Fox, David A.

Abstract Individuals who have serum elevations of anti-cyclic citrullinated protein (anti-CCP) antibodies are at risk for developing rheumatoid arthritis (RA), yet immunologic factors that lead to a transition from pre- to clinical RA remain unclear. Here, we used materials from anti-CCP antibody-positive individuals enrolled in a clinical trial that evaluated the efficacy of hydroxychloroquine to prevent clinical RA, and performed multi-modal single-cell profiling (transcriptome, surface proteins, T/B-cell receptor sequencing, and chromatin accessibility) on samples obtained at baseline and at RA onset in those who developed clinical RA (Converters) or follow-up point in matched Nonconverters. At both baseline and follow-up, Converters had expansions of peripheral helper T (Tph) cells and CD8 + T cells expressing GZMK and GZMB , along with elevated potentially autoreactive T-cell receptors in CD4 + T cells compared to Nonconverters. Induction of age-associated B cell signatures was observed in B cells of Converters prior to RA onset. Epigenetic profiling further identified chromatin accessibility changes in Converters over time, particularly within myeloid and NK cells. Lastly, predictive modeling using baseline immune features, including Tph cells, GZMK + XCL1 + CD8 + , and GZMB + CD57 + CD8 + T cells, together with clinical features such as anti-CCP3 levels, RF-positivity, and HLA shared epitope status, stratified RA risk and predicted time to onset. These findings define immune endotypes in pre-RA that could serve as targets for future preventive interventions and be used to stratify the risk of developing clinical RA in anti-CCP antibody-positive individuals.

Objective Individuals with serum elevations of anti–cyclic citrullinated peptide (anti‐CCP) antibodies are at increased risk for future rheumatoid arthritis (RA). No pharmacologic interventions have been approved for the prevention of RA in such at‐risk individuals. However, hydroxychloroquine (HCQ) is used without supporting clinical trial evidence. Methods In this phase 2 randomized trial, individuals at risk for RA with anti‐CCP3 ≥2 times the upper limit of normal (ULN) were assigned to receive HCQ or placebo for 12 months, with up to 24 months of postdrug follow‐up. The primary outcome was the development of clinical RA, as defined in the protocol, at 36 months. Secondary outcomes included safety, development of inflammatory arthritis (IA), and participant‐reported joint symptoms. Results Of 144 randomized participants, 71 were assigned to HCQ and 73 to placebo. In the modified intent‐to‐treat population, clinical RA occurred in 21 of 69 (30.4%) participants in the HCQ group and 24 of 73 (32.9%) in the placebo group. The risk of clinical RA at 36 months was 0.336 with HCQ and 0.394 with placebo (difference −0.058; 95% confidence interval −0.336 to 0.220; P = 0.52). Results for IA were similar. The occurrence and severity of joint symptoms were not observed to differ between groups. Adverse event incidence was similar between groups. Conclusion In this trial involving individuals with anti‐CCP3 levels ≥2 times the ULN, 12 months of HCQ did not prevent the development of clinical RA at 36 months. image

Context.— Misdiagnosis of antiphospholipid syndrome can occur owing to the wide diversity of antiphospholipid (aPL) assays and a lack of international calibrators and harmonized reference intervals. Objective.— To assess laboratory practices regarding reporting and establishing reference intervals for immunoglobulin (Ig) G/IgM anti-cardiolipin (aCL) and anti–beta-2 glycoprotein I (anti-β2GPI) assays. Design.— Supplemental questions related to reporting and establishing reference ranges for aPL assays were sent as part of the Antiphospholipid Antibody (ACL)-B 2019 College of American Pathologists (CAP) proficiency testing survey. The response rate and methods assessment details were determined, as well as qualitative and quantitative results for 3 test samples. Results.— The number of participants reporting results for IgG aCL (n = 489), IgM aCL (n = 476), IgG anti-β2GPI (n = 354), and IgM anti-β2GPI (n = 331) varied by antibody type. The enzyme-linked immunosorbent assay (ELISA) (up to 58.6%, 260 of 444) was the most used method; others included multiplex (from 18.9% to 23.9%), fluorescence enzyme immunoassay (14.4%–17.6%), and chemiluminescence immunoassay (6.5%–9.0%). More respondents reported quantitative than qualitative results, and manufacturer cutoff ranges were used by 92.9% and 94.2% of respondents for aCL and anti-β2GPI, respectively. Despite variation in the use of semiquantitative ranges, qualitative negative/positive reporting of the test samples achieved almost 100% consensus. Qualitative consensus was met in contrast to the wide range of quantitative results obtained for each analyte across different kits. Conclusions.— ELISA remains the most used method for detecting aPL antibodies, with most laboratories reporting quantitative results based on manufacturers' suggested reference ranges. The categorization of quantitative results as equivocal, weak positive, or positive for responders using kits from the same manufacturer was variable.

ObjectiveCurrently, 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.MethodsRheumatologists 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.ResultsPatients 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.ConclusionPerformance 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.