Interleukin-6 Receptor Polymorphisms Contribute to the Neurological Status of Korean Patients with Ischemic Stroke

To investigate the contribution of the interleukin-6 receptor (IL-6R) gene single nucleotide polymorphisms (SNPs) to the neurological status of Korean patients with ischemic stroke (IS), two SNPs of the IL-6R gene (rs4845617, 5 UTR; rs2228144, Ala31Ala) were selected. IS patients were classified into clinical phenotypes according to two well-defined scores: the National Institutes of Health Stroke Survey (NIHSS) and the Modified Barthel Index scores. There were 121 IS patients and 291 control subjects. The SNP rs4845617 significantly contributed to the neurological status of patients with IS (P = 0.011 in codominant model 2, P = 0.006 in recessive model, and P = 0.008 in log-additive model). Allele frequencies of rs4845617 and rs2228144 demonstrated no significant difference in IS patients and controls. The AG and GG haplotypes differed between the NIHSS 1 (NIHSS scores < 6) group and the NIHSS 2 (NIHSS scores ≥ 6) group in patients with IS (P = 0.014, P = 0.0024). These results suggest that rs4845617 of the IL-6R gene is associated with the neurologic status of Korean patients with IS.