Abstract
OBJECTIVE: The role of the cytokine interleukin 15 (IL-15) in rheumatic disease is unclear. We examined serum levels of IL-15 in patients with various rheumatic diseases. METHODS: Serum levels of IL-15 were determined by sandwich ELISA. RESULTS: Serum levels of IL-15 were significantly increased in patients with polymyositis/dermatomyositis, polyarteritis nodosa, and systemic sclerosis; and significantly increased as well in disease complicated by interstitial pneumonitis (IP), hemophagocytic syndrome (HPS), and/or vasculitis. Patients with serum IL-15 levels < or = 5 pg/ml showed significantly high rates of survival. CONCLUSION: IL-15 is related to the pathogenesis of IP, HPS, and/or vasculitis. Serum IL-15 level could possibly be used as a marker of prognosis.
