Objective: The co-occurrence of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) positivity in rheumatoid arthritis (RA) is well described. However, the mechanisms underlying the potential interaction between these 2 distinct autoantibodies have not been well defined. The aim of this study was to evaluate the epidemiologic and molecular interaction of ACPAs and RF and its association with both disease activity and measures of RA-associated inflammation.
Methods: In a cohort of 1,488 US veterans with RA, measures of disease activity and serum levels of cytokines and multiplex ACPAs were compared between the following groups of patients: double-negative (anti-cyclic citrullinated peptide [anti-CCP]-/RF-), anti-CCP+/RF-, anti-CCP-/RF+, or double-positive (anti-CCP+/RF+). Additional studies were performed using an in vitro immune complex (IC) stimulation assay in which macrophages were incubated with ACPA ICs in the presence or absence of monoclonal IgM-RF, and tumor necrosis factor α production measured as a readout of macrophage activation.
Results: Compared with the double-negative subgroup (as well as each single-positive subgroup), the double-positive subgroup exhibited higher disease activity as well as higher levels of C-reactive protein and inflammatory cytokines (all P < 0.001). In vitro stimulation of macrophages by ACPA ICs increased cytokine production, and the addition of monoclonal IgM-RF significantly increased macrophage tumor necrosis factor α production (P = 0.003 versus ACPA ICs alone).
Conclusion: The combined presence of ACPAs and IgM-RF mediates increased proinflammatory cytokine production in vitro and is associated with increased systemic inflammation and disease activity in RA. Our data suggest that IgM-RF enhances the capacity of ACPA ICs to stimulate macrophage cytokine production, thereby providing a mechanistic link by which RF enhances the pathogenicity of ACPA ICs in RA.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994896 | PMC |
http://dx.doi.org/10.1002/art.38307 | DOI Listing |
Immunology
December 2021
Centre for Inflammation Research, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh, UK.
Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease without known cure that primarily affects synovial joints. RA has a prevalence of approximately 1% of the population worldwide. A vicious circle between two critical immune cell types, B cells and neutrophils, develops and promotes disease.
View Article and Find Full Text PDFClin Immunol
March 2020
Division of Immunology and Rheumatology, Stanford University, Stanford, CA, United States of America; VA Palo Alto Health Care System, Palo Alto, CA, United States of America. Electronic address:
Arthritis Rheumatol
April 2014
VA Palo Alto Health Care System, Palo Alto, California, and Stanford University School of Medicine, Stanford, California.
Objective: The co-occurrence of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) positivity in rheumatoid arthritis (RA) is well described. However, the mechanisms underlying the potential interaction between these 2 distinct autoantibodies have not been well defined. The aim of this study was to evaluate the epidemiologic and molecular interaction of ACPAs and RF and its association with both disease activity and measures of RA-associated inflammation.
View Article and Find Full Text PDFArthritis Rheum
January 2011
Stanford University School of Medicine, Stanford, California, USA.
Objective: Rheumatoid arthritis (RA) is associated with the presence of anti-citrullinated protein antibodies (ACPAs). Nearly two-thirds of patients with ACPA-positive RA have immune complexes that contain citrullinated fibrinogen, and these citrullinated fibrinogen-containing immune complexes (cFb-IC) can exacerbate disease in murine models of RA; however, the exact role of such ACPA ICs in RA pathogenesis has remained elusive. We undertook the present study to investigate a novel mechanism by which ACPAs specifically targeting citrullinated fibrinogen may directly stimulate macrophage tumor necrosis factor (TNF) production.
View Article and Find Full Text PDFArthritis Rheum
March 2008
Unité Mixte de Recherche 5165 CNRS-Université Toulouse III, Institut Fédératif de Recherche 30 (IFR30) Toulouse, France.
Objective: Macrophage-derived tumor necrosis factor alpha (TNFalpha) is a dominant mediator of synovitis in rheumatoid arthritis (RA). This study was undertaken to assess whether and how immune complexes (ICs) formed by the interaction of disease-specific autoantibodies to citrullinated proteins (ACPAs) with their main synovial target antigen, citrullinated fibrin, contribute to TNFalpha production by macrophages.
Methods: An in vitro human model was developed in which monocyte-derived macrophages were stimulated with ACPA-containing ICs that were generated by capturing ACPAs from RA sera on immobilized citrullinated fibrinogen.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!