Purpose: The interleukin-23 receptor (IL-23R) has been shown to be associated with ankylosing spondylitis (AS) in many different populations. This study examined whether IL-23R polymorphisms were associated with susceptibility to this disease in a Chinese Han population.
Methods: Three single-nucleotide polymorphisms (SNP), rs7517847, rs11209032, and rs17375018, were genotyped in 291 AS patients and 312 age-, sex-, and ethnically matched healthy controls using a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) assay.
Results: The genotype and allele frequencies of rs17375018, rs7517847, and rs11209032 were not different between the patients with AS and the healthy controls. On the one hand, stratification analysis indicated that the rs17375018 GG genotype and the G allele were increased in AS patients who were HLA-B27 positive (corrected p = 0.024, odds ratio [OR] 2.35, 95% CI 1.30-4.24; p c = 0.006, OR 1.98, 95% CI 1.28-3.07, respectively). On the other hand, the analysis according to clinical characteristics showed a significantly increased prevalence of the homozygous rs17375018 GG genotype and the G allele in patients with AS and uveitis compared with the controls (p c = 0.024 and p c = 0.024, respectively). In addition, haplotype analysis performed with the SHEsis platform revealed no significant difference concerning the haplotypes between AS patients and healthy controls.
Conclusions: In this study, the results suggested that the rs17375018 of IL23R was positively associated with HLA-B27-positive AS and that the rs17375018 GG of IL-23R was associated with AS concomitant with uveitis. We found no evidence for an association between the other two SNPs of IL-23R and AS.