Association study of functional −183G/A and 48892A/C polymorphisms of interleukin-6 receptor () gene in Japanese patients with migraine

Aim Although migraine has been associated with inflammation and vascular reactivity, its pathophysiology has remained unclear. The pro-inflammatory cytokine interleukin-6 (IL-6) has been implicated in pain modulation, immune regulation and vascular functions. In this study, we aimed to investigate the association between migraine and two single-nucleotide polymorphisms (SNPs) of interleukin-6 receptor ( IL-6R ). Methods In this case-control genetic association study, we analysed 63 patients with migraine with aura (MA), 113 patients with migraine without aura (MO), 35 patients with tension-type headache (TTH) and 62 healthy controls (CTL). All participants were unrelated Japanese individuals residing in the Sanin area of western Japan. A polymerase chain reaction-based restriction fragment length polymorphism assay was performed to detect the presence of two SNPs: −183G/A (rs4845617) in the promoter region and 48892A/C (rs8192284) in exon 9. Logistic regression analyses adjusted for age and sex were performed. Results The IL-6R 48892A/C C-allele was more prevalent in the MA group than in the CTL group (61.7% vs. 48.3%), with the homozygous 48892C/C genotype particularly enriched in the MA group (adjusted odds ratio 3.51, 95% CI 1.10–11.26, P = 0.034). No significant association was observed for the −183G/A polymorphism. Conclusions Our findings suggest that IL-6R 48892A/C (rs8192284) polymorphisms may be associated with susceptibility to migraine in the Sanin region of western Japan, with distinct associations observed for MA. These findings support the potential role of IL-6R–related inflammatory signalling in the pathophysiology of migraine. Trial registration Not applicable