RESUMO
Background: Migraine is a chronic neurological disease characterized by recurrent moderate to severe headaches commonly in association with neuro-inflammation. Interleukin-4 [IL-4], an anti-inflammatory cytokine, plays an important role in modulating pain threshold and has an essential role in stimulation of pain receptors in the trigeminal nerve fibers
Aim of the study: The current study aimed to investigate the possible associations between IL-4 single nucleotide polymorphisms [SNPs] and susceptibility to migraine in Iranian patients
Patients and methods: In a prospective case-control study, we studied blood samples of 190 patients with migraine [migraineurs] and 200 healthy controls [HCs] for analysis of gene variants. Genotyping for the IL-4 SNPs: C-589T [rs2243250], T+2979G [rs2227284], and C-33T [rs2070874] were performed using PCR-RFLP. Statistical analysis was performed using the SPSS version 21.0 [SPSS, Chicago] and SNPStats version 1.14.0
Results and Conclusion: Among IL-4 SNPs, rs2243250 [TC genotype, OR= 0.25, 95% CI= 0.13-0.50, P = 0.001] and rs2227284 [TG and TT genotypes, OR= 0.44, 95% CI= 0.23-0.92, P = 0.029 and OR = 0.38, 95% CI= 0.18-0.79, P = 0.009 respectively] were significantly associated with migraine. No significant associations between IL-4 SNP rs2070874 [TC, TT and CC genotypes] and migraine were found. The most frequent genotypes in the migraineurs were CC in both SNPs rs2243250 [79%], and rs2070874 [71.5%], as well as GG for SNP rs2227284 [64%]. There was no statistically significant relationship between these SNPs and different subclasses [common, classic and complicated] of migraine. Our findings revealed that in IL-4 rs2243250 and rs2227284 genotypes and allele frequencies have a role in susceptibility to migraine in our population. Therefore, it is suggested that in addition to other factors, IL-4 genetic variations also play a pivotal role in the progress of migraine