Effects of infliximab on cytokines, myeloperoxidase, and soluble adhesion molecules in patients with juvenile idiopathic arthritis.

Objective: Infliximab is effective and well tolerated in the treatment of juvenile idiopathic arthritis (JIA). The aim of the present study was to measure circulating levels of inflammatory mediators in patients with JIA during treatment with infliximab.

Methods: Eight patients with active JIA refractory to standard treatments were treated with infliximab (3-4 mg/kg) at weeks 0, 2 and 6 and thereafter at approximately 6-week intervals up to 24 weeks.

Results: All patients (n = 8) responded to the treatment. By 6 weeks of treatment the number of active joints had reduced from 16+/-4 (mean+/-SEM) to 4+/-1 (p<0.01) and C-reactive protein (CRP) levels had fallen from 31+/-8 to 8+/-3 (p<0.001). Infliximab treatment also reduced the serum concentrations of interleukin-6 (IL-6), myeloperoxidase (MPO), and soluble adhesion molecules ICAM-1 (intercellular adhesion molecule-1), and E-selectin. Tumour necrosis factor-alpha (TNFalpha) levels tended to increase while the concentrations of endogenous TNF antagonists (sTNF-RI and sTNF-RII) reduced in most patients during treatment.

Conclusions: Infliximab reduced serum levels of IL-6, MPO and soluble adhesion molecules in JIA patients, producing a good clinical response to the treatment.