Abstract OBJECTIVE: Interleukin 6(IL-6) is an autocrine growth factor for mesangial cells.This study aimed to investigate the changes of IL-6 levels in serum and urine of children with primary nephrotic syndrome (PNS) before and after glucocorticoid treatment. METHODS: Thirty-eight children with PNS, including 30 cases with steroid-responsive and 8, steroid-resistant,and 19 age-matched healthy children were enrolled in this study. Serum and urinary IL-6 levels were examined by ELISA before and after prednisone treatment (2 mg/kg daily for 8 weeks). RESULTS: Before prednisone treatment, the serum levels of IL-6 in the steroid-responsive group (118.74±31.18 ng/L) and steroid-resistant group (129.62±28.14 ng/L) were significantly higher than those in the normal controls (35.13±16.21 ng/L)(P<0.05). The IL-6 levels in urine of the steroid-responsive and steroid-resistant groups (14.19±4.87 and 22.54±5.35 ng/L) were also significantly higher than those in the normal controls(3.62±1.87 ng/L) (P<0.05). The IL6 levels of urine were significantly different between the steroid-responsive and steroid-resistant groups.After the treatment with prednisone for 8 weeks, the levels of IL-6 in serum and urine in the steroid-responsive group were significantly reduced to 41.68±18.94 and 5.11±1.31 ng/L respectively, which were not different from those in the normal controls. But the IL-6 levels in serum and urine of the steroid-resistant group did not decrease significantly after prednisone treatment. CONCLUSIONS: The detection of IL-6 levels in serum and urine is useful for the identification of steroid-responsive PNS and for the estimation of the prognosis of PNS.
