The impact of conventional DMARD and biological therapies on CD4+ cell subsets in rheumatoid arthritis: a follow-up study

Abstract

Rheumatoid arthritis (RA) is an autoimmune disease characterized by abnormal prevalence of Th1, Th2, Th17, and regulatory (Treg) subsets. Some data suggest that these subsets are influenced by anti-RA agents. Follow-up studies monitoring T cell phenotype in response to therapy are limited. We investigated the alteration of CD4+ T cell subset distribution after the initiation of disease-modifying antirheumatic drug (DMARD) (with glucocorticosteroid (GCS) and methotrexate (MTX)) and anti-TNFα therapy. We enrolled 19 treatment naive (early) RA patients and initiated GCS (in a dose of 16 mg/day for 4 weeks; then 8 mg/day). MTX, 10 mg/week, was started at week 4. We also enrolled 32 RA patients unresponsive to DMARD and initiated anti-TNFα therapy: adalimumab (ADA), 40 mg/2 weeks, n = 12; etanercept (ETA), 50 mg/weeks, n = 12; or infliximab (IFX) on week 0, 2, and 6, 3 mg/kg bw, n = 8. Blood was taken before and 4 and 8 weeks after the initiation of therapy. Ten volunteers served as controls. The T cell phenotype was assessed with flow cytometry. In early RA, Th1, Th2, and Th17 prevalence was higher, while Treg prevalence was lower than normal. GCS alone decreased Th2 prevalence. GCS + MTX decreased Th17 prevalence. Immune phenotype in unresponsive RA before anti-TNF therapy was as in early RA. Four and 8 weeks after initiating anti-TNF therapy, Th1 prevalence was higher than baseline in ETA or IFX, while it was stable in ADA groups. Th2 prevalence was higher than normal in ADA or IFX, while normalized in ETA group. In each group, Treg prevalence increased, while Th17 prevalence was at the baseline. The proinflammatory immune phenotype is normalized only under GCS + MTX combination in early RA. Anti-TNFα therapy exhibit marked effects on all the cell populations investigated (except Th17); some slight differences in this action exist between ADA, ETA, and IFX therapy.