Serum IL-4, IL-10 and IL-6 levels in inflammatory arthritis.

ABSTRACT

As the available in vitro and in vivo data suggest that interleukin (IL)-4 and IL-10 have immunosuppressive activity, our hypothesis was that serum IL-4 and IL-10 levels would correlate inversely with parameters of inflammation in patients with inflammatory arthritis. IL-4 was detected in the serum of 12 out of 140 patients with rheumatoid arthritis (RA), which was increased compared to the proportion found with patients with osteoarthritis (OA; P < 0.02). In addition, IL-4 was detected in the serum of 2 of 19 patients with systemic lupus erythematosus (SLE), 2 of 24 patients with psoriatic arthritis and 1 of 5 patients with Behçet's syndrome. No IL-4 was detected in patients with the following conditions OA (58 patients), gout (17 patients), ankylosing spondylitis (6 patients), Reiter's syndrome (6 patients), polymyalgia rheumatica (6 patients), temporal arteritis (5 patients) and scleroderma (3 patients). No IL-10 was detected in any of the sera tested. We discuss the possible relevance of these results to the regulation of the immune response evident in inflammatory arthritis.