IL-1RA in refractory systemic lupus erythematosus.

There is evidence from animal and human studies that IL-1 might play an important role in the development and maintainence of inflammation in systemic lupus erythemathosus (SLE). We hypothesized that, in SLE, there might be a relative deficiency in the physiologic antagonist of IL-1, IL-1 receptor antagonist (IL-1RA). We therefore treated three patients with active SLE in whom conventional therapy has failed with the human IL-1RA, Anakinra. In two of the three patients there was a transient effect on muscle pain and/or polyarthritis. In one patient with lupus myositis there was no effect at all. The therapy was well tolerated and the only significant side effect was a transient drop in complement levels (C3 and C4) without clinical or laboratory signs of increased SLE activity in all three patients.