The association of genetic polymorphisms in interleukin-1 receptors type 1 and type 2 with sudden sensorineural hearing loss in a Taiwanese population: a case control study.

BACKGROUND: Sudden sensorineural hearing loss (SSNHL) is a disease with an unknown etiology; damage to the auditory nerve from inflammation due to viral infection or vascular incidents has been implicated. According to several studies, cytokines, including interleukins, are associated with SSNHL in terms of serum expression and genetic polymorphisms. Interleukin-1 (IL-1) plays a key role in inflammation and may be associated with SSNHL. This study analyzed the association of single nucleotide polymorphisms (SNPs) of IL-1 receptor (IL-1R) genes with SSNHL in Taiwan. METHODS: We conducted a case-control study involving 401 patients with SSNHL and 730 healthy controls. Four SNPs (IL-1R type 1 gene [IL1R1] [rs3917225 and rs2234650] and IL-1R type 2 gene [IL1R2] [rs4141134 and rs2071008]) were selected. The genotypes were determined using the TaqMan assay. The Hardy-Weinberg equilibrium (HWE) was tested for each SNP, and genetic effects were evaluated. RESULTS: The TT genotype of rs2234650 had an adjusted odds ratio (OR) of 2.988 (95% confidence interval [95% CI] 1.27-6.82) (P = 0.012) compared with the CC genotype in patients with SSNHL. The SNP rs2234650 was associated with SSNHL in the recessive model (TT vs. CC + CT, P = 0.0206, OR = 2.681). The CT genotype of rs4141134 had an adjusted OR of 3.860 (95% CI 2.01-7.44; P < 0.0001) compared with the TT genotype, in patients with SSNHL. The SNP rs4141134 was associated with SSNHL under the dominant model (CC + CT vs. TT, P < 0.0001, OR = 4.087). CONCLUSION: These findings suggest that IL1R1 and IL1R2 gene polymorphisms may contribute to an increased risk of SSNHL in Taiwan.