IL-33 polymorphism rs1929992 and its association with susceptibility to different pattern of multiple sclerosis

Background: Multiple sclerosis is the most common autoimmune demyelinating disease of the central nervous system (CNS). Interleukin-33 (IL-33) is a cytokine with both pro-inflammatory and anti-inflammatory activities that implicated in the pathogenesis of some autoimmune diseases. The aim of this study was to determine single nucleotide polymorphism (SNP) of IL-33, rs1929992, in patient’s gene with multiple sclerosis (MS) and investigation of this polymorphism with susceptibility to MS. Methods: In this case-control study, peripheral blood samples were collected from 140 MS patients (patients in the Afzalipur Hospital in Kerman) and blood sample of 140 healthy subjects (people referred to the Blood Transfusion Organization) as a control group from March 2016 to January 2018. SNP at rs1929992 was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: There was significant difference between healthy control group and patient with multiple sclerosis in the frequency of genotypes. The frequency of AA genotype at rs1929992 was significantly higher in the MS group in comparison with healthy control subjects (P= 0.0001), whereas frequency of AG genotype was significantly higher in the control group as compared with MS group (P= 0.02). There was no significant difference between the MS patients and healthy control group in GG genotype. Moreover, the frequencies of AA genotype at SNP rs1929992 were significantly higher in patients with secondary progressive MS (SP-MS) and primary progressive MS (PP-MS) as compared with control group (P= 0.03). However, the frequencies of AG genotype was significantly lower in patients with relapsing-remitting MS (RRMS) in comparison to the healthy group (P= 0.01). In patients with RR-MS, PP-MS and SP-MS patterns, the frequencies of A allele was significantly higher than that in control group (P= 0.03, P= 0.01, P= 0.001). In patients with RR-MS, PP-MS and SP-MS pattern, the frequency of G allele was significantly lower than control group (P= 0.03, P= 0.01, P= 0.001). Conclusion: The results of this study suggest that the SNP rs1929992 in IL-33 gene, may be associated with different pattern of MS susceptibility.