Association of interleukin-1 family gene polymorphisms with juvenile idiopathic arthritis in Iranian population

Background Cytokines, including interleukin-1 (IL-1), seem to contribute towards the pathogenesis of juvenile idiopathic arthritis (JIA), so this study was designed to evaluate the associations of IL-1 gene cluster and IL-1 receptor (IL-1R) gene single nucleotide polymorphisms (SNPs) with JIA proneness in Iranian population. Materials and methods Genomic DNA of 55 Iranian patients with JIA and 140 controls were extracted and typed for IL-1α gene at position −889, IL-1β gene at positions −511 and +3962, IL-1R gene at position Pst-I 1970, and interleikin-1 receptor antagonist (IL-1Ra) gene at position Mspa-I 11100, using polymerase chain reaction with sequence-specific primers method, and compared between patients and controls. Results The CC genotype of IL-1Ra at Mspa-I 11100 position was found to be more frequent in patients with JIA compared to healthy individuals (P = 0.03), although the CT genotype at the same position was significantly higher in the control group in comparison with patients with JIA (P = 0.02). No significant differences were observed between the two groups of case and control for IL-1α (−889 C/T), IL-1β (−511 C/T and +3962 C/T) and IL-1R (Pst-1 1970 C/T). Conclusion The results of the present investigation suggest that certain IL-1Ra gene variants are associated with individuals’ susceptibility to JIA. Nevertheless, further studies are required to establish the results of the current study.