Vitamin D receptor gene polymorphism influences lipid profile in patients with juvenile idiopathic arthritis

Vitamin D receptor (VDR) gene FokI (rs2228570) polymorphism was postulated to influence outcome of several inflammatory diseases. The aim of this study was to evaluate the influence of rs2228570 polymorphism on lipid profile and on outcome in patients with juvenile idiopathic arthritis (JIA) treated with etanercept. A total of 153 subjects (62 JIA patients and 91 controls) were screened for the rs2228570 using the PCR-RFLP method. Lipid profile (cholesterol, triacylglycerol, HDL-C, and LDL-C) was determined using standard biochemical analysis in controls, while in JIA patients, it was determined prior to and 12 months after anti-TNF (etanercept) therapy. Clinical outcome was assessed using the JIA-American College of Rheumatology (ACR) response criteria. There were significant differences in the distribution of genotypes (p = 0.024) and alleles (p = 0.006; OR = 2.222, 95% CI 1.136-4.348) of the rs2228570 between patients and controls. Etanercept treatment significantly increased HDL-C levels (p = 0.006) in JIA patients with FF genotype in comparison to baseline values. No significant differences were seen in JIA-ACR 30/50/70 responses at month 12 between FF and Ff/ff genotype carriers. This is the first study to demonstrate the protective effect of the VDR FokI FF genotype on lipid profile in JIA patients treated with etanercept. However, this has to be confirmed in a larger cohort of patients.