RESUMO
<p><b>OBJECTIVE</b>To study the changes in serum cytokines levels in children with newly diagnosed active systemic juvenile idiopathic arthritis (SJIA) and to explore the role of cytokines in the development and progression of SJIA.</p><p><b>METHODS</b>Seventy-four pediatric patients with active SJIA between January 2010 and December 2013 were included in the study. Serum levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukine-10 (IL-10), tumor necrosis factor (TNF), and interferon gamma (IFN-γ) were measured by flow cytometry in these patients. The levels of cytokines were also determined in 202 healthy children as the control group. Routine laboratory parameters including white blood cell (WBC) count, percentage of neutrophils, hemoglobin level, platelet count, hypersensitive C-reactive protein (hs-CRP), and erythrocyte sedimentation rate (ESR) were monitored in the patient group.</p><p><b>RESULTS</b>The WBC count, percentage of neutrophils, hs-CRP, and ESR in 74 cases of SJIA were significantly above the normal range, their platelet counts were within the normal range, whereas hemoglobin levels were below the normal range. Compared with the control group, the patient group showed a significantly increased level of IL-6 (P<0.01) and significantly reduced levels of IL-4, IL-10, and TNF (P<0.01). However, there were no significant changes in serum levels of IL-2 and IFN-γ in the patient group (P>0.05). In SJIA children, IL-6 level, which was significantly elevated, was negatively correlated with hemoglobin level, which was significantly reduced (r=-0.244, P<0.05).</p><p><b>CONCLUSIONS</b>Serum level of IL-6 is significantly increased in children with SJIA, and it has a negative correlation with anemia.</p>