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.