Long-term follow-up of cytokines and soluble cytokine receptors in peripheral blood of patients with juvenile rheumatoid arthritis

Plasma levels of interleukin-1 beta (IL-1 beta), IL-2, soluble IL-2 recepto r (sIL-2R), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and the p6 0 soluble TNF receptor (sTNFR) were repeatedly determined by enzyme-linked immunosorbent assays (ELISA) in 35 patients with different subtypes of juve nile rheumatoid arthritis (JRA) during an observation period of up to 36 mo nths. The data were related to conventional inflammatory parameters and dis ease activity. Patients with systemic disease showed the most pronounced el evations of plasma cytokines, followed by polyarticular and pauciarticular JRA. Soluble receptors sIL-2R and sTNFR were consistently elevated in patie nts of all JRA subtypes and indicated disease activity even in patients wit h normal C-reactive protein (CRP). In contrast, the determination of IL-1 b eta, IL-2, IL-8, and TNF-alpha revealed strikingly different individual pro files in patients of the same clinical subtype of JRA and irrespective of d isease activity. It is concluded that the determination of sIL-2R and sTNFR may be relevant for monitoring JRA, as they indicate disease activity also in cases with unaltered conventional inflammatory parameters. The differen t individual cytokine profiles of patients within identical subtypes of dis ease suggest JRA to be even more heterogeneous than hitherto assumed. The d ata should be considered in attempts to develop anticytokine strategies in the therapy of JRA.