Interleukin-1 potentiates the development of collagen-induced arthritis in mice.

1. The subcutaneous administration of recombinant human interleukin-1 beta (rhIL-1 beta) was found to induce an increased incidence and earlier onset of collagen-induced arthritis in mice. 2. The rhIL-1 beta had different effects, depending on when it was administered after collagen-immunization. 3. The effect of rhIL-1 beta may be due, in part, to augmentation of the immune response to type II collagen. 4. Interleukin-1-accelerated, collagen-induced arthritis will provide a useful model for investigating the role of interleukin-1 in the regulation of arthritic diseases, and the development of anti-arthritic therapeutics.