INTERLEUKIN-10 INHIBITION OF THE PROGRESSION OF ESTABLISHED COLLAGEN-INDUCED ARTHRITIS

Objective. Interleukin-10 (IL-10) is a potent inhibitor of the proinfl ammatory cytokines, including tumor necrosis factor alpha and IL-1, wh ich are considered important in the pathogenesis of rheumatoid arthrit is (RA). The study was undertaken to establish whether IL-10 can ameli orate arthritis in the collagen-induced arthritis (CIA) model of RA. M ethods. DBA/1 mice were immunized with bovine type II collagen in adju vant, and treated daily after disease onset with recombinant murine IL -10 or with saline as a control. Mice were monitored for paw swelling and clinical score. Histologic analysis was also performed. Results. I L-10 treatment of established CIA inhibited paw swelling (P < 0.0001), as well as disease progression as defined by clinical score (P < 0.00 02). Cartilage destruction, as assessed histologically, was reduced in IL-10-treated mice compared with controls (P < 0.01). Conclusion. IL- 10 suppresses established CIA, probably by inhibiting proinflammatory cytokine production. Our results, taken together with previously repor ted findings, indicate a potential therapeutic role for IL-10 in RA.