Spontaneous production of, and defective response to, interleukin-1 by peripheral blood mononuclear cells from patients with scleroderma.

Interleukin-1 (IL-1) is a monocyte derived factor that participates in immune regulation and in the regulation of fibroblast proliferation and collagen deposition. It therefore, seems particularly pertinent to study in scleroderma, a disorder of immune regulation where increased collagen deposition is a hallmark. The production of IL-1 by lipopolysaccharide stimulated monocytes from 18 untreated scleroderma patients was akin to that of their normal matched controls. However, the unstimulated monocytes from six of the 18 scleroderma patients released IL-1 activity spontaneously into their supernatants. All six patients with spontaneous IL-1 release had less than 5 years disease duration. The response to IL-1 by T lymphocytes from patients with scleroderma was low as compared to those from controls. The presence of spontaneous IL-1 production with decreased response to IL-1 in scleroderma may indicate an in vivo pre-activation of monocytes to produce this factor that might have a bearing in the pathogenesis of collagen deposition in scleroderma.