Association of KIR genotype with susceptibility to HLA-B27-positive ankylosing spondylitis.

OBJECTIVE Recent studies have explored the role of killer cell immunoglobulin-like receptors (KIRs) in chronic autoimmune diseases. The purpose of this study was to demonstrate whether KIR genes contribute to the pathogenesis of ankylosing spondylitis (AS) in Chinese populations. METHODS Sixteen KIR genes were genotyped from 60 unrelated patients with AS and 60 HLA-B27-positive matched healthy controls by PCR-SSP. The frequencies of the KIR alleles and genotypes in the AS and control groups were assessed by the χ(2) test. RESULTS Our results showed that the frequency of the activator receptor KIR3DS1 gene in the AS group was significantly increased compared to the controls (χ(2) = 5.263, P = 0.006, OR = 3.059, 95 % CI = 1.357-6.896). Moreover, the frequency of the KIR3DL1/3DS1 genotype was greater in the AS group than in the control group (P = 0.039, OR = 3.059, 95 % CI = 1.357-6.896). In contrast, the frequency of the no KIR3DL1/no 3DS1 genotype was lower in patients with AS compared with the controls (P = 0.032, OR = 0.110, 95 % CI = 0.013-0.911). CONCLUSION KIR3DS1, in addition to HLA-B27, may play an important independent role in the pathogenesis of AS in the Chinese population.