Type 1/Type 2 Cytokine Serum Levels and Role of Interleukin-18 in Children with Steroid-Sensitive Nephrotic Syndrome

Abstract

Introduction: In view of the conflicting evidence of helper T cell type 1 (Th1) or type 2 (Th2) pattern of cytokine synthesis in steroid sensitive nephrotic syndrome (SSNS), this study aimed to assess type-1/type-2 cytokines level in different stages of SSNS and to evaluate the role of IL-18.
Methods: We prospectively studied thirty children with SSNS, aged 2–12 years. The children were evaluated in the active stage before treatment initiation and re-evaluated again during remission while still on steroid treatment. A subgroup of children (21/30) was also evaluated during remission after steroid withdrawal. The control group included 30 healthy age- and sex-matched controls. Serum levels of IL-2, IFN-ã, ÉL-4, IL-13 and IL-18 were measured by ELISA.
Results: IL-2 levels were not significantly different between children in different stages of SSNS and controls (p > 0.05). Levels of IL-4, IL-13 and IL-18 were significantly higher during the active stage of SSNS compared to remission and controls (p<0.05). Serum IFN-ã was significantly lower in children with active disease compared to remission stages and controls (p<0.05). In children with SSNS, serum levels of IL-18 correlated significantly with both IL-4 and IL-13 during all stages (r = 0.72 and p<0.0001, r = 0.82 and p<0.0001, respectively).
Conclusion: Children with active SSNS seem to have a shift to type-2 cytokine production, and IL-18 expression is significantly correlated with this type-2 immune response.

Keywords: Nephrotic Syndrome; Type 1 cytokines; Type 2 cytokines