[Clinical evaluation of serum cytokine from patients with collagen diseases].

PURPOSE: Systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) are characterized by an imbalance of cytokine production. To clarify the relationship between the profile of cytokines and the pathophysiology of systemic autoimmune diseases, we estimated the cytokine levels in sera from patients with several systemic autoimmune diseases.

METHOD: Serum cytokine levels in patients with unclassified connective tissue diseases were measured using ultrasensitive specific enzyme-linked immunosorbent assay (ELISA).

RESULT: These patients were diagnosed using the established category by further examinations within a 2-year period. Sera from patients with SLE contained higher titers of IL-10, and equal levels of IFN gamma and TNF alpha compared with those of normal controls. Patients with progressive systemic sclerosis (PSS) showed lower titers of IL-10 and higher titers of IFN gamma and TNF alpha in their sera than those of healthy controls. Seronegative rheumatoid arthritis (snRA) patients had a higher amount of IL-10 and TNF alpha, equivalent level of IFN gamma in their sera compared to those of controls. Moreover, patients with Sjögren's syndrome (SS) showed higher titers of IL-10 and TNF alpha, and an equivalent level of IFN gamma in their sera compared to healthy volunteers.

CONCLUSION

Based on these findings, for the differential diagnosis of patients with systemic autoimmune diseases such as SLE, PSS, snRA and SS, it may be useful to measure the levels of cytokines such as IL-10, IFN gamma, and TNF alpha in their sera.