The association of -330 interleukin-2 gene polymorphism and HLA-DR15 allele in Iranian patients with multiple sclerosis.

Abstract

The purpose of this case-control study was to evaluate the frequencies and potential genetic susceptibility of the -330 IL2 T and G alleles and HLA-DRB1*1501 allele in Iranian patients with multiple sclerosis (MS) compared to healthy controls. Two hundred and sixty Iranian patients with MS from medical genetics department of Sarem Women hospital were selected. Besides, 450 ethnically age- and sex-matched healthy individuals without personal or family backgrounds of autoimmune disorders were enrolled as a control group. All polymorphisms were analysed using RFLP-PCR technique. HLA-DRB1 genotyping was carried out by HISTO TYPE SSP high-resolution Kits according to the manufacturer's suggestions. The frequency of the T allele at the -330 IL2 polymorphism was significantly higher in patients with MS than controls (OR: 2.45, 95 CI: 1.9-3, P = 4 × 10(-14) ). Moreover, the T/T genotype was more frequent in patients than in controls (51% vs. 30%). This study indicated that the -330 T IL2 allele and the T/T genotype were related to increased plasma concentration of IL2 and a higher risk of developing MS among Iranian patients. Carrying both the -330 T IL2 and the HLA, DRB1* 1501 alleles showed the most susceptibly effect to MS. Our data demonstrated -330 T IL2 allele provided major susceptibility to MS and HLA-DRB1* 1501 allele had an additive effect. In addition, it seems that studies with larger sample size are required to bring about more authentic results. Our findings suggest that IL2 gene polymorphisms influence the susceptibility to MS in Iranian patients.