Interleukin-1, interleukin-2, interleukin-4, interleukin-6, tumor necrosis factor alpha, and interferon-gamma levels in sera from patients with scleroderma.

OBJECTIVE. To determine whether interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-4, interferon-gamma (IFN gamma), IL-6, and tumor necrosis factor alpha (TNF alpha) are detected more frequently in sera from scleroderma patients than in sera from controls. METHODS. Serum concentrations of these cytokines were measured in 78 scleroderma patients and 73 controls, using enzyme-linked immunosorbent assay, radioimmunoassay, and bioassay techniques. RESULTS. IL-2, IL-4, and IL-6 were each detected more frequently in sera from scleroderma patients than in sera from controls. TNF alpha and IL-1 alpha were found with equal frequency in patient and control sera. IL-1 beta and IFN gamma were not detected in any sera. CONCLUSION. IL-2, IL-4, and IL-6 may be among the cytokines that contribute to the disease process in scleroderma patients. To our knowledge, this is the first report of elevated serum IL-4 levels in human disease.