Search

Rheumatoid arthritis (RA) is a complex immune-mediated inflammatory disorder in which patients suffer from inflammatory-erosive arthritis. Recent advances on histopathology heterogeneity of RA synovial tissue revealed three distinct phenotypes based on cellular composition (pauci-immune, diffuse and lymphoid), suggesting that distinct etiologies warrant specific targeted therapy which motivates a need for cost effective phenotyping tools in preclinical and clinical settings. To this end, we developed an automated multi-scale computational pathotyping (AMSCP) pipeline for both human and mouse synovial tissue with two distinct components that can be leveraged together or independently: (1) segmentation of different tissue types to characterize tissue-level changes, and (2) cell type classification within each tissue compartment that assesses change across disease states. Here, we demonstrate the efficacy, efficiency, and robustness of the AMSCP pipeline as well as the ability to discover novel phenotypes. Taken together, we find AMSCP to be a valuable cost-effective method for both pre-clinical and clinical research. Automated pathotyping of synovial tissue in arthritis is a major unmet need. Here, the authors develop and demonstrate the efficacy of an automated tissue and cellular pathotyping tool for inflammatory arthritis. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is an autoimmune disease involving antigen-specific T and B cells. Here, we perform single-cell RNA and repertoire sequencing on paired synovial tissue and blood samples from 12 seropositive RA patients. We identify clonally expanded CD4 + T cells, including CCL5+ cells and T peripheral helper (Tph) cells, which show a prominent transcriptomic signature of recent activation and effector function. CD8 + T cells show higher oligoclonality than CD4 + T cells, with the largest synovial clones enriched in GZMK+ cells. CD8 + T cells with possibly virus-reactive TCRs are distributed across transcriptomic clusters. In the B cell compartment, NR4A1+ activated B cells, and plasma cells are enriched in the synovium and demonstrate substantial clonal expansion. We identify synovial plasma cells that share BCRs with synovial ABC, memory, and activated B cells. Receptor-ligand analysis predicted IFNG and TNFRSF members as mediators of synovial Tph-B cell interactions. Together, these results reveal clonal relationships between functionally distinct lymphocyte populations that infiltrate the synovium of patients with RA. Activated B cells and T cells accumulate within joints of patients with rheumatoid arthritis. Here, the authors use single-cell transcriptome and repertoire profiling to identify clonally expanded synovial B cells and T cells and define their phenotypes and predicted cell-cell interactions. [ABSTRACT FROM AUTHOR]

Synovial tissue inflammation is a hallmark of rheumatoid arthritis (RA). Recent work has identified prominent pathogenic cell states in inflamed RA synovial tissue, such as T peripheral helper cells; however, the epigenetic regulation of these states has yet to be defined. Here, we examine genome-wide open chromatin at single-cell resolution in 30 synovial tissue samples, including 12 samples with transcriptional data in multimodal experiments. We identify 24 chromatin classes and predict their associated transcription factors, including a CD8 + GZMK+ class associated with EOMES and a lining fibroblast class associated with AP-1. By integrating with an RA tissue transcriptional atlas, we propose that these chromatin classes represent 'superstates' corresponding to multiple transcriptional cell states. Finally, we demonstrate the utility of this RA tissue chromatin atlas through the associations between disease phenotypes and chromatin class abundance, as well as the nomination of classes mediating the effects of putatively causal RA genetic variants. The epigenetic changes underlying the heterogeneity of RA disease presentation have been the subject of intense scrutiny. In this study, the authors use multiple single-cell sequencing datasets to define 'chromatin superstates' in patients with RA, which associate with distinct transcription factors and disease phenotypes. [ABSTRACT FROM AUTHOR]

The progression of osteoarthritis of the hip to its end stage and ultimately to total hip arthroplasty (THA) is complex; the multifactorial pathophysiology involves myriad collaborating tissues in and around the diseased joint. We have named the heightened state of periarticular muscle inflammation at the time of surgery "muscle inflammation susceptibility" (MuIS) because it is distinct from systemic inflammation. In this review article, we discuss how MuIS and heightened atrophy-associated signaling in the periarticular skeletal muscles may contribute to reduced muscle mass, impaired muscle quality (ie, through fibrosis), and a muscle microenvironment that challenges regenerative capacity and thus functional recovery from THA. We also review directions for future research that should advance understanding of the key determinants of precision for optimized success of THA for each individual. [ABSTRACT FROM AUTHOR]

Introduction: While cystic fibrosis (CF) lung disease is characterized by persistent inflammation and infections and chronic inflammatory diseases are often accompanied by autoimmunity, autoimmune reactivity in CF has not been studied in depth. Methods: In this work we undertook an unbiased approach to explore the systemic autoantibody repertoire in CF using autoantibody microarrays. Results and discussion: Our results show higher levels of several new autoantibodies in the blood of people with CF (PwCF) compared to control subjects. Some of these are IgA autoantibodies targeting neutrophil components or autoantigens linked to neutrophil-mediated tissue damage in CF. We also found that people with CF with higher systemic IgM autoantibody levels have lower prevalence of S. aureus infection. On the other hand, IgM autoantibody levels in S. aureus-infected PwCF correlate with lung disease severity. Diabetic PwCF have significantly higher levels of IgA autoantibodies in their circulation compared to nondiabetic PwCF and several of their IgM autoantibodies associate with worse lung disease. In contrast, in nondiabetic PwCF blood levels of IgA autoantibodies correlate with lung disease. We have also identified other autoantibodies in CF that associate with P. aeruginosa airway infection. In summary, we have identified several new autoantibodies and associations of autoantibody signatures with specific clinical features in CF. [ABSTRACT FROM AUTHOR]

The ability of individuals with end-stage osteoarthritis (OA) to functionally recover from total joint arthroplasty is highly inconsistent. The molecular mechanisms driving this heterogeneity have yet to be elucidated. Furthermore, OA disproportionately impacts females, suggesting a need for identifying female-specific therapeutic targets. We profiled the skeletal muscle transcriptome in females with end-stage OA (n = 20) undergoing total knee or hip arthroplasty using RNA-Seq. Single-gene differential expression (DE) analyses tested for DE genes between skeletal muscle overlaying the surgical (SX) joint and muscle from the contralateral (CTRL) leg. Network analyses were performed using Pathway-Level Information ExtractoR (PLIER) to summarize genes into latent variables (LVs), i.e., gene circuits, and link them to biological pathways. LV differences in SX versus CTRL muscle and across sources of muscle tissue (vastus medialis, vastus lateralis, or tensor fascia latae) were determined with ANOVA. Linear models tested for associations between LVs and muscle phenotype on the SX side (inflammation, function, and integrity). DE analysis revealed 360 DE genes (jLog2 fold-differencej ≥ 1, FDR ≤ 0.05) between the SX and CTRL limbs, many associated with inflammation and lipid metabolism. PLIER analyses revealed circuits associated with protein degradation and fibro-adipogenic cell gene expression. Muscle inflammation and function were linked to an LV associated with endothelial cell gene expression highlighting a potential regulatory role of endothelial cells within skeletal muscle. These findings may provide insight into potential therapeutic targets to improve OA rehabilitation before and/or following total joint replacement. [ABSTRACT FROM AUTHOR]

The immune and coagulation systems are both implicated in the pathogenesis of rheumatoid arthritis (RA). Plasma carboxypeptidase B (CPB), which is activated by the thrombin/thrombomodulin complex, plays a procoagulant role during fibrin clot formation. However, an antiinflammatory role for CPB is suggested by the recent observation that CPB can cleave proinflammatory mediators, such as C5a, bradykinin, and osteopontin. Here, we show that CPB plays a central role in downregulating C5a-mediated inflammatory responses in autoimmune arthritis. CPB deficiency exacerbated inflammatory arthritis in a mouse model of RA, and cleavage of C5a by CPB suppressed the ability of C5a to recruit immune cells in vivo. In human patients with RA, genotyping of nonsynonymous SNPs in the CPB-encoding gene revealed that the allele encoding a CPB variant with longer half-life was associated with a lower risk of developing radiographically severe RA. Functionally, this CPB variant was more effective at abrogating the proinflammatory properties of C5a. Additionally, expression of both CPB and C5a in synovial fluid was higher in patients with RA than in those with osteoarthritis. These findings suggest that CPB plays a critical role in dampening local, C5a-mediated inflammation and represents a molecular link between inflammation and coagulation in autoimmune arthritis., Introduction Rheumatoid arthritis (RA) is an inflammatory arthritis characterized by activation of both inflammatory and coagulation pathways (1). Fibrin deposition, the culmination of the coagulation cascade, is a hallmark of [...]

Many individuals with end-stage osteoarthritis (OA) undergo elective total hip/knee arthroplasty (THA/TKA) to relieve pain, improve mobility and quality of life. However, -30% suffer long-term mobility impairment following surgery. This may be in part due to muscle inflammation susceptibility (MuISþ), an overt proinflammatory pathology localized to skeletal muscle surrounding the diseased joint, present in some patients with TKA/THA. We interrogated the hypothesis that MuISþ status results in a perturbed perioperative gene expression profile and decreases skeletal muscle integrity in patients with end-stage OA. Samples were leveraged from the two-site, randomized, controlled trial R01HD084124, NCT02628795. Participants were dichotomized based on surgical (SX) muscle gene expression of TNFRSF1A (TNF-aR). MuISþ/° samples were probed for gene expression and fibrosis. Paired and independent twotailed t tests were used to determine differences between contralateral (CTRL) and surgical (SX) limbs and between-subject comparisons, respectively. Significance was declared at P < 0.05. Seventy participants (26M/44F; mean age 62.41 ± 8.86 yr; mean body mass index 31.10 ± 4.91 kg/m2) undergoing THA/TKA were clustered as MuISþ (n = 24) or MuIS° (n = 46). Lower skeletal muscle integrity (greater fibrosis) exists on the SX versus CTRL limb (P < 0.001). Furthermore, MuISþ versus MuIS° muscle exhibited higher proinflammatory (IL-6R and TNF-a) and catabolic (TRIM63) gene expression (P < 0.001, P = 0.004, and 0.024 respectively), with a trend for greater fibrosis (P = 0.087). Patients with MuISþ exhibit more inflammation and catabolic gene expression in skeletal muscle of the SX limb, accompanied by decreased skeletal muscle integrity (Trend). This highlights the impact of MuISþ status emphasizing the potential value of perioperative MuIS assessment to inform optimal postsurgical care. NEW & NOTEWORTHY This study assessed the skeletal muscle molecular characteristics associated with end-stage osteoarthritis and refined an important phenotype, in some patients, termed muscle inflammation susceptibility (MuISþ) that may be an important consideration following surgery. Furthermore, we provide evidence of differential inflammatory and catabolic gene expression between the contralateral and surgical limbs along with differences between the skeletal muscle surrounding the diseased hip versus knee joints. [ABSTRACT FROM AUTHOR]

Background: The safety and effectiveness of live virus vaccines, such as the varicella-zoster vaccine, are unknown in patients with inflammatory diseases receiving immunomodulatory therapy such as tumor necrosis factor inhibitors (TNFis).Objective: To evaluate the safety and immunogenicity of the live attenuated zoster vaccine (ZVL) in patients receiving TNFis.Design: Randomized, blinded, placebo-controlled trial. (ClinicalTrials.gov: NCT02538341).Setting: Academic and community-based rheumatology, gastroenterology, and dermatology practices.Patients: Adults aged 50 years or older receiving TNFis for any indication.Intervention: Random assignment to ZVL versus placebo.Measurements: Glycoprotein enzyme-linked immunosorbent assay (gpELISA) and enzyme-linked immunosorbent spot (ELISpot) from serum and peripheral blood mononuclear cells measured at baseline and 6 weeks after vaccination. Suspected varicella infection or herpes zoster was clinically assessed using digital photographs and polymerase chain reaction on vesicular fluid.Results: Between March 2015 and December 2018, 617 participants were randomly assigned in a 1:1 ratio to receive ZVL (n = 310) or placebo (n = 307) at 33 centers. Mean age was 62.7 years (SD, 7.5); 66.1% of participants were female, 90% were White, 8.2% were Black, and 5.9% were Hispanic. The most common TNFi indications were rheumatoid arthritis (57.6%) and psoriatic arthritis (24.1%); TNFi medications were adalimumab (32.7%), infliximab (31.3%), etanercept (21.2%), golimumab (9.1%), and certolizumab (5.7%). Concomitant therapies included methotrexate (48.0%) and oral glucocorticoids (10.5%). Through week 6, no cases of confirmed varicella infection were found; cumulative incidence of varicella infection or shingles was 0.0% (95% CI, 0.0% to 1.2%). At 6 weeks, compared with baseline, the mean increases in geometric mean fold rise as measured by gpELISA and ELISpot were 1.33 percentage points (CI, 1.17 to 1.51 percentage points) and 1.39 percentage points (CI, 1.07 to 1.82 percentage points), respectively.Limitation: Potentially limited generalizability to patients receiving other types of immunomodulators.Conclusion: This trial informs safety concerns related to use of live virus vaccines in patients receiving biologics.Primary Funding Source: The National Institute of Arthritis and Musculoskeletal and Skin Diseases and the American College of Rheumatology. [ABSTRACT FROM AUTHOR]

Pancreatic beta-cell death is a major factor in the pathogenesis of type 1 diabetes (T1D), but straightforward methods to measure beta-cell loss in humans are lacking, underlining the need for novel biomarkers. Using studies in INS-1 cells, human islets, diabetic mice, and serum samples of subjects with T1D at different stages, we have identified serum miR-204 as an early biomarker of T1D-associated beta-cell loss in humans. MiR-204 is a highly enriched microRNA in human beta-cells, and we found that it is released from dying beta-cells and detectable in human serum. We further discovered that serum miR-204 was elevated in children and adults with T1D and in autoantibody-positive at-risk subjects but not in type 2 diabetes or other autoimmune diseases and was inversely correlated with remaining beta-cell function in recent-onset T1D. Thus, serum miR-204 may provide a much needed novel approach to assess early T1D-associated human beta-cell loss even before onset of overt disease. [ABSTRACT FROM AUTHOR]

Objective: Genetic risk scores (GRS) have been developed that differentiate individuals with type 1 diabetes from those with other forms of diabetes and are starting to be used for population screening; however, most studies were conducted in European-ancestry populations. This study identifies novel genetic variants associated with type 1 diabetes risk in African-ancestry participants and develops an African-specific GRS.Research Design and Methods: We generated single nucleotide polymorphism (SNP) data with the ImmunoChip on 1,021 African-ancestry participants with type 1 diabetes and 2,928 control participants. HLA class I and class II alleles were imputed using SNP2HLA. Logistic regression models were used to identify genome-wide significant (P < 5.0 × 10-8) SNPs associated with type 1 diabetes in the African-ancestry samples and validate SNPs associated with risk in known European-ancestry loci (P < 2.79 × 10-5).Results: African-specific (HLA-DQA1*03:01-HLA-DQB1*02:01) and known European-ancestry HLA haplotypes (HLA-DRB1*03:01-HLA-DQA1*05:01-HLA-DQB1*02:01, HLA-DRB1*04:01-HLA-DQA1*03:01-HLA-DQB1*03:02) were significantly associated with type 1 diabetes risk. Among European-ancestry defined non-HLA risk loci, six risk loci were significantly associated with type 1 diabetes in subjects of African ancestry. An African-specific GRS provided strong prediction of type 1 diabetes risk (area under the curve 0.871), performing significantly better than a European-based GRS and two polygenic risk scores in independent discovery and validation cohorts.Conclusions: Genetic risk of type 1 diabetes includes ancestry-specific, disease-associated variants. The GRS developed here provides improved prediction of type 1 diabetes in African-ancestry subjects and a means to identify groups of individuals who would benefit from immune monitoring for early detection of islet autoimmunity. [ABSTRACT FROM AUTHOR]

Objective: Currently, there are no reliable biomarkers for predicting therapeutic response in patients with rheumatoid arthritis (RA). The synovium may unlock critical information for determining efficacy, since a reduction in the numbers of sublining synovial macrophages remains the most reproducible biomarker. Thus, a clinically actionable method for the collection of synovial tissue, which can be analyzed using high‐throughput strategies, must become a reality. This study was undertaken to assess the feasibility of utilizing synovial biopsies as a precision medicine‐based approach for patients with RA. Methods: Rheumatologists at 6 US academic sites were trained in minimally invasive ultrasound‐guided synovial tissue biopsy. Biopsy specimens obtained from patients with RA and synovial tissue from patients with osteoarthritis (OA) were subjected to histologic analysis, fluorescence‐activated cell sorting, and RNA sequencing (RNA‐seq). An optimized protocol for digesting synovial tissue was developed to generate high‐quality RNA‐seq libraries from isolated macrophage populations. Associations were determined between macrophage transcriptional profiles and clinical parameters in RA patients. Results: Patients with RA reported minimal adverse effects in response to synovial biopsy. Comparable RNA quality was observed from synovial tissue and isolated macrophages between patients with RA and patients with OA. Whole tissue samples from patients with RA demonstrated a high degree of transcriptional heterogeneity. In contrast, the transcriptional profile of isolated RA synovial macrophages highlighted different subpopulations of patients and identified 6 novel transcriptional modules that were associated with disease activity and therapy. Conclusion: Performance of synovial tissue biopsies by rheumatologists in the US is feasible and generates high‐quality samples for research. Through the use of cutting‐edge technologies to analyze synovial biopsy specimens in conjunction with corresponding clinical information, a precision medicine–based approach for patients with RA is attainable. [ABSTRACT FROM AUTHOR]

The article reflects on biologic therapy. Topics discussed include immunogenicity and scientific aspects of manufacturing; extrapolation of indications, switching, and substitution and interchangeability; and transitioning and changing to biosimilar. Also being discussed is the economics of biosimilars and patient access.

Background: There is abundant evidence that low socioeconomic status (SES) is associated with worse health outcomes among people with Rheumatoid Arthritis (RA); however, the influence of socioeconomic disadvantage in early life has yet to be studied within that population.Methods: Data originated from the cross-sectional arm of the Consortium Evaluation of African-Americans with Rheumatoid Arthritis (CLEAR II), which recruited African-Americans with RA from six sites in the Southeastern United States. We used linear regression models to evaluate associations of parental homeownership status and educational level at participant time of birth with participant-reported fatigue (Visual Analog scale, cm), pain (Visual Analog scale, cm), disability (Health Assessment Questionnaire) and helplessness (Rheumatology Attitudes Index), independently of participant homeownership status and educational level. Models included random effects to account for intra-site correlations, and were adjusted for variables identified using backward selection, from: age, disease-duration, sex, medication use, body-mass index, smoking history.Results: Our sample included 516 CLEAR II participants with full data on demographics and covariates. 89% of participants were women, the mean age was 54.7 years and mean disease duration was 10.8 years. In age adjusted models, parental non-homeownership was associated with greater fatigue (β = 0.75, 95% CI = 0.36-1.14), disability (β = 0.12, 95% CI = 0.04-0.19) and helplessness (β = 0.12, 95% CI = 0.03-0.21), independently of participant homeownership and education; parental education had a further small influence on self-reported fatigue (β = 0.20, 95% CI = 0.15-0.24).Conclusions: Parental homeownership, and to a small extent parental education, had modest but meaningful relationships with self-reported health among CLEAR II participants. [ABSTRACT FROM AUTHOR]

Background: Reverse transcription quantitative PCR (RT-qPCR) is considered the gold standard for quantifying relative gene expression. Normalization of RT-qPCR data is commonly achieved by subtracting the Ct values of the internal reference genes from the Ct values of the target genes to obtain ΔCt. ΔCt values are then used to derive ΔΔCt when compared to a control group or to conduct further statistical analysis. Results: We examined two rheumatoid arthritis RT-qPCR low density array datasets and found that this normalization method introduces substantial bias due to differences in PCR amplification efficiency among genes. This bias results in undesirable correlations between target genes and reference genes, which affect the estimation of fold changes and the tests for differentially expressed genes. Similar biases were also found in multiple public mRNA and miRNA RT-qPCR array datasets we analysed. We propose to regress the Ct values of the target genes onto those of the reference genes to obtain regression coefficients, which are then used to adjust the reference gene Ct values before calculating ΔCt. Conclusions: The per-gene regression method effectively removes the ΔCt bias. This method can be applied to both low density RT-qPCR arrays and individual RT-qPCR assays. [ABSTRACT FROM AUTHOR]

The article presents information on a study which investigated the relationship between cigarette smoking and rheumatoid arthritis (RA) in African Americans, and whether the association is affected by the human leukocyte antigen (HLA)-DRB1 shared epitope (SE). A review of the related literature is presented. Variables investigated included smoking status, cumulative smoking exposure and SE status. It concludes that cigarette smoking causes both autoantibody-positive and autoantibody-negative RA in African Americans.

The article presents information on a study which determined whether the cumulative effects of the validated risk alleles for rheumatoid arthritis (RA) in Europeans also confer risk for RA in African Americans. A brief background on RA and its prevalence among Europeans and African Americans is presented. Methodology included the genotyping of 27 candidate single-nucleotide polymorphisms in 556 autoantibody-positive African Americans with RA and 791 healthy African American control group. It discusses the findings of the study.

OBJECTIVE: We previously observed the association of the co-occurrence of the HLA-DRB1 shared epitope (SE) and RANKL single-nucleotide polymorphisms (SNPs) with younger age at the onset of rheumatoid arthritis (RA) in 182 rheumatoid factor (RF)-positive European American patients with early-onset RA. The aim of this study was to fine-map the 48-kb RANKL region in the extended cohort of 210 European American RF-positive patients with early RA, to seek replication of RA-associated SNPs in additional RA cohorts of 501 European Americans and 298 African Americans, and to explore the functional consequences of RA-associated SNPs. METHODS: SNP genotyping was conducted using pyrosequencing or TaqMan polymerase chain reaction (PCR) assays. Associations of rs7984870 with RANKL expression in plasma, peripheral blood mononuclear cells, and isolated T cells were quantified using enzyme-linked immunosorbent assay and reverse transcription-PCR. Site-directed mutagenesis of rs7984870 within the 2-kb RANKL promoter was performed to drive the luciferase reporter gene in osteoblast and stromal cell lines. Interaction of DNA and protein was determined by electrophoretic mobility shift assay. RESULTS: A single promoter SNP, rs7984870, was consistently significantly associated with earlier age at the onset of RA in 3 independent seropositive (RF or anti-cyclic citrullinated peptide antibody) RA cohorts but not in seronegative RA patients. The C risk allele of rs7984870 conferred 2-fold higher plasma RANKL levels in RF-positive patients with RA, significantly elevated RANKL messenger RNA expression in activated normal T cells, and increased promoter activity after stimulation in vitro via differential binding to the transcription factor SOX5. CONCLUSION: The RANKL promoter allele that increased transcription levels upon stimulation might promote interaction between activated T cells and dendritic cells, predisposing to a younger age at the onset of RA in seropositive European American and African American patients. [ABSTRACT FROM AUTHOR]

The article details a study which examined the association between the functional RANKL polymorphism and younger age at the onset of rheumatoid arthritis (RA). The study included 210 European American radio frequency (RF)-positive patients with early RA. It concluded that RANKL promoter allele can promote interaction between activated T cells and dendritic cells that predisposes younger age at onset of RA in European Americans and African Americans.

OBJECTIVE: To examine the association between baseline bone mineral density (BMD) and radiographic damage at 3 years of disease duration in a longitudinal cohort of African Americans with recent-onset rheumatoid arthritis (RA). METHODS: African American RA patients with a disease duration of <2 years (n = 141) were included in the study. All patients underwent baseline BMD measurements (femoral neck and/or lumbar spine) using dual x-ray absorptiometry. T scores were calculated using normative data from the general population of African Americans. Patients were categorized as having osteopenia/osteoporosis (T score less than or equal to -1) or as being healthy. Hand and wrist radiographs, obtained at baseline and at 3 years of disease duration, were scored using the modified Sharp/van der Heijde method. The association between baseline BMD and total radiographic score at 3 years of disease was examined using multivariable negative binomial regression. RESULTS: At baseline, the mean age and the mean disease duration were 52.4 years and 14.8 months, respectively; 85.1% of the patients were women. The average total radiographic scores at baseline and at 3 years of disease were 2.4 and 5.7, respectively. In the final reduced multivariable model, adjusting for age, sex, anti-cyclic citrullinated peptide antibody positivity, and the presence of radiographic damage at baseline, the total radiographic score at 3 years disease in patients with osteopenia/osteoporosis of the femoral neck was twice that in patients with normal bone density, and the difference was statistically significant (P = 0.0084). No association between lumbar spine osteopenia/osteoporosis and radiographic score was found. CONCLUSION: Our findings suggest that reduced generalized BMD may be a predictor of future radiographic damage and support the hypothesis that radiographic damage and reduced generalized BMD in RA patients may share a common pathogenic mechanism. [ABSTRACT FROM AUTHOR]