A novel paradigm in the clinical context of rheumatoid arthritis: role of Tfh and Th17 Cells in autoimmunity

Abstract

Abstract Introduction Rheumatoid Arthritis (RA) is an autoimmune disease characterized by chronic inflammation of synovium causing progressive joint destruction. Recently, T follicular helper (Tfh) cells and Th17 cells have emerged as novel T cell subsets controlling autoimmunity. Identifying their roles may break the traditional Th1/Th2 axis dichotomy and bridge knowledge gap of T cell lineages on RA immunopathogenesis. We examined the frequency of circulating Tfh (cTfh) and cTh17 cells in RA patients, and investigated their correlation with disease activity, autoantibody level, and inflammation. Methods Peripheral blood was collected from 51 RA patients and healthy donors. RA patients were divided into remission (<2.6) and active groups (>2.6) based on disease activity score (DAS-28). Clinic parameters including Rheumatoid Factor (RF), Anti-CCP, ESR and CRP were obtained. The frequency of cTfh, cTh17 cells, and plasmablasts were measured by flow cytometry. Correlation of the frequency of cTfh and cTh17 cells with DAS-28, plasmablasts, and clinic parameters were statistically determined. Results Both cTfh and cTh17 cells were significantly increased in RA patients, expecially in active patients comparing to healthy donors (p<0.05). The frequency of cTfh cells correlated with the percentage of plasmablasts and the level of pathogenic anti-CCP antibody, whereas the frequency of cTh17 cells correlated with serum level of RF and CRP as well as DAS-28. Conclusions Tfh cells may contribute to B cell differentiation and autoantibody production, while Th17 cells may involve in the inflamation and pathogenesis of RA. Thus, disrupting the signals provided by Tfh and Th17 cells may offer new therapeutic stategies for active RA patients.