Association between interleukin-4 and interleukin-10 single nucleotide polymorphisms and multiple sclerosis among Iraqi patients

Multiple sclerosis (MS) is a neurodegenerative autoimmune disease, in which cytokines play a prominent role. Among these cytokines are interleukin-4 (IL-4) and IL-10, which have been demonstrated to be involved in immunopathogenesis of the disease. The present case-control study inspected the association between seven single nucleotide polymorphisms (SNPs) of IL4 (IL4(-1098): rs2243248, IL4(-590): rs2243250, and IL4(-33): rs2070874), IL4RA (IL4RA(+1902): rs1801275), and IL10 (IL10(-1082): rs1800896, IL10(-819): rs1800871, and IL10(-592): rs1800872) genes and MS in Iraqi patients. Sixty-eight clinically definite relapsing-remitting MS Iraqi patients and 158 age- and gender-matched healthy control subjects were enrolled in the study. The SNPs were detected by the PCR-SSP (polymerase chain reaction-sequence specific primer) method. Results revealed that only IL4(-1098), IL4(-590), IL4(-33), and IL10(-592) SNP allele and/or genotype frequencies showed a significant variation between MS patients and control. At the haplotype level, the estimated frequency of TCC (IL4(-1098)-IL4(-590)-IL4(-33)) and GCC (IL10(-1082)IL10(-819)-IL10(-592)) haplotypes was significantly increased in patients compared to control (TCC: 63.2 vs. 48.0%; odds ratio= 2.81; 95% confidence interval = 1.86-4.25; pc = 5.0 x 10(-6); GCC 39.0 vs. 22.2%; odds ratio = 2.24; 95% confidence interval = 1.45-3.46; pc = 0.002). In conclusion, IL4 and IL10 genes harbor important SNPs that may conferMS susceptibility. In addition, their role in reducing the risk of disease is also suggested. However, the susceptibility of the investigated role can be better evaluated in terms of haplotype frequencies.