The beneficial effect of total glucosides of paeony on psoriatic arthritis links to circulating Tregs and Th1 cell function.

ABSTRACT

Total glycosides of peony (TGP) is a natural immuno-modulatory drug extracted from traditional Chinese herb peony. It has been approved by State Food and Drug Administration for the treatment of rheumatoid arthritis. However, data of TGP effect on psoriatic arthritis (PsA) is still scarce. In this study, 19 patients with PsA received 12-week treatment of TGP, and clinical efficacy in joint manifestations was evaluated by DAS28 at weeks 0, 4, 8 and 12. Peripheral percentages of Tregs, Th1, Th2 and NK cells were analyzed, and serum Th1-type cytokines (IL-12, IFN-γ and TNF-α), Th2-type cytokines (IL-4, IL-5 and IL-10) as well as pro-inflammatory factors (IL-2, IL-6 and IL-8) were concomitantly examined. Six patients (32%) exhibited ≥25% decrease of DAS28 (responders). Interestingly, all responders displayed a continuous decrease in Treg and Th1 numbers during TGP treatment, concomitant with significant decreases in Th1-type cytokine levels. Serum IL-6 also showed a significant decline in responders. Non-responders lacked these sequential alterations. Thus, TGP merits further consideration as a promising therapeutic option for PsA. The result indicated that recovery of Tregs and Th1 may serve as prognostic markers to assess responsiveness to TGP treatment in PsA.