Rheumatoid factors (RFs) are autoantibodies with specificity against constant regions of the heavy chain in the IgG Fc fragment. RFs are detected in several systemic autoimmune conditions and in infectious diseases and can be present in healthy subjects. Their highest prevalence is reported in rheumatoid arthritis (RA), in Sjögren's syndrome (SS), and in mixed cryoglobulinemia. Originally detected by semi-quantitative agglutination techniques, RFs are now measured by more standardized quantitative analyses (nephelometry, enzyme-linked immunosorbent assay (ELISA)). There is evidence for a pathogenic role of RFs in favoring the immune-complex (IC)-mediated lesions both at the systemic level and locally in the synovial environment in the course of RA. Although there are formal classification criteria for RA according to the American College of Rheumatology, RFs are not a specific diagnostic tool for RA. However, the presence of high RF titers is predictive for developing RA in non-symptomatic subjects and titers are associated with a more aggressive and destructive course and with the occurrence of extra-articular manifestations in RA patients. Successful response to treatment with both classical disease-modifying anti-rheumatic drugs (DMARDs) and new agents is associated with a decrease in RF titers.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)