AUTOANTIBODIES IN THE PATHOGENESIS OF RHEUMATOID ARTHRITIS: DIAGNOSTIC AND PROGNOSTIC SIGNIFICANCE OF RHEUMATOID FACTOR AND ANTI-CCP

Abstract

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by symmetric erosive polyarthritis and, in most patients, the production of disease-specific autoantibodies. This narrative review synthesizes current evidence on the pathogenic role of rheumatoid factor (RF) and anti-citrullinated protein antibodies (anti-CCP, also termed ACPA) in RA, drawing on the 2010 ACR/EULAR classification criteria and the 2022 and 2025 EULAR recommendations for the management of RA. Contemporary evidence indicates that autoantibody production is not merely a diagnostic marker but an active driver of disease: gene-environment interactions, including the HLA-DRB1 shared epitope and cigarette smoking, promote peptidylarginine deiminase-mediated citrullination of self-proteins at mucosal surfaces, triggering a break in immune tolerance and the generation of high-affinity anti-CCP antibodies and RF years before the onset of clinically apparent synovitis. Once formed, these autoantibodies create immune complexes that activate complement and Fcγ receptors, drive synovial macrophage and fibroblast cytokine release, and, in the case of anti-CCP, bind directly to citrullinated vimentin on osteoclast precursors to stimulate bone resorption independent of inflammation. Anti-CCP offers substantially higher specificity than RF (approximately 95–98% versus 60–80%) at comparable sensitivity, and seropositivity — particularly double positivity for RF and anti-CCP — predicts a more erosive disease course, greater risk of extra-articular manifestations, and a treatment response profile that favors early, aggressive intervention. A mechanism-based understanding of RF and anti-CCP, combined with early classification and individualized, biomarker-informed treatment, is central to limiting irreversible joint damage and improving long-term outcomes, including within the healthcare system of Uzbekistan.