Interleukin‐1, Interleukin‐2, Interleukin‐4, Interleukin‐6, Tumor Necrosis Factor α, and Interferon‐γ Levels in Sera from Patients With Scleroderma

Objective. To determine whether interleukin‐lα (IL‐1α), IL‐1β, IL‐2, IL‐4, interferon‐γ (IFNγ), IL‐6, and tumor necrosis factor α (TNFα) 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. TNFα and IL‐1α were found with equal frequency in patient and control sera. IL‐1β and IFNγ 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.