ELEVATED CIRCULATING INTERLEUKIN-7 LEVELS IN PATIENTS WITH SYSTEMIC JUVENILE RHEUMATOID-ARTHRITIS

Objective. Since interleukin-7 (IL-7) has been shown to induce monocyt e production of IL-1, IL-6, IL-8, and tumor necrosis factor-alpha, we investigated plasma and synovial fluid levels of IL-7 in patients with juvenile rheumatoid arthritis (JRA). Methods. IL-7 levels were measur ed using an ELISA in 60 patients with JRA and in 25 patients with othe r rheumatic disorders (ORD). Results. In patients with systemic JRA, b ut not in patients with polyarticular or pauciarticular JRA or with OR D, plasma IL-7 levels were significantly higher (p <0.0001) than those of healthy controls. IL-7 was undetected in all synovial fluid tested . Among patients with systemic JRA, those with persistent systemic sym ptoms had IL-7 levels significantly higher (p <0.01) than those of pat ients in which systemic symptoms subsided. Conclusion. Plasma IL-7 lev els are elevated in patients with systemic JRA and are associated with the presence and severity of systemic symptoms,