia genetics, Stromal Cells metabolism
- Abstract
Preeclampsia (PE) yields a spectrum of phenotypic expression, leading to varying degrees of hypertension, maternal renal dysfunction and placental insufficiency with resultant maternal and neonatal morbidity. Increased sFLT1 expression contributing to angiogenic factor imbalance, placental hypoxia, failed immune adaptation to the fetus and defective decidualization are among the commonly proposed theories of PE pathogenesis. Recently researchers have focused their attention on the events that occur at the maternal fetal interface as potential contributors to PE pathogenesis. Decidual stromal cells (DSC) isolated from preeclamptic women show diminished ability to decidualize upon stimulation and reduced capacity to downregulate sFlt-1 levels. In this study, we sought to gain insight into the molecular mechanism(s) involved in the aberrant decidualization capacity of PE DSC. Our findings using qRT-PCR show that PE DSCs have 6-fold higher basal levels of transcription factor AP2A (TFAP2A) RNA compared to women without PE and that expression of TFAP2A increases during decidualization but only in DSCs of normotensive (NT) women. Silencing of TFAP2A using Trilencer siRNA upregulated sFLT1 expression only in NT-DSCs but suppressed the expression of decidualization markers PRL, IGFBP1 and their regulator FOXO1 in cells from both groups. Collectively, our observations suggest that TFAP2A acts as a repressor of sFLT1 and plays a necessary role in decidualization possibly through interacting with another factor that is aberrantly expressed in PE DSCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)
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- 2020
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18. Variant interpretation is a component of clinical practice among genetic counselors in multiple specialties.
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Wain KE, Azzariti DR, Goldstein JL, Johnson AK, Krautscheid P, Lepore B, O'Daniel JM, Ritter D, Savatt JM, Riggs ER, and Martin CL
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- Counseling, Female, Genetic Counseling, Humans, Pregnancy, Surveys and Questionnaires, Counselors, Medicine
- Abstract
Purpose: Genomic testing is routinely utilized across clinical settings and can have significant variant interpretation challenges. The extent of genetic counselor (GC) engagement in variant interpretation in clinical practice is unknown. This study aimed to explore clinical GCs' variant interpretation practice across specialties, understand outcomes of this practice, and identify resource and educational needs., Methods: An online survey was administered to National Society of Genetic Counselors members providing clinical counseling., Results: Respondents (n = 239) represented all major clinical specialties. The majority (68%) reported reviewing evidence documented by the laboratory for most (>60%) variants reported; 45.5% report seeking additional evidence. Prenatal GCs were less likely to independently assess reported evidence. Most respondents (67%) report having reached a different conclusion about a variant's classification than the testing laboratory, though infrequently. Time was the most commonly reported barrier (72%) to performing variant interpretation, though the majority (97%) indicated that this practice had an important impact on patient care. When presented with three hypothetical scenarios, evidence typically used for variant interpretation was generally applied correctly., Conclusion: This study is the first to document variant interpretation practice broadly across clinical GC specialties. Our results suggest that variant interpretation should be considered a practice-based competency for GCs.
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- 2020
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19. DNA methylation biomarkers prospectively predict both antenatal and postpartum depression.
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Payne JL, Osborne LM, Cox O, Kelly J, Meilman S, Jones I, Grenier W, Clark K, Ross E, McGinn R, Wadhwa PD, Entringer S, Dunlop AL, Knight AK, Smith AK, Buss C, and Kaminsky ZA
- Subjects
- Adult, Cohort Studies, DNA-Binding Proteins, Depression, Postpartum genetics, Female, Genetic Markers genetics, Humans, Infant, Newborn, Nerve Tissue Proteins blood, Nerve Tissue Proteins genetics, Nuclear Proteins blood, Nuclear Proteins genetics, Predictive Value of Tests, Pregnancy, Prenatal Diagnosis methods, Prospective Studies, DNA Methylation physiology, Depression, Postpartum blood, Depression, Postpartum diagnosis, Prenatal Diagnosis standards, Psychiatric Status Rating Scales standards
- Abstract
We sought to replicate and expand upon previous work demonstrating antenatal TTC9B and HP1BP3 gene DNA methylation is prospectively predictive of postpartum depression (PPD) with ~80% accuracy. In a preterm birth study from Emory, Illumina MethylEPIC microarray derived 1st but not 3rd trimester biomarker models predicted 3rd trimester Edinburgh Postnatal Depression Scale (EPDS) scores ≥ 13 with an AUC=0.8 (95% CI: 0.63-0.8). Bisulfite pyrosequencing derived biomarker methylation was generated using bisulfite pyrosequencing across all trimesters in a pregnancy cohort at UC Irvine and in 3rd trimester from an independent Johns Hopkins pregnancy cohort. A support vector machine model incorporating 3rd trimester EPDS scores, TTC9B, and HP1BP3 methylation status predicted 4 week to 6 week postpartum EPDS ≥ 13 from 3rd trimester blood in the UC Irvine cohort (AUC=0.78, 95% CI: 0.64-0.78) and from the Johns Hopkins cohort (AUC=0.84, 95% CI: 0.72-0.97), both independent of previous psychiatric diagnosis. Technical replicate predictions in a subset of the Johns Hopkins cohort exhibited strong cross experiment correlation. This study confirms the PPD prediction model has the potential to be developed into a clinical tool enabling the identification of pregnant women at future risk of PPD who may benefit from clinical intervention., Competing Interests: Conflict of Interest Z.K. and J.P. are listed as investors on a patent to use the above biomarkers to predict postpartum depression. Z.K. is the founder of and holds equity in METHYX LLC. He also serves as the company's Managing Member. METHYX LLC intends to license technology used in the study that is described in this publication. This arrangement has been reviewed and approved by the Johns Hopkins University in accordance with its conflict of interest policies. J.P. received legal consulting fees from Astra Zeneca, Eli Lilly, Johnson & Johnson, and Abbott Pharmaceuticals and received research support from the NIMH, the Stanley Medical Research Foundation, and SAGE Therapeutics. No additional conflicts of interest are noted., (Copyright © 2019. Published by Elsevier B.V.)
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- 2020
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20. Critical evaluation of copy number variant calling methods using DNA methylation.
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Kilaru V, Knight AK, Katrinli S, Cobb D, Lori A, Gillespie CF, Maihofer AX, Nievergelt CM, Dunlop AL, Conneely KN, and Smith AK
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- Adult, Cohort Studies, Female, Genotype, Humans, Reproducibility of Results, DNA Copy Number Variations genetics, DNA Methylation genetics
- Abstract
Recent technological and methodological developments have enabled the use of array-based DNA methylation data to call copy number variants (CNVs). ChAMP, Conumee, and cnAnalysis450k are popular methods currently used to call CNVs using methylation data. However, so far, no studies have analyzed the reliability of these methods using real samples. Data from a cohort of individuals with genotype and DNA methylation data generated using the HumanMethylation450 and MethylationEPIC BeadChips were used to assess the consistency between the CNV calls generated by methylation and genotype data. We also took advantage of repeated measures of methylation data collected from the same individuals to compare the reliability of CNVs called by ChAMP, Conumee, and cnAnalysis450k for both the methylation arrays. ChAMP identified more CNVs than Conumee and cnAnalysis450k for both the arrays and, as a consequence, had a higher overlap (~62%) with the calls from the genotype data. However, all methods had relatively low reliability. For the MethylationEPIC array, Conumee had the highest reliability (57.6%), whereas for the HumanMethylation450 array, cnAnalysis450k had the highest reliability (43.0%). Overall, the MethylationEPIC array provided significant gains in reliability for CNV calling over the HumanMethylation450 array but not for overlap with CNVs called using genotype data., (© 2019 Wiley Periodicals, Inc.)
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- 2020
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21. Correction: Adapting ACMG/AMP sequence variant classification guidelines for single-gene copy-number variants.
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Brandt T, Sack LM, Arjona D, Tan D, Mei H, Cui H, Gao H, Bean LJH, Ankala A, Del Gaudio D, Johnson AK, Vincent LM, Reavey C, Lai A, Richard G, and Meck JM
- Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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- 2020
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22. Endometriosis, endocrine disrupters, and epigenetics: an investigation into the complex interplay in women with polybrominated biphenyl exposure and endometriosis.
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Gerkowicz SA, Curtis SW, Knight AK, Cobb DO, Spencer JB, Conneely KN, Terrell ML, Marcus M, and Smith AK
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- CpG Islands genetics, DNA Methylation genetics, Endometriosis chemically induced, Endometriosis epidemiology, Endometriosis pathology, Environmental Exposure, Female, Humans, Middle Aged, Polybrominated Biphenyls toxicity, Reproduction drug effects, DNA Methylation drug effects, Endocrine Disruptors toxicity, Endometriosis genetics, Epigenomics
- Abstract
Purpose: Endocrine disrupting compounds (EDCs) have been shown to affect multiple biologic processes especially steroid-hormone processes. We sought to determine differences in DNA methylation exists between women with and without endometriosis following exposure to polybrominated biphenyl (PBB)., Methods: Cross-sectional study of 305 females in the Michigan PBB Registry. DNA was extracted, and DNA methylation was interrogated using the MethylationEPIC BeadChip (Illumina, San Diego, California). Demographic data was analyzed using Chi-squared and T tests. Linear regressions were performed for each cytosine-guanine dinucleotide (CpG) site, modeling the logit transformation of the β value as a linear function of the presence of endometriosis. Sensitivity analyses were conducted controlling for estradiol levels and menopausal status. Replication study performed evaluating for any association between CpGs reported in the literature and our findings., Results: In total, 39,877 CpGs nominally associated with endometriosis (p < 0.05) after adjusting for age and cellular heterogeneity, although none remained significant after correction for multiple comparisons (FDR < 0.05). Pathway analysis of these CpGs showed enrichment in 68 biologic pathways involved in various endocrine, immunologic, oncologic, and cell regulation processes as well as embryologic reproductive tract development and function (FoxO, Wnt, and Hedgehog signaling). We identified 42,261 CpG sites in the literature reported to be associated with endometriosis; 2012 of these CpG sites were also significant in our cohort., Conclusion: We found 39,877 CpG sites that nominally associated with endometriosis (p < 0.05) after adjusting for age and cellular heterogeneity; however, none remained significant after correction for multiple comparisons (FDR < 0.05).
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- 2020
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23. Stability of the vaginal, oral, and gut microbiota across pregnancy among African American women: the effect of socioeconomic status and antibiotic exposure.
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Dunlop AL, Knight AK, Satten GA, Cutler AJ, Wright ML, Mitchell RM, Read TD, Mulle J, Hertzberg VS, Hill CC, Smith AK, and Corwin EJ
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Objective: A growing body of research has investigated the human microbiota and pregnancy outcomes, especially preterm birth. Most studies of the prenatal microbiota have focused on the vagina, with fewer investigating other body sites during pregnancy. Although pregnancy involves profound hormonal, immunological and metabolic changes, few studies have investigated either shifts in microbiota composition across pregnancy at different body sites or variation in composition at any site that may be explained by maternal characteristics. The purpose of this study was to investigate: (1) the stability of the vaginal, oral, and gut microbiota from early (8-14 weeks) through later (24-30 weeks) pregnancy among African American women according to measures of socioeconomic status, accounting for prenatal antibiotic use; (2) whether measures of socioeconomic status are associated with changes in microbiota composition over pregnancy; and (3) whether exposure to prenatal antibiotics mediate any observed associations between measures of socioeconomic status and stability of the vaginal, oral, and gut microbiota across pregnancy., Methods: We used paired vaginal, oral, or gut samples available for 16S rRNA gene sequencing from two time points in pregnancy (8-14 and 24-30 weeks) to compare within-woman changes in measures of alpha diversity (Shannon and Chao1) and beta-diversity (Bray-Curtis dissimilarity) among pregnant African American women ( n = 110). Multivariable linear regression was used to examine the effect of level of education and prenatal health insurance as explanatory variables for changes in diversity, considering antibiotic exposure as a mediator, adjusting for age, obstetrical history, and weeks between sampling., Results: For the oral and gut microbiota, there were no significant associations between measures of socioeconomic status or prenatal antibiotic use and change in Shannon or Chao1 diversity. For the vaginal microbiota, low level of education (high school or less) was associated with an increase in Shannon and Chao1 diversity over pregnancy, with minimal attenuation when controlling for prenatal antibiotic use. Conversely, for within-woman Bray-Curtis dissimilarity for early compared to later pregnancy, low level of education and prenatal antibiotics were associated with greater dissimilarity for the oral and gut sites, with minimal attenuation when controlling for prenatal antibiotics, and no difference in dissimilarity for the vaginal site., Conclusions: Measures of maternal socioeconomic status are variably associated with changes in diversity across pregnancy for the vaginal, oral, and gut microbiota, with minimal attenuation by prenatal antibiotic exposure. Studies that evaluate stability of the microbiota across pregnancy in association with health outcomes themselves associated with socioeconomic status (such as preterm birth) should incorporate measures of socioeconomic status to avoid finding spurious relationships., Competing Interests: Timothy Read is an Academic Editor for PeerJ. The other authors declare that they have no competing interests., (©2019 Dunlop et al.)
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- 2019
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24. Characterizing the Subgingival Microbiome of Pregnant African American Women.
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Yang I, Knight AK, Dunlop AL, and Corwin EJ
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Objective: To generate preliminary data about the subgingival microbiome of pregnant African American women to calculate power for a future larger study and to explore associations among the microbiome, periodontal inflammation, and preterm birth., Design: Comparative descriptive pilot study design., Setting: Urban area in the southeastern United States., Participants: Thirty-four African American women in the third trimester of pregnancy., Methods: Based on visual assessment, participants were placed in two groups: healthy gingiva and gingivitis. Saliva samples were analyzed for interleukin-1β (IL-1β), matrix metalloproteinase-8 (MMP-8), and C-reactive protein (CRP). DNA was extracted from subgingival plaque samples, and amplicons of the fourth hypervariable region were sequenced., Results: We found no differences in overall microbiome diversity between the healthy gingiva (n = 22) and the gingivitis (n = 12) groups although significant differences were found among the bacterial taxa present. The gingivitis group had greater levels of salivary IL-1β and MMP-8, whereas CRP was not different between groups. Overall microbiome diversity was positively associated with the CRP level. We found no significant relationships among the subgingival microbiome, periodontal inflammation, and preterm birth., Conclusion: Gingivitis in pregnancy did not appear to shift the overall composition or diversity of the subgingival microbiome although differences in several bacterial taxa suggest that inflamed gingiva in pregnant women are associated with a disruption in the stability of the subgingival microbiome. A correlation between the abundance of bacteria and CRP also suggests an association between the microbiome and systemic inflammation. These findings provide support for future research about how the oral microbiome and progression of periodontal disease in pregnant women link with adverse pregnancy outcomes., (Copyright © 2019 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.)
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- 2019
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25. Targeted exome analysis identifies the genetic basis of disease in over 50% of patients with a wide range of ataxia-related phenotypes.
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Sun M, Johnson AK, Nelakuditi V, Guidugli L, Fischer D, Arndt K, Ma L, Sandford E, Shakkottai V, Boycott K, Warman-Chardon J, Li Z, Del Gaudio D, Burmeister M, Gomez CM, Waggoner DJ, and Das S
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Ataxia classification, Ataxia diagnosis, Ataxia pathology, Canada, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Mutation genetics, Phenotype, Sequence Analysis, DNA, Young Adult, Ataxia genetics, Exome genetics, Genetic Predisposition to Disease, Exome Sequencing
- Abstract
Purpose: To examine the impact of a targeted exome approach for the molecular diagnosis of patients nationwide with a wide range of ataxia-related phenotypes., Methods: One hundred and seventy patients with ataxia of unknown etiology referred from clinics throughout the United States and Canada were studied using a targeted exome approach. Patients ranged in age from 2 to 88 years. Analysis was focused on 441 curated genes associated with ataxia and ataxia-like conditions., Results: Pathogenic and suspected diagnostic variants were identified in 88 of the 170 patients, providing a positive molecular diagnostic rate of 52%. Forty-six different genes were implicated, with the six most commonly mutated genes being SPG7, SYNE1, ADCK3, CACNA1A, ATP1A3, and SPTBN2, which accounted for >40% of the positive cases. In many cases a diagnosis was provided for conditions that were not suspected and resulted in the broadening of the clinical spectrum of several conditions., Conclusion: Exome sequencing with targeted analysis provides a high-yield approach for the genetic diagnosis of ataxia-related conditions. This is the largest targeted exome study performed to date in patients with ataxia and ataxia-like conditions and represents patients with a wide range of ataxia phenotypes typically encountered in neurology and genetics clinics.
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- 2019
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26. Association between one-carbon metabolism indices and DNA methylation status in maternal and cord blood.
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Knight AK, Park HJ, Hausman DB, Fleming JM, Bland VL, Rosa G, Kennedy EM, Caudill MA, Malysheva O, Kauwell GPA, Sokolow A, Fisher S, Smith AK, and Bailey LB
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- Adult, CpG Islands genetics, Female, Humans, Metabolome, Pregnancy, Sarcosine analogs & derivatives, Sarcosine blood, Young Adult, Carbon metabolism, DNA Methylation genetics, Fetal Blood metabolism
- Abstract
One-carbon metabolism is essential for multiple cellular processes and can be assessed by the concentration of folate metabolites in the blood. One-carbon metabolites serve as methyl donors that are required for epigenetic regulation. Deficiencies in these metabolites are associated with a variety of poor health outcomes, including adverse pregnancy complications. DNA methylation is known to vary with one-carbon metabolite concentration, and therefore may modulate the risk of adverse pregnancy outcomes. This study addresses changes in one-carbon indices over pregnancy and the relationship between maternal and child DNA methylation and metabolite concentrations by leveraging data from 24 mother-infant dyads. Five of the 13 metabolites measured from maternal blood and methylation levels of 993 CpG sites changed over the course of pregnancy. In dyads, maternal and fetal one-carbon concentrations were highly correlated, both early in pregnancy and at delivery. The 993 CpG sites whose methylation levels changed over pregnancy in maternal blood were also investigated for associations with metabolite concentrations in infant blood at delivery, where five CpG sites were associated with the concentration of at least one metabolite. Identification of CpG sites that change over pregnancy may result in better characterization of genes and pathways involved in maintaining a healthy, term pregnancy.
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- 2018
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27. Characterization of gene expression changes over healthy term pregnancies.
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Knight AK, Dunlop AL, Kilaru V, Cobb D, Corwin EJ, Conneely KN, and Smith AK
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- Adult, Black or African American genetics, Female, Gene Expression Regulation, Developmental, Gene Regulatory Networks, Gestational Age, Humans, Pregnancy, Young Adult, Gene Expression Profiling methods, Pregnancy Trimester, First genetics, Pregnancy Trimester, Third genetics, Sequence Analysis, RNA methods, Term Birth genetics
- Abstract
During pregnancy, women experience numerous physiological changes but, to date, there is limited published data that characterize accompanying changes in gene expression over pregnancy. This study sought to characterize the complexity of the transcriptome over the course of pregnancy among women with healthy pregnancies. Subjects provided a venous blood sample during early (6-15 weeks) and late (22-33 weeks) pregnancy, which was used to isolate peripheral blood mononuclear cells prior to RNA extraction. Gene expression was examined for 63 women with uncomplicated, term deliveries. We evaluated the association between weeks gestation at sample collection and expression of each transcript. Of the 16,311 transcripts evaluated, 439 changed over pregnancy after a Bonferroni correction to account for multiple comparisons. Genes whose expression increased over pregnancy were associated with oxygen transport, the immune system, and host response to bacteria. Characterization of changes in the transcriptome over the course of healthy term pregnancies may enable the identification of genes whose expression predicts complications or adverse outcomes of pregnancy., Competing Interests: The authors have declared that no competing interests exist.
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- 2018
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28. Relationship between Epigenetic Maturity and Respiratory Morbidity in Preterm Infants.
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Knight AK, Smith AK, Conneely KN, Dalach P, Loke YJ, Cheong JL, Davis PG, Craig JM, Doyle LW, and Theda C
- Subjects
- Age Factors, Female, Gestational Age, Glucocorticoids therapeutic use, Humans, Infant, Extremely Premature, Infant, Newborn, Infant, Premature, Male, Pulmonary Surfactants therapeutic use, Respiration, Artificial, Victoria, Bronchopulmonary Dysplasia epidemiology, Child Development physiology, Epigenesis, Genetic physiology
- Abstract
Objective: To assess associations between epigenetic maturity of extremely preterm babies (born at less than 28 weeks of gestation), neonatal interventions, and respiratory outcomes, including the administration of surfactant and postnatal corticosteroids, duration of assisted ventilation, and development of bronchopulmonary dysplasia (BPD)., Study Design: DNA was extracted from neonatal blood spots collected after birth from 143 extremely preterm infants born 1991-1992 in Victoria, Australia and used to determined DNA methylation (DNAm). A DNAm based gestational age was determined using our previously published method. The residual of DNAm gestational age and clinically estimated gestational age (referred to as "gestational age acceleration") was used as a measure to assess developmental maturity. Associations between gestational age acceleration and respiratory interventions and morbidities were determined., Results: Infants with higher gestational age acceleration were less likely to receive surfactant (P = .009) or postnatal corticosteroids (P = .008), had fewer days of assisted ventilation (P = .01), and had less BPD (P = .02). Respiratory measures are known to correlate with gestational age; however, models comparing each with clinically estimated gestational age were improved by the addition of the gestational age acceleration measure in the model., Conclusions: Gestational age acceleration correlates with respiratory interventions and outcomes of extremely preterm babies. Surfactant and postnatal corticosteroid use, assisted ventilation days, and BPD rates were all lower in babies who were epigenetically more mature than their obstetrically estimated gestational age. This suggests that gestational age acceleration is a clinically relevant metric of developmental maturity., (Copyright © 2018 Elsevier Inc. All rights reserved.)
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- 2018
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29. The Epigenetic Clock at Birth: Associations With Maternal Antenatal Depression and Child Psychiatric Problems.
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Suarez A, Lahti J, Czamara D, Lahti-Pulkkinen M, Knight AK, Girchenko P, Hämäläinen E, Kajantie E, Lipsanen J, Laivuori H, Villa PM, Reynolds RM, Smith AK, Binder EB, and Räikkönen K
- Subjects
- Adult, Child, Preschool, DNA Methylation, Depressive Disorder psychology, Female, Fetal Blood, Gestational Age, Humans, Male, Pregnancy, Sex Factors, Depressive Disorder diagnosis, Epigenesis, Genetic, Mothers psychology, Pregnancy Complications psychology, Prenatal Exposure Delayed Effects psychology
- Abstract
Objective: Maternal antenatal depression may compromise the fetal developmental milieu and contribute to individual differences in aging and disease trajectories in later life. We evaluated the association between maternal antenatal depression and a novel biomarker of aging at birth, namely epigenetic gestational age (GA) based on fetal cord blood methylation data. We also examined whether this biomarker prospectively predicts and mediates maternal effects on early childhood psychiatric problems., Method: A total of 694 mothers from the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) Study provided information on history of depression diagnosed before pregnancy; 581 completed the Center for Epidemiological Studies Depression Scale throughout pregnancy, and 407 completed the Child Behavior Checklist at child's age 3.7 years (SD = 0.75 year). DNA methylation (DNAm) GA of fetal cord blood DNA was based on the methylation profile of 148 selected cytosine linked to guanine by phosphate (CpG) sites. Epigenetic GA was calculated as the arithmetic difference between DNAm GA and chronological GA and adjusted for chronological GA., Results: Maternal history of depression diagnosed before pregnancy (mean difference = -0.25 SD units, 95% CI = -0.46 to -0.03) and greater antenatal depressive symptoms (-0.08 SD unit per 1-SD unit increase, 95% CI = -0.16 to -0.004) were associated with child's lower epigenetic GA. Child's lower epigenetic GA, in turn, prospectively predicted total and internalizing problems and partially mediated the effects of maternal antenatal depression on internalizing problems in boys., Conclusion: Maternal antenatal depression is associated with lower epigenetic GA in offspring. This lower epigenetic GA seems to be associated with a developmental disadvantage for boys, who, in early childhood, show greater psychiatric problems., (Copyright © 2018 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.)
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- 2018
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30. SLC9B1 methylation predicts fetal intolerance of labor.
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Knight AK, Conneely KN, Kilaru V, Cobb D, Payne JL, Meilman S, Corwin EJ, Kaminsky ZA, Dunlop AL, and Smith AK
- Subjects
- Adolescent, Adult, CpG Islands, Female, Fetal Distress genetics, Gene Expression Profiling, Gestational Age, Humans, Pregnancy, Prenatal Care, Sodium-Hydrogen Exchangers blood, Cesarean Section, DNA Methylation, Pregnancy Trimester, Third genetics, Sodium-Hydrogen Exchangers genetics
- Abstract
Fetal intolerance of labor is a common indication for delivery by Caesarean section. Diagnosis is based on the presence of category III fetal heart rate tracing, which is an abnormal heart tracing associated with increased likelihood of fetal hypoxia and metabolic acidemia. This study analyzed data from 177 unique women who, during their prenatal visits (7-15 weeks and/or 24-32 weeks) to Atlanta area prenatal care clinics, consented to provide blood samples for DNA methylation (HumanMethylation450 BeadChip) and gene expression (Human HT-12 v4 Expression BeadChip) analyses. We focused on 57 women aged 18-36 (mean 25.4), who had DNA methylation data available from their second prenatal visit. DNA methylation patterns at CpG sites across the genome were interrogated for associations with fetal intolerance of labor. Four CpG sites (P value <8.9 × 10
-9 , FDR <0.05) in gene SLC9B1, a Na+ /H+ exchanger, were associated with fetal intolerance of labor. DNA methylation and gene expression were negatively associated when examined longitudinally during pregnancy using a linear mixed-effects model. Positive predictive values of methylation of these four sites ranged from 0.80 to 0.89, while negative predictive values ranged from 0.91 to 0.92. The four CpG sites were also associated with fetal intolerance of labor in an independent cohort (the Johns Hopkins Prospective PPD cohort). Therefore, fetal intolerance of labor could be accurately predicted from maternal blood samples obtained between 24-32 weeks gestation. Fetal intolerance of labor may be accurately predicted from maternal blood samples obtained between 24-32 weeks gestation by assessing DNA methylation patterns of SLC9B1. The identification of pregnant women at elevated risk for fetal intolerance of labor may allow for the development of targeted treatments or management plans.- Published
- 2018
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31. Exposure to Violence Accelerates Epigenetic Aging in Children.
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Jovanovic T, Vance LA, Cross D, Knight AK, Kilaru V, Michopoulos V, Klengel T, and Smith AK
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- Adolescent, Child, DNA chemistry, DNA isolation & purification, DNA Methylation, Female, Heart Rate, Humans, Longitudinal Studies, Male, Saliva chemistry, Aging pathology, Epigenesis, Genetic, Exposure to Violence
- Abstract
Epigenetic processes, including DNA methylation, change reliably with age across the lifespan, such that DNA methylation can be used as an "epigenetic clock". This epigenetic clock can be used to predict age and age acceleration, which occurs when methylation-based prediction of age exceeds chronological age and has been associated with increased mortality. In the current study we examined epigenetic age acceleration using saliva samples collected from children between ages 6-13 (N = 101). Children's exposure to neighborhood violence and heart rate during a stressful task were assessed. Age acceleration was associated with children's direct experience of violence (p = 0.004) and with decreased heart rate (p = 0.002). Children who were predicted to be older than their chronological age had twice as much violence exposure as other children and their heart rate was similar to that of adults. The results remained significant after controlling for demographic variables, such as sex, income and education. This is the first study to show the effects of direct violence exposure on epigenetic aging in children using salivary DNA. Although longitudinal studies are needed to determine whether accelerated epigenetic aging leads to adverse health outcomes later in life, these data point to DNA methylation during childhood as a putative biological mechanism.
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- 2017
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32. Associations between maternal risk factors of adverse pregnancy and birth outcomes and the offspring epigenetic clock of gestational age at birth.
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Girchenko P, Lahti J, Czamara D, Knight AK, Jones MJ, Suarez A, Hämäläinen E, Kajantie E, Laivuori H, Villa PM, Reynolds RM, Kobor MS, Smith AK, Binder EB, and Räikkönen K
- Subjects
- Adult, Epigenesis, Genetic, Female, Humans, Infant, Newborn, Pregnancy, Risk Factors, Birth Weight genetics, DNA Methylation, Gestational Age
- Abstract
Background: A recent study has shown that it is possible to accurately estimate gestational age (GA) at birth from the DNA methylation (DNAm) of fetal umbilical cord blood/newborn blood spots. This DNAm GA predictor may provide additional information relevant to developmental stage. In 814 mother-neonate pairs, we evaluated the associations between DNAm GA and a number of maternal and offspring characteristics. These characteristics reflect prenatal environmental adversity and are expected to influence newborn developmental stage., Results: DNAm GA acceleration (GAA; i.e., older DNAm GA than chronological GA) of the offspring at birth was associated with maternal age of over 40 years at delivery, pre-eclampsia and fetal demise in a previous pregnancy, maternal pre-eclampsia and treatment with antenatal betamethasone in the index pregnancy, lower neonatal birth size, lower 1-min Apgar score, and female sex. DNAm GA deceleration (GAD; i.e., younger DNAm GA than chronological GA) of the offspring at birth was associated with insulin-treated gestational diabetes mellitus (GDM) in a previous pregnancy and Sjögren's syndrome. These findings were more accentuated when the DNAm GA calculation was based on the raw difference between DNAm GA and GA than on the residual from the linear regression of DNAm GA on GA., Conclusions: Our findings show that variations in the DNAm GA of the offspring at birth are associated with a number of maternal and offspring characteristics known to reflect exposure to prenatal environmental adversity. Future studies should be aimed at determining if this biological variation is predictive of developmental adversity.
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- 2017
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33. Gestational age predicted by DNA methylation: potential clinical and research utility.
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Knight AK, Conneely KN, and Smith AK
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- 2017
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34. An epigenetic clock for gestational age at birth based on blood methylation data.
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Knight AK, Craig JM, Theda C, Bækvad-Hansen M, Bybjerg-Grauholm J, Hansen CS, Hollegaard MV, Hougaard DM, Mortensen PB, Weinsheimer SM, Werge TM, Brennan PA, Cubells JF, Newport DJ, Stowe ZN, Cheong JL, Dalach P, Doyle LW, Loke YJ, Baccarelli AA, Just AC, Wright RO, Téllez-Rojo MM, Svensson K, Trevisi L, Kennedy EM, Binder EB, Iurato S, Czamara D, Räikkönen K, Lahti JM, Pesonen AK, Kajantie E, Villa PM, Laivuori H, Hämäläinen E, Park HJ, Bailey LB, Parets SE, Kilaru V, Menon R, Horvath S, Bush NR, LeWinn KZ, Tylavsky FA, Conneely KN, and Smith AK
- Subjects
- Adult, Birth Weight, CpG Islands genetics, Epigenesis, Genetic, Female, Fetal Development genetics, Humans, Infant, Newborn, Male, Pregnancy, Aging genetics, Biomarkers blood, DNA Methylation genetics, Gestational Age
- Abstract
Background: Gestational age is often used as a proxy for developmental maturity by clinicians and researchers alike. DNA methylation has previously been shown to be associated with age and has been used to accurately estimate chronological age in children and adults. In the current study, we examine whether DNA methylation in cord blood can be used to estimate gestational age at birth., Results: We find that gestational age can be accurately estimated from DNA methylation of neonatal cord blood and blood spot samples. We calculate a DNA methylation gestational age using 148 CpG sites selected through elastic net regression in six training datasets. We evaluate predictive accuracy in nine testing datasets and find that the accuracy of the DNA methylation gestational age is consistent with that of gestational age estimates based on established methods, such as ultrasound. We also find that an increased DNA methylation gestational age relative to clinical gestational age is associated with birthweight independent of gestational age, sex, and ancestry., Conclusions: DNA methylation can be used to accurately estimate gestational age at or near birth and may provide additional information relevant to developmental stage. Further studies of this predictor are warranted to determine its utility in clinical settings and for research purposes. When clinical estimates are available this measure may increase accuracy in the testing of hypotheses related to developmental age and other early life circumstances.
- Published
- 2016
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35. Evaluation of laboratory perspectives on hereditary cancer panels.
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Stoll J, Weissman SM, Hook N, Selkirk C, Johnson AK, Newlin A, and Vogel Postula KJ
- Subjects
- Adult, Female, Genetic Counseling, High-Throughput Nucleotide Sequencing, Humans, Male, Middle Aged, Genetic Predisposition to Disease, Genetic Testing, Laboratories, Neoplasms genetics
- Abstract
Genetic counseling and testing for hereditary cancer susceptibility is a rapidly evolving field and partly a result of next-generation sequencing (NGS) allowing analysis of multiple cancer susceptibility genes simultaneously. This qualitative study explored laboratory perspectives on hereditary cancer panels. Semi-structured interviews were conducted with representatives of clinical laboratories offering hereditary cancer panels via NGS. Several themes emerged from the responses pertaining to hereditary cancer panel development, the importance of communication of panel properties with patients, variant reporting policies, and the future of hereditary cancer gene testing. Clinical utility was discussed as primary consideration during panel development. In addition, while participants indicated gene and syndrome overlap prompted panel development in general, laboratories differed in their opinions of whether phenotypic overlap warrants offering pan-cancer panels only versus cancer specific panels. Participants stressed the importance of patients understanding implications of panel testing, including what is tested for and limitations of testing. While all laboratories discussed the limitations of a variant of uncertain significance result, they differed significantly in their reporting methods. This study provides healthcare providers information on the laboratory approach to panel testing, highlighting both commonalities and differences in laboratory approaches, and may allow providers to make more informed decisions when ordering hereditary cancer panels.
- Published
- 2016
- Full Text
- View/download PDF
36. Design of a randomised intervention study: the effect of dumbbell exercise therapy on physical activity and quality of life among breast cancer survivors in Malaysia.
- Author
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Rufa'i AA, Muda WAMW, Yen SH, Abd Shatar AK, Murali BVK, and Tan SW
- Abstract
Background: Participation in physical activity has a positive impact on the overall health and quality of life, whereas physical inactivity is associated with a poor prognosis among breast cancer survivors. Despite the health-enhancing benefits of physical activity, the majority of Malaysian breast cancer survivors are not physically active. This paper presents the design of a randomised study to evaluate the feasibility and effect of exercise therapy intervention using light resistance dumbbell exercise to promote active lifestyle and improve the quality of life of breast cancer survivors in Malaysia., Methods/design: This is an intervention study of a 12-week exercise therapy that will explore and compare the effects of light resistance and aerobic exercise on physical activity level and quality of life components in 102 female breast cancer survivors. Major eligibility criteria include histologically confirmed diagnosis of breast cancer stages I-III, 3-12 months post-diagnosis, and absence of any disorder contraindicating exercise. Participants will be stratified based on menopausal status (pre-menopause vs post-menopause) and then assigned randomly to one of three groups. Participants in group A will participate in a three-times weekly supervised resistance exercise using light resistance dumbbells; participants in group B will participate in a three-times weekly supervised aerobic exercise; while participants in group C (control group) will be given aerobic exercise after completion of the intervention. The primary end points include physical activity level and quality of life components. The secondary end points are body mass index, body composition, total caloric intake, and waist-to-hip ratio., Discussion: Although there have been many studies of resistance exercise in breast cancer survivors, this is the first study using this specific mode of resistance. Findings will contribute data on the feasibility and effects of light resistance dumbbell exercises, and provide knowledge on the physical activity intervention programme that will maximally promote better overall health and well-being of survivors., Competing Interests: Competing interests: None declared.
- Published
- 2016
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37. Improved molecular diagnosis of patients with neonatal diabetes using a combined next-generation sequencing and MS-MLPA approach.
- Author
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Alkorta-Aranburu G, Sukhanova M, Carmody D, Hoffman T, Wysinger L, Keller-Ramey J, Li Z, Johnson AK, Kobiernicki F, Botes S, Fitzpatrick C, Das S, and Del Gaudio D
- Subjects
- Case-Control Studies, Diabetes Mellitus genetics, Follow-Up Studies, Humans, Infant, Newborn, Infant, Newborn, Diseases genetics, Polymerase Chain Reaction, Prognosis, Prospective Studies, Retrospective Studies, Biomarkers metabolism, DNA Methylation, Diabetes Mellitus diagnosis, High-Throughput Nucleotide Sequencing methods, Infant, Newborn, Diseases diagnosis, Molecular Diagnostic Techniques methods, Multiplex Polymerase Chain Reaction methods
- Abstract
Background: We evaluated a methylation-specific multiplex-ligation-dependent probe amplification (MS-MLPA) assay for the molecular diagnosis of transient neonatal diabetes mellitus (TNDM) caused by 6q24 abnormalities and assessed the clinical utility of using this assay in combination with next generation sequencing (NGS) analysis for diagnosing patients with neonatal diabetes (NDM)., Methods: We performed MS-MLPA in 18 control samples and 42 retrospective NDM cases with normal bi-parental inheritance of chromosome 6. Next, we evaluated 22 prospective patients by combining NGS analysis of 11 NDM genes and the MS-MLPA assay., Results: 6q24 aberrations were identified in all controls and in 19% of patients with normal bi-parental inheritance of chromosome 6. The MS-MLPA/NGS combined approach identified a genetic cause in ~64% of patients with NDM of unknown etiology., Conclusions: MS-MLPA is a reliable method to identify all known 6q24 abnormalities and comprehensive testing of all causes reveals a causal mutation in ~64% of patients.
- Published
- 2016
- Full Text
- View/download PDF
38. Reinitiation of mRNA translation in a patient with X-linked infantile spasms with a protein-truncating variant in ARX.
- Author
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Moey C, Topper S, Karn M, Johnson AK, Das S, Vidaurre J, and Shoubridge C
- Subjects
- Codon, Initiator, Genetic Diseases, X-Linked diagnosis, HEK293 Cells, Homeodomain Proteins metabolism, Humans, Infant, Male, Peptide Chain Initiation, Translational, RNA, Messenger metabolism, Siblings, Spasms, Infantile diagnosis, Transcription Factors metabolism, Genetic Diseases, X-Linked genetics, Homeodomain Proteins genetics, Mutation, RNA, Messenger genetics, Spasms, Infantile genetics, Transcription Factors genetics
- Abstract
Mutations in the Aristaless-related homeobox gene (ARX) lead to a range of X-linked intellectual disability phenotypes, with truncating variants generally resulting in severe X-linked lissencephaly with ambiguous genitalia (XLAG), and polyalanine expansions and missense variants resulting in infantile spasms. We report two male patients with early-onset infantile spasms in whom a novel c.34G>T (p.(E12*)) variant was identified in the ARX gene. A similar variant c.81C>G (p.(Y27*)), has previously been described in two affected cousins with early-onset infantile spasms, leading to reinitiation of ARX mRNA translation resulting in an N-terminal truncated protein. We show that the novel c.34G>T (p.(E12*)) variant also reinitiated mRNA translation at the next AUG codon (c.121-123 (p.M41)), producing the same N-terminally truncated protein. The production of both of these truncated proteins was demonstrated to be at markedly reduced levels using in vitro cell assays. Using luciferase reporter assays, we demonstrate that transcriptional repression capacity of ARX was diminished by both the loss of the N-terminal corepressor octapeptide domain, as a consequence of truncation, and the marked reduction in mutant protein expression. Our study indicates that premature termination mutations very early in ARX lead to reinitiation of translation to produce N-terminally truncated protein at markedly reduced levels of expression. We conclude that even low levels of N-terminally truncated ARX is sufficient to improve the patient's phenotype compared with the severe phenotype of XLAG that includes malformations of the brain and genitalia normally seen in complete loss-of-function mutations in ARX.
- Published
- 2016
- Full Text
- View/download PDF
39. Epigenetic Biomarkers of Preterm Birth and Its Risk Factors.
- Author
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Knight AK and Smith AK
- Abstract
A biomarker is a biological measure predictive of a normal or pathogenic process or response. Biomarkers are often useful for making clinical decisions and determining treatment course. One area where such biomarkers would be particularly useful is in identifying women at risk for preterm delivery and related pregnancy complications. Neonates born preterm have significant morbidity and mortality, both in the perinatal period and throughout the life course, and identifying women at risk of delivering preterm may allow for targeted interventions to prevent or delay preterm birth (PTB). In addition to identifying those at increased risk for preterm birth, biomarkers may be able to distinguish neonates at particular risk for future complications due to modifiable environmental factors, such as maternal smoking or alcohol use during pregnancy. Currently, there are no such biomarkers available, though candidate gene and epigenome-wide association studies have identified DNA methylation differences associated with PTB, its risk factors and its long-term outcomes. Further biomarker development is crucial to reducing the health burden associated with adverse intrauterine conditions and preterm birth, and the results of recent DNA methylation studies may advance that goal.
- Published
- 2016
- Full Text
- View/download PDF
40. A novel mutation in the promoter of RARS2 causes pontocerebellar hypoplasia in two siblings.
- Author
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Li Z, Schonberg R, Guidugli L, Johnson AK, Arnovitz S, Yang S, Scafidi J, Summar ML, Vezina G, Das S, Chapman K, and del Gaudio D
- Subjects
- Base Sequence, Cerebellar Diseases diagnosis, Cerebellar Diseases genetics, Child, Preschool, DNA Mutational Analysis, Female, Genetic Association Studies, Humans, Infant, Male, Molecular Sequence Data, Mutation, Missense, Point Mutation, Arginine-tRNA Ligase genetics, Promoter Regions, Genetic
- Abstract
Pontocerebellar hypoplasia (PCH) is characterized by hypoplasia and atrophy of the cerebellum, variable pontine atrophy, microcephaly, severe mental and motor impairments and seizures. Mutations in 11 genes have been reported in 8 out of 10 forms of PCH. Recessive mutations in the mitochondrial arginyl-transfer RNA synthetase gene (RARS2) have been recently associated with PCH type 6, which is characterized by early-onset encephalopathy with signs of oxidative phosphorylation defect. Here we describe the clinical presentation, neuroimaging findings and molecular characterizations of two siblings with a clinical diagnosis of PCH who displayed a novel variant (c.-2A>G) in the 5'-UTR of the RARS2 gene in the homozygous state. This variant was identified through next-generation sequencing testing of a panel of nine genes known to be involved in PCH. Gene expression and functional studies demonstrated that the c.-2A>G sequence change directly leads to a reduced RARS2 messenger RNA expression in the patients by decreasing RARS2 promoter activity, thus providing evidence that mutations in the RARS2 promoter are likely to represent a new causal mechanism of PCH6.
- Published
- 2015
- Full Text
- View/download PDF
41. Clinical utility of next-generation sequencing for the molecular diagnosis of monogenic diabetes.
- Author
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Johnson AK and Gaudio DD
- Abstract
Monogenic diabetes resulting from mutations that primarily reduce insulin-secreting pancreatic β-cell function accounts for 1-2% of all cases of diabetes, and is genetically and clinically heterogeneous. Currently, genetic testing for monogenic diabetes relies on selection of the appropriate gene for analysis based on the availability of comprehensive phenotypic information, which can be time consuming, costly and can limit the differential diagnosis to a few selected genes. In recent years, the exponential growth in the field of high-throughput capture and sequencing technology has made it possible and cost effective to sequence many genes simultaneously, making it an efficient diagnostic tool for clinically and genetically heterogeneous disorders such as monogenic diabetes. Making a diagnosis of monogenic diabetes is important as it enables more appropriate treatment, better prediction of disease prognosis and progression, and counseling and screening of family members. We provide a concise overview of the genetic etiology of some forms of monogenic diabetes, as well as a discussion of the clinical utility of genetic testing by comprehensive multigene panel using next-generation sequencing methodologies.
- Published
- 2014
- Full Text
- View/download PDF
42. Complementary and alternative medicines (CAM) disclosure to the health care providers: a qualitative insight from Malaysian cancer patients.
- Author
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Farooqui M, Hassali MA, Abdul Shatar AK, Shafie AA, Farooqui MA, Saleem F, and Aljadhey H
- Subjects
- Adult, Aged, Data Collection, Female, Humans, Malaysia, Male, Middle Aged, Patient Preference, Physician-Patient Relations, Young Adult, Complementary Therapies statistics & numerical data, Neoplasms therapy, Truth Disclosure
- Abstract
This study sought to evaluate Malaysian oncology patients CAM disclosure to the health care providers. Patients were interviewed across three major Malaysian ethnic groups, Malay, Chinese and Indian. Thematic content analysis identified three themes: reasons of CAM disclosure, reasons of CAM non-disclosure and preference of CAM discussion to health care providers. Patients agreed that CAM disclosure is important to avoid any interaction with the conventional medicines. Perceived lack of physicians' knowledge & interest in CAM, fear of termination of therapy by the physicians upon CAM disclosure, and perceived simplicity of some of the CAM therapies were among the reasons of non-disclosure. Given the option of oncologists, pharmacists or nurses, patients described oncologists as the most suitable person to discuss or disclose CAM use due to confidence in their clinical skills. Understanding the underlying beliefs of patients' reluctance to disclose CAM to health care providers is important especially when they are on an ongoing treatment for cancer., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
43. Innovation: Can you afford to ignore reserch and development?
- Author
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Jackson AK
- Subjects
- Humans, State Medicine trends, Time Factors, United Kingdom, Epidemiologic Research Design, Health Services Research, Outcome Assessment, Health Care, State Medicine standards
- Published
- 2012
44. Complementary and Alternative Medicine (CAM) use by Malaysian oncology patients.
- Author
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Farooqui M, Hassali MA, Abdul Shatar AK, Shafie AA, Seang TB, and Farooqui MA
- Subjects
- Adult, Aged, Complementary Therapies adverse effects, Complementary Therapies methods, Female, Humans, Malaysia, Male, Medicine, East Asian Traditional adverse effects, Medicine, East Asian Traditional methods, Middle Aged, Neoplasms ethnology, Young Adult, Complementary Therapies statistics & numerical data, Decision Making, Health Knowledge, Attitudes, Practice, Neoplasms therapy
- Abstract
The current study sought to evaluate Malaysian oncology patients' decision making about the use of Complementary and Alternative Medicine (CAM) for the management of their care. Patients were interviewed across three major Malaysian ethnic groups, Malay, Chinese and Indian. Thematic content analysis identified four central themes: Conceptualizing CAM, the decision making process; rationale given for selecting or rejecting CAM and barriers to CAM use. Participants generally used the term 'traditional medicine', referred to locally as 'ubat kampung', meaning medicine derived from 'local traditions'. Mixed reactions were shown concerning the effectiveness of CAM to cure cancer and the slow progression of CAM results and treatment costs were cited as major barriers to CAM use. Concerns regarding safety and efficacy of CAM in ameliorating cancer as well as potential interactions with conventional therapies highlighted the importance of patients' knowledge about cancer treatments., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
45. A functional role for CCR6 on proallergic T cells in the gastrointestinal tract.
- Author
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Blázquez AB, Knight AK, Getachew H, Bromberg JS, Lira SA, Mayer L, and Berin MC
- Subjects
- Adoptive Transfer, Animals, Antibodies pharmacology, CD3 Complex immunology, Cells, Cultured, Chemokine CCL20 immunology, Cholera Toxin toxicity, Diarrhea chemically induced, Female, Fingolimod Hydrochloride, Immunoglobulin E immunology, Immunosuppressive Agents pharmacology, Lymph Nodes cytology, Lymph Nodes immunology, Mast Cells immunology, Mice, Mice, Inbred BALB C, Mice, Mutant Strains, Ovalbumin immunology, Ovalbumin pharmacology, Propylene Glycols pharmacology, Receptors, CCR6 genetics, Sphingosine analogs & derivatives, Sphingosine pharmacology, Diarrhea immunology, Food Hypersensitivity immunology, Jejunum immunology, Receptors, CCR6 immunology, Th2 Cells immunology
- Abstract
Background & Aims: CCL20 is a chemokine that regulates the homeostatic and inflammatory trafficking of leukocytes to the small intestine and regulates the development of the gastrointestinal lymphoid architecture. T cells expressing T helper cell (Th) 2 cytokines are critical for experimental food allergy, and we hypothesized that CCL20 is involved in the localization of these cells to the gut., Methods: We evaluated the role of CCR6 in allergic diarrhea induced by sensitization and oral challenge with ovalbumin (OVA) using CCR6(+/+) and CCR6(-/-) mice., Results: CCR6(-/-) mice were protected from OVA-induced diarrhea but surprisingly were not impaired in mastocytosis or allergen-specific immunoglobulin E. CCR6(-/-) mice were also protected from T cell-mediated diarrhea induced by anti-CD3 antibody. Allergic diarrhea was associated with an increased expression of Th2 cytokines within the intestinal mucosa that was significantly reduced in CCR6(-/-) mice. Inhibition of lymphocyte homing by treatment with FTY720 did not impair allergic diarrhea, indicating that reactivation of T cells could occur locally within the small intestine. Finally, T-cell transfer studies demonstrated that CCR6 was required both on the transferred T cells and in the recipient mouse to manifest allergic disease in the gastrointestinal tract., Conclusions: These studies highlight a mast cell- and immunoglobulin E-independent role for CCR6-bearing T cells in the pathogenesis of gastrointestinal allergic disease., (Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
46. Immunodeficiencies.
- Author
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Ballow M, Notarangelo L, Grimbacher B, Cunningham-Rundles C, Stein M, Helbert M, Gathmann B, Kindle G, Knight AK, Ochs HD, Sullivan K, and Franco JL
- Subjects
- Antibodies, Bacterial blood, Bacterial Infections immunology, Bacterial Infections prevention & control, Databases, Factual, Humans, Immunoglobulins, Intravenous immunology, Immunoglobulins, Intravenous therapeutic use, Immunologic Deficiency Syndromes complications, Immunologic Deficiency Syndromes epidemiology, Immunologic Deficiency Syndromes therapy, International Cooperation, Opportunistic Infections immunology, Opportunistic Infections prevention & control, Registries, Immunologic Deficiency Syndromes diagnosis
- Abstract
Primary immunodeficiencies (PIDs) are uncommon, chronic and severe disorders of the immune system in which patients cannot mount a sufficiently protective immune response, leading to an increased susceptibility to infections. The treatment of choice for PID patients with predominant antibody deficiency is intravenous immunoglobulin (Ig) replacement therapy. Despite major advances over the last 20 years in the molecular characterization of PIDs, many patients remain undiagnosed or are diagnosed too late, with severe consequences. Various strategies to ensure timely diagnosis of PIDs are in place, and novel approaches are being developed. In recent years, several patient registries have been established. Such registries shed light on the pathology and natural history of these varied disorders. Analyses of the registry data may also reveal which patients are likely to respond well to higher Ig infusion rates and may help to determine the optimal dosing of Ig products. Faster infusion rates may lead to improved convenience for patients and thus increase patient compliance, and may reduce nursing time and the need for hospital resources. Data from two recent studies suggest that Gamunex and Privigen are well tolerated at high infusion rates. Nevertheless, careful selection of patients for high infusion rates, based on co-morbid conditions and tolerance of the current infusion rate, is advisable. Based on the available data, intravenous Ig offers broad protection against encapsulated organisms. As vaccine trends change, careful monitoring of specific antibody levels in the general population, such as those against pneumococcal and meningococcal bacteria, should be implemented.
- Published
- 2009
- Full Text
- View/download PDF
47. Performance evaluation of a miniature ion mobility spectrometer drift cell for application in hand-held explosives detection ion mobility spectrometers.
- Author
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Babis JS, Sperline RP, Knight AK, Jones DA, Gresham CA, and Denton MB
- Abstract
The implementation of hand-held ion mobility spectrometers (IMS) requires the development and evaluation of miniature drift cells providing high sensitivity while maintaining reasonable resolution. This manuscript describes the construction of a miniature IMS designed for such an application and its characterization by evaluation of the detection limits and resolution of the system with seven explosive compounds including trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), pentaerythritol tetranitrate (PETN), 2,4,6-trinitrophenyl-N-methylnitramine (Tetryl), nitroglycerin (NG), 2,4-dinitrotoluene (2,4 DNT), and 2,6-dinitrotoluene (2,6 DNT).
- Published
- 2009
- Full Text
- View/download PDF
48. Toll-like receptor 7 and 9 defects in common variable immunodeficiency.
- Author
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Yu JE, Knight AK, Radigan L, Marron TU, Zhang L, Sanchez-Ramón S, and Cunningham-Rundles C
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, B-Lymphocyte Subsets drug effects, B-Lymphocyte Subsets metabolism, Cell Differentiation drug effects, Cell Differentiation immunology, Cell Proliferation drug effects, Common Variable Immunodeficiency immunology, Dendritic Cells drug effects, Dendritic Cells immunology, Dendritic Cells metabolism, Female, Fibroblasts drug effects, Fibroblasts immunology, Fibroblasts metabolism, Guanosine analogs & derivatives, Guanosine pharmacology, Humans, Immunoglobulin Class Switching drug effects, Immunoglobulin Class Switching immunology, Interferon-alpha biosynthesis, Interferon-alpha immunology, Interferon-alpha pharmacology, Interferon-beta biosynthesis, Interferon-beta immunology, Interleukin-12 biosynthesis, Interleukin-12 immunology, Interleukin-6 biosynthesis, Interleukin-6 immunology, Leukocytes, Mononuclear drug effects, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear metabolism, Ligands, Lymphocyte Activation drug effects, Lymphocyte Activation immunology, Male, Middle Aged, Poly I-C pharmacology, Toll-Like Receptor 7 agonists, Toll-Like Receptor 7 immunology, Toll-Like Receptor 9 agonists, Toll-Like Receptor 9 immunology, Tumor Necrosis Factor-alpha biosynthesis, Tumor Necrosis Factor-alpha immunology, Young Adult, B-Lymphocyte Subsets immunology, Common Variable Immunodeficiency metabolism, Toll-Like Receptor 7 metabolism, Toll-Like Receptor 9 metabolism
- Abstract
Background: Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia, reduced numbers of peripheral blood isotype-switched memory B cells, and loss of plasma cells., Objective: Because Toll-like receptor (TLR) activation of B cells can initiate and potentially sustain normal B cell functions, we examined functional outcomes of TLR7 and TLR9 signaling in CVID B cells., Methods: TLR7-mediated, TLR7/8-mediated, and TLR9-mediated cell proliferation, isotype switch, and immunoglobulin production by control and CVID B cells or isolated naive and memory B cell subsets were examined. We quantitated TNF-alpha, IL-6, and IL-12 production in response to TLR1-9 ligands and measured IFN-alpha production by TLR7-stimulated PBMCs and isolated plasmacytoid dendritic cells (pDCs). IFN-beta mRNA expression by TLR3-stimulated fibroblasts was assessed., Results: Unlike CD27(+) B cells of controls, TLR7-activated, TLR7/8-activated, or TLR9-activated CVID B cells or isolated CD27(+) B cells did not proliferate, upregulate CD27, or shed surface IgD. TLR-stimulated CVID B cells failed to upregulate activation-induced cytosine deaminase mRNA or produce IgG and IgA. TLR7-stimulated PBMCs and pDCs produced little or no IFN-alpha. Reconstituting IFN-alpha in TLR7-stimulated CVID B-cell cultures facilitated proliferation, CD27 upregulation, and isotype switch. These TLR defects are restricted because CVID PBMCs stimulated with TLR ligands produced normal amounts of TNF-alpha, IL-6, and IL-12; TLR3-mediated expression of IFN-beta by CVID fibroblasts was normal., Conclusion: Defective TLR7 and TLR9 signaling in CVID B cells and pDCs, coupled with deficient IFN-alpha, impairs CVID B cell functions and prevents TLR-mediated augmentation of humoral immunity in vivo.
- Published
- 2009
- Full Text
- View/download PDF
49. Pathophysiology of food-induced anaphylaxis.
- Author
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Lemon-Mulé H, Nowak-Wegrzyn A, Berin C, and Knight AK
- Subjects
- Anaphylaxis diagnosis, Anaphylaxis physiopathology, Anaphylaxis therapy, Animals, Antigens metabolism, Basophils physiology, Disease Models, Animal, Food Hypersensitivity diagnosis, Food Hypersensitivity etiology, Food Hypersensitivity physiopathology, Food Hypersensitivity therapy, Humans, Immunoglobulin E immunology, Mast Cells physiology, Anaphylaxis etiology
- Abstract
Food-induced anaphylaxis is a steadily increasing problem in westernized countries and now represents the leading cause of anaphylaxis in the outpatient setting, particularly in children. Much of our knowledge of the pathophysiology of food-induced anaphylaxis comes from animal studies. Food anaphylaxis in humans is thought to be entirely IgE mediated. Several features appear to be unique to these reactions; factors such as exercise can lower the "threshold" for anaphylaxis in certain susceptible individuals. Different methods of thermal processing can modify the allergenicity of food proteins. Alteration of stomach pH can allow for incomplete digestion of food proteins, leading to increased absorption of intact food allergens. Low serum platelet-activating factor acetylhydrolase may predispose to fatal food-induced anaphylaxis. With a greater understanding of the pathophysiology of food-induced anaphylaxis, novel approaches not only to identify those at risk, but to treat and ultimately prevent food-induced anaphylaxis, are on the horizon.
- Published
- 2008
- Full Text
- View/download PDF
50. A boy with fever, lymphadenopathy, hepatosplenomegaly, and lymphocytosis.
- Author
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Kaza U, Knight AK, Jeroudi M, Bocchini JA Jr, Anga A, and Bahna SL
- Subjects
- Antibodies, Monoclonal therapeutic use, Antibodies, Monoclonal, Murine-Derived, Child, Preschool, Cyclosporine therapeutic use, Dexamethasone therapeutic use, Diagnosis, Differential, Epstein-Barr Virus Infections diagnosis, Epstein-Barr Virus Infections drug therapy, Etoposide therapeutic use, Fever, Hepatomegaly diagnosis, Humans, Lymphatic Diseases, Lymphocytosis diagnosis, Lymphohistiocytosis, Hemophagocytic drug therapy, Male, Rituximab, Splenomegaly diagnosis, Lymphohistiocytosis, Hemophagocytic diagnosis
- Abstract
Proliferation of the lymphoid system should arouse suspicion of a potentially serious illness. We present a 4.5-year-old boy who developed fever, vomiting, diarrhea, lymphadenopathy, hepatosplenomegaly, lymphocytosis, anemia, thrombocytopenia, and increased liver enzymes. Lymph node and bone marrow biopsies showed lymphoproliferation, Epstein-Barr virus (EBV) infection, and hemophagocytosis leading to the diagnosis of hemophagocytic lymphohistiocytosis (HLH). Chemotherapy was initiated for HLH with dexamethasone, etoposide, and cyclosporine. Because of a high level of EBV viremia, rituximab was added a few days later and resulted in a remarkable drop in the EBV in the circulation but not in the cerebrospinal fluid. However, the patient succumbed to encephalitis, pneumonia, and cardiopulmonary failure. Autopsy revealed the presence of EBV in the brain, indicating the ineffectiveness of rituximab therapy in treating central nervous system infection with EBV.
- Published
- 2008
- Full Text
- View/download PDF
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