Search

Background: The World Health Organization (WHO) recommends immediate initiation of lifelong antiretroviral therapy (ART) for all people living with HIV, including pregnant women. As a result, an increasing number of women living with HIV conceive while taking ART, the vast majority of whom reside in low‐ and middle‐income countries (LMICs). We aimed to assess the association between timing of ART initiation and perinatal outcomes. Methods: We conducted a systematic literature review by searching PubMed, CINAHL (EBSCOhost), Global Health (Ovid), EMBASE (Ovid), and the Cochrane Central Register of Controlled Trials and four clinical trial databases (WHO International Clinical Trials Registry Platform, the Pan African Clinical Trials Registry, the ClinicalTrials.gov database, and the ISRCTN Registry) from 1 January 1980 to 28 April 2018. We identified studies reporting specific perinatal outcomes among pregnant women living with HIV according to timing of ART initiation and extracted data. Perinatal outcomes assessed were preterm birth (<37 weeks), very preterm birth (<32 weeks), low birthweight (<2500 g), very low birthweight (<1500 g), small for gestational age (<10th centile), very small for gestational age (<3rd centile) and neonatal death (<29 days). Random‐effects meta‐analyses examined perinatal outcomes associated with preconception and antenatal ART initiation as well as according to trimesters of antenatal initiation. We performed quality assessments and subgroup and sensitivity analyses, and assessed the effect of adjustment for confounders. This systematic review and meta‐analyses is registered with PROSPERO, number CRD42021248987. Results: Of 51 874 unique citations, 25 studies (eight prospective and 17 retrospective cohort studies) were eligible for analysis, including 40 920 women living with HIV. Preconception ART initiation was associated with a significantly increased risk of preterm birth (relative risk 1.16; 95% confidence interval [CI] 1.03–1.31) compared with antenatal ART initiation. Preconception ART initiation was not significantly associated with very preterm birth, low birthweight, very low birthweight, small for gestational age, very small for gestational age, or neonatal death. First trimester exposure (i.e. preconception or first trimester initiation) was not significantly associated with any increased risk of adverse perinatal outcomes. No significant association between timing of ART initiation and adverse perinatal outcomes was found in the studies of higher quality and those conducted in LMICs. Conclusion: Preconception ART initiation is associated with preterm birth but no other adverse perinatal outcomes. In LMICs, where most pregnant women living with HIV reside, the timing of ART initiation was not associated with any adverse perinatal outcomes. [ABSTRACT FROM AUTHOR]

Background: The global rise in cesarean sections has led to increasing numbers of pregnant women with a history of previous cesarean section. Policy in many high-income settings supports offering these women a choice between planned elective repeat cesarean section (ERCS) or planned vaginal birth after previous cesarean (VBAC), in the absence of contraindications to VBAC. Despite the potential for this choice to affect women's subsequent risk of experiencing pelvic floor disorders, evidence on the associated effects to fully counsel women is lacking. This study investigated the association between planned mode of birth after previous cesarean section and the woman's subsequent risk of undergoing pelvic floor surgery.Methods and Findings: A population-based cohort study of 47,414 singleton term births in Scotland between 1983 to 1996 to women with 1 or more previous cesarean sections was conducted using linked Scottish national routine datasets. Cox regression was used to investigate the association between planned as well as actual mode of birth and women's subsequent risk of having any pelvic floor surgery and specific types of pelvic floor surgery adjusted for sociodemographic, maternal medical, and obstetric-related factors. Over a median of 22.1 years of follow-up, 1,159 (2.44%) of the study population had pelvic floor surgery. The crude incidence rate of any pelvic floor surgery per 1,000 person-years was 1.35, 95% confidence interval (CI) 1.27 to 1.43 in the overall study population, 1.75, 95% CI 1.64 to 1.86 in the planned VBAC group and 0.66, 95% CI 0.57 to 0.75 in the ERCS group. Planned VBAC compared to ERCS was associated with a greater than 2-fold increased risk of the woman undergoing any pelvic floor surgery (adjusted hazard ratio [aHR] 2.38, 95% CI 2.03 to 2.80, p < 0.001) and a 2- to 3-fold increased risk of the woman having surgery for pelvic organ prolapse or urinary incontinence (aHR 3.17, 95% CI 2.47 to 4.09, p < 0.001 and aHR 2.26, 95% CI 1.79 to 2.84, p < 0.001, respectively). Analysis by actual mode of birth showed these increased risks were only apparent in the women who actually had a VBAC, with the women who needed an in-labor non-elective repeat cesarean section having a comparable risk of pelvic floor surgery to those who had an ERCS. The main limitation of this study is the potential for misclassification bias.Conclusions: This study suggests that among women with previous cesarean section giving birth to a singleton at term, planned VBAC compared to ERCS is associated with an increased risk of the woman subsequently undergoing pelvic floor surgery including surgery for pelvic organ prolapse and urinary incontinence. However, these risks appear to be only apparent in women who actually give birth vaginally as planned, highlighting the role of vaginal birth rather than labor in pelvic floor dysfunction requiring surgery. The findings provide useful additional information to counsel women with previous cesarean section about the risks and benefits associated with their future birth choices. [ABSTRACT FROM AUTHOR]

Global HIV-1 genetic diversity forms a major obstacle to the development of an HIV vaccine. It may be necessary to employ subtype-specific HIV-1 vaccines in individual countries according to their HIV-1 subtype distribution. We estimated the global and regional need for subtype-specific HIV-1 vaccines. We took into account the proportions of different HIV-1 variants circulating in each country, the genetic composition of HIV-1 recombinants, and the different genome segments (gag , pol , env) that may be incorporated into vaccines. We modeled different scenarios according to whether countries would employ subtype-specific HIV-1 vaccines against (1) the most common subtype; (2) subtypes contributing more than 5% of HIV infections; or (3) all circulating subtypes. For therapeutic vaccines targeting the most common HIV-1 subtype in each country, 16.5 million doses of subtype C vaccine were estimated globally, followed by subtypes A (14.3 million) and B (4.2 million). A vaccine based on env required 2.6 million subtype E doses, and a vaccine based on pol required 4.8 million subtype G doses. For prophylactic vaccines targeting the most common HIV-1 subtype in each country, 1.9 billion doses of subtype A vaccine were estimated globally, followed by subtype C (1.1 billion) and subtype B (1.0 billion). A vaccine based on env required 1.2 billion subtype E doses, and a vaccine based on pol required 0.3 billion subtype G doses. If subtype-specific HIV-1 vaccines are also directed against less common subtypes in each country, vaccines targeting subtypes D, F, H, and K are also needed and would require up to five times more vaccine doses in total. We conclude that to provide global coverage, subtype-specific HIV-1 vaccines need to be directed against subtypes A, B, and C. Vaccines targeting env also need to include subtype E and those targeting pol need to include subtype G. [ABSTRACT FROM AUTHOR]

The global diversity of HIV forms a major challenge to the development of an HIV vaccine, as well as diagnostic, drug resistance, and viral load assays, which are essential to reaching the UNAIDS 90:90:90 targets. We sought to determine country level HIV-1 diversity globally between 1990 and 2015. We assembled a global HIV-1 molecular epidemiology database through a systematic literature search and a global survey. We searched PubMed, EMBASE (Ovid), CINAHL (Ebscohost), and Global Health (Ovid) for HIV-1 subtyping studies published from 1 January 1990 to 31 December 2015. We collected additional unpublished data through a global survey of experts. Prevalence studies with original HIV-1 subtyping data collected between 1990 and 2015 were included. This resulted in a database with 383,519 subtyped HIV-1 samples from 116 countries over four time periods (1990 to 1999, 2000 to 2004, 2005 to 2009, and 2010 to 2015). We analyzed country-specific numbers of distinct HIV-1 subtypes, circulating recombinant forms (CRFs), and unique recombinant forms (URFs) in each time period. We also analyzed country-specific proportions of infections due to HIV-1 recombinants, CRFs, and URFs and calculated the Shannon diversity index for each country. Finally, we analyzed global temporal trends in each of these measures of HIV-1 diversity. We found extremely wide variation in complexity of country level HIV diversity around the world. Central African countries such as Chad, Democratic Republic of the Congo, Angola, and Republic of the Congo have the most diverse HIV epidemics. The number of distinct HIV-1 subtypes and recombinants was greatest in Western Europe (Spain and France) and North America (United States) (up to 39 distinct HIV-1 variants in Spain). The proportion of HIV-1 infections due to recombinants was highest in Southeast Asia (-95% of infections in Viet Nam, Cambodia, and Thailand), China, and West and Central Africa, mainly due to high proportions of CRF01_AE and CRF02_AG. Other CRFs played major roles (-75% of HIV-1 infections) in Estonia (CRF06_cpx), Iran (CRF35_AD), and Algeria (CRF06_cpx). The highest proportions of URFs (-30%) were found in Myanmar, Republic of the Congo, and Argentina. Global temporal analysis showed consistent increases over time in country level numbers of distinct HIV-1 variants and proportions of CRFs and URFs, leading to increases in country level HIV-1 diversity. Our study provides epidemiological evidence that the HIV pandemic is diversifying at country level and highlights the increasing challenge to prevention and treatment efforts. HIV-1 molecular epidemiological surveillance needs to be continued and improved. [ABSTRACT FROM AUTHOR]

Background: Preterm birth is the leading cause of neonatal and child mortality worldwide. Maternal HIV infection and antiretroviral treatment (ART) increase the rate of preterm birth, but the underlying mechanisms remain unknown, limiting progress in prediction, prevention and treatment. While overall γδ T cell levels remain constant, acute HIV infection is associated with a depletion of the Vδ2 subset and an increase in the Vδ1 subset, which do not return to baseline with ART. γδ T cells have also been implicated in adverse pregnancy outcomes and we therefore investigated the potential association between maternal HIV infection, peripheral γδ T cell frequencies and preterm birth. Methods: Study participants were HIV positive (n = 47) and HIV negative (n = 45) women enrolled in a prospective pregnancy cohort study at Chris Hani Baragwanath Academic Hospital in Soweto, South Africa. Women were enrolled in early pregnancy and gestational age was accurately determined by first trimester ultrasound scan. Peripheral blood samples were collected in each trimester and peripheral blood mononuclear cells isolated. Frequencies of γδ T cells, Vδ1+ and Vδ2+ γδ T cell subsets, and CCR6 chemokine receptor expression were determined by flow cytometry. Results: Total γδ T cell levels were similar between HIV positive and HIV negative women throughout pregnancy. However, in each trimester maternal HIV infection was associated with reduced levels of the Vδ2+ subset and increased levels of the Vδ1+ subset, leading to a reversal of the Vδ1/Vδ2 ratio. Timing of ART initiation among HIV positive women did not affect levels of γδ T cells, the Vδ1+ and Vδ2+ subsets, or the Vδ1/Vδ2 ratio. Importantly, preterm birth was associated with lower total γδ T cell levels in early pregnancy and γδ T cell frequencies were lowest in HIV positive women who delivered preterm. Moreover, in the first trimester the proportion of Vδ1+ T cells that were CCR6+ was significantly reduced in HIV+ women and women who delivered preterm, resulting in the lowest proportion of CCR6+ Vδ1 T cells in HIV positive women who delivered preterm. Conclusions: Our findings suggest that altered γδ T cell frequencies may link maternal HIV infection and preterm birth. γδ T cell frequencies in early pregnancy may serve as predictive biomarkers to identify women at risk of delivering preterm. [ABSTRACT FROM AUTHOR]

Problem: Human immunodeficiency virus (HIV) infection is associated with an increased risk of adverse pregnancy outcomes, including preterm birth (PTB), despite viral suppression with antiretroviral therapy. Mucosal‐associated invariant T (MAIT) cells are an immune cell subset involved in antimicrobial immunity at mucosal surfaces. MAIT cells have been found at the maternal‐foetal interface, and MAIT cells are typically depleted early in HIV infection. We aimed to investigate changes in MAIT cells in relation to maternal HIV/ART status and PTB. Method of Study: We conducted flow cytometric analysis of peripheral blood samples from 47 HIV‐positive (HIV+) and 45 HIV‐negative (HIV−) pregnant women enrolled in a prospective pregnancy cohort study in Soweto, South Africa. Frequencies of Vα7.2+ CD161++ MAIT cells and proportions of CD4+, CD8+ and double‐negative MAIT cells were compared between women with and without HIV infection, and between women with and without PTB or spontaneous preterm labour (Sp‐PTL). Results: Although overall MAIT cell frequencies were the same between HIV+ and HIV− patients, HIV+ patients had a higher proportion of CD8+ MAIT cells in the first two trimesters. Women with PTB and Sp‐PTL also had a higher proportion of CD8+ MAIT cells in the first trimester compared to women without these outcomes. The association between changes in MAIT cell subsets and PTB/Sp‐PTL was present in both HIV+ and HIV− women, and an additive effect on MAIT cell subsets was seen in women with both HIV infection and PTB. Conclusions: Interactions between HIV‐related and pregnancy‐related changes in MAIT cell subsets and distribution may lead to imbalances in peripheral MAIT cell subsets in early pregnancy. This may contribute to the increased risk of PTB in HIV+ patients by altering the overall functionality of the peripheral MAIT cell compartment. [ABSTRACT FROM AUTHOR]

Recent studies have suggested greater HIV cure potential among infected children than adults. A major obstacle to HIV eradication in adults is that the viral reservoir is largely comprised of HIV-specific cytotoxic T lymphocyte (CTL) escape variants. We here evaluate the potential for CTL in HIV-infected slow-progressor children to play an effective role in “shock-and-kill” cure strategies. Two distinct subgroups of children were identified on the basis of viral load. Unexpectedly, in both groups, as in adults, HIV-specific CTL drove the selection of escape variants across a range of epitopes within the first weeks of infection. However, in HIV-infected children, but not adults, de novo autologous variant-specific CTL responses were generated, enabling the pediatric immune system to “corner” the virus. Thus, even when escape variants are selected in early infection, the capacity in children to generate variant-specific anti-HIV CTL responses maintains the potential for CTL to contribute to effective shock-and-kill cure strategies in pediatric HIV infection.

Modification of proteins by ubiquitin (Ub)-like proteins (UBLs) plays an important role in many cellular processes, including cell cycle progression, nuclear transport, and autophagy. Protein modification occurs via UBL-conjugating and -deconjugating enzymes, which presumably exert a regulatory function by determining the conjugation status of the substrate proteins. To target and identify UBL-modifying enzymes, we produced Nedd8, ISG15, and SUMO-1 in Escherichia coli and equipped them with a C-terminal electrophilic trap (vinyl sulfone [VS]) via an intein-based method. These C-terminally modified UBL probes reacted with purified UBL-activating (E1), -conjugating (E2), and -deconjugating enzymes in a covalent fashion. Modified UBLs were radioiodinated and incubated with cell lysates prepared from mouse cell lines and tissues to allow visualization of polypeptides reactive with individual UBL probes. The cell type- and tissue-specific labeling patterns observed for the UBL probes reflect distinct expression profiles of active enzymes, indicating tissuespecific functions of UBLs. We identify Ub C-terminal hydrolase L1 (UCH-L1) and DEN1/NEDP1/SENP8, in addition to UCH-L3, as proteases with specificity for Nedd8. The Ub-specific protease isopeptidase T/USP5 is shown to react with ISG15-VS. Furthermore, we demonstrate that the desumoylation enzyme SuPr-1 can be modified by SUMO-1-VS, a modification that is dependent on the SuPr-1 active-site cysteine. The UBL probes described here will be valuable tools for the further characterization of the enzymatic pathways that govern modification by UBLs. [ABSTRACT FROM AUTHOR]

Objective: Increasingly, pregnant women living with HIV (WLHIV) initiate antiretroviral therapy (ART) before conception. We assessed the risk of adverse perinatal outcomes among pregnant WLHIV initiating ART preconception or antenatally, compared with women without HIV or ART-naïve WLHIV., Design: Systematic review and meta-analysis., Methods: We searched PubMed, EMBASE, CINAHL, and Global Health for studies published between 1/1/1980 and 14/7/2023. We assessed the association of preconception/antenatal ART initiation with preterm birth (PTB), very PTB (VPTB), spontaneous PTB (sPTB), low birthweight (LBW), very LBW (VLBW), small-for-gestational-age (SGA), very SGA (VSGA), stillbirth and neonatal death (NND). Data were analysed using random effects meta-analyses. Quality assessments, subgroup and sensitivity analyses were conducted. PROSPERO registration: CRD42021248987., Results: Thirty-one cohort studies were eligible, including 199,156 women in 19 countries. WLHIV with preconception ART were associated with increased risk of PTB (risk ratio 1.55; 95%CI 1.27-1.90), VPTB (2.14,1.02-4.47), LBW (2.19, 1.32-3.63), VLBW (3.34, 1.08-10.35), SGA (1.92, 1.01-3.66), and VSGA (2.79, 1.04-7.47), compared with women without HIV. WLHIV with antenatal ART were associated with increased risk of PTB (1.35, 1.15-1.58), LBW (2.16, 1.39-3.34), VLBW (1.97, 1.01-3.84), SGA (1.77, 1.10-2.84), and VSGA (1.21, 1.09-1.33), compared with women without HIV. Compared to ART-naïve WLHIV, WLHIV with preconception or antenatal ART were associated with increased risk of SGA (preconception: 1.40, 1.12-1.73; antenatal: 1.39, 1.11-1.74) and VSGA (preconception: 2.44, 1.63-3.66; antenatal: 2.24, 1.48-3.40)., Conclusion: Among WLHIV, both preconception and antenatal initiation of ART are associated with increased risks of adverse perinatal outcomes, compared to women without HIV and ART-naïve WLHIV., (Copyright © 2025 The Author(s). Published by Wolters Kluwer Health, Inc.)

We aimed to develop, train, and validate machine learning models for predicting preterm birth (<37 weeks' gestation) in singleton pregnancies at different gestational intervals. Models were developed based on complete data from 22,603 singleton pregnancies from a prospective population-based cohort study that was conducted in 51 midwifery clinics and hospitals in Wenzhou City of China between 2014 and 2016. We applied Catboost, Random Forest, Stacked Model, Deep Neural Networks (DNN), and Support Vector Machine (SVM) algorithms, as well as logistic regression, to conduct feature selection and predictive modeling. Feature selection was implemented based on permutation-based feature importance lists derived from the machine learning models including all features, using a balanced training data set. To develop prediction models, the top 10%, 25%, and 50% most important predictive features were selected. Prediction models were developed with the training data set with 5-fold cross-validation for internal validation. Model performance was assessed using area under the receiver operating curve (AUC) values. The CatBoost-based prediction model after 26 weeks' gestation performed best with an AUC value of 0.70 (0.67, 0.73), accuracy of 0.81, sensitivity of 0.47, and specificity of 0.83. Number of antenatal care visits before 24 weeks' gestation, aspartate aminotransferase level at registration, symphysis fundal height, maternal weight, abdominal circumference, and blood pressure emerged as strong predictors after 26 completed weeks. The application of machine learning on pregnancy surveillance data is a promising approach to predict preterm birth and we identified several modifiable antenatal predictors., 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 © 2024 Yu, Lin, Zhou, Yang and Hemelaar.)

Introduction: Global HIV infections due to HIV-1 recombinants are increasing and impede prevention and treatment efforts. Key populations suffer most new HIV infections, but their role in the spread of HIV-1 recombinants is unknown. We conducted a global analysis of the associations between key populations and HIV-1 recombinants., Methods: We searched PubMed, EMBASE, CINAHL, and Global Health for HIV-1 subtyping studies published from 1/1/1990 to 31/12/2015. Unpublished data was collected through a global survey. We included studies with HIV-1 subtyping data of key populations collected during 1990-2015. Key populations assessed were heterosexual people (HET), men who have sex with men (MSM), people who inject drugs (PWID), vertical transmissions (VERT), commercial sex workers (CSW), and transfusion-associated infections (BLOOD). Logistic regression was used to determine associations of key populations with HIV-1 recombinants. Subgroup analyses were performed for circulating recombinant forms (CRFs), unique recombinant forms (URFs), regions, and time periods., Results: Eight hundred and eighty five datasets including 77,284 participants from 83 countries were included. Globally, PWID were associated with the greatest odds of recombinants and CRFs (OR 2.6 [95% CI 2.46-2.74] and 2.99 [2.83-3.16]), compared to HET. CSW were associated with increased odds of recombinants and URFs (1.59 [1.44-1.75] and 3.61 [3.15-4.13]). VERT and BLOOD were associated with decreased odds of recombinants (0.58 [0.54-0.63] and 0.43 [0.33-0.56]). MSM were associated with increased odds of recombinants in 2010-2015 (1.43 [1.35-1.51]). Subgroup analyses supported our main findings., Discussion: As PWID, CSW, and MSM are associated with HIV-1 recombinants, increased preventative measures and HIV-1 molecular surveillance are crucial within these key populations., Systematic Review Registration: PROSPERO [CRD42017067164]., 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 © 2023 Nchinda, Elangovan, Yun, Dickson-Tetteh, Kirtley, Hemelaar and WHO-UNAIDS Network for HIV Isolation and Characterisation.)