Difference of Vitamin D and Interleukin-6 Levels in Children with Steroid- Resistant, Steroid-Sensitive and Idiopathic Nephrotic Syndrome

Idiopathic nephrotic syndrome (INS) is the most prevalent autoimmune glomerular disease in children and its pathogenesis is correlated with high level of interleukin 6 (IL-6) and low level of vitamin D. This study was aimed to investigate the difference of vitamin D and IL-6 level in steroid resistant nephrotic syndrome (SRNS), steroid sensitive (SSNS), and idiopathic nephrotic syndrome (INS). This research was designed as cross sectional involving 45 subjects which then divided into 3 groups as follows: SRNS, SSNS, and INS. A level of serum 25 (OH)D was measured by Enzyme-linked Immuno Assay Method then categorized as sufficiency, insufficiency, and deficiency. Level of IL-6 serum was measured by ELISA method. Results showed that IL-6 level was significantly different among three groups, in which SRNS had the highest value (ANOVA, p < 0.05). Further analysis demonstrated that IL-6 level correlated with steroid resistance (Spearman correlation test, p = 0.000, r = 0.692). Vitamin D status was significantly different among three groups (Chi square, p = 0.03) and associated with steroid resistance (Spearman correlation test, p = 0.000, r = 0.568). Moreover, IL-6 level associated with 25 (OH) D level in SRNS group (Pearson correlation test, p = 0.020, r = 0.591) but not in the SSNS and INS group. We conclude that IL-6 levels were significantly higher in SRNS group as compared to other groups. Otherwise, vitamin D status were significantly lower in SRNS compared with other groups. An IL-6 level was negatively correlated with vitamin D status in patients with NS, specifically in SRNS group.