Genetic variations in the KIR gene family may contribute to susceptibility to ankylosing spondylitis: a meta-analysis.

The present meta-analysis of relevant case-control studies was conducted to investigate the possible relationships between genetic variations in the killer cell immunoglobulin-like receptor (KIR) gene clusters of the human KIR gene family and susceptibility to ankylosing spondylitis (AS). The following electronic databases were searched for relevant articles without language restrictions: the Web of Science, the Cochrane Library Database, PubMed, EMBASE, CINAHL, the Chinese Biomedical Database (CBM) and Chinese National Knowledge Infrastructure (CNKI) databases, covering all papers published until 2013. STATA statistical software was adopted in this meta-analysis as well. We also calculated the crude odds ratios (OR) and its 95% confidence intervals (95 % CI). Seven case-control studies with 1,004 patients diagnosed with AS and 2,138 healthy cases were implicated in our meta-analysis, and 15 genes in the KIR gene family were also evaluated. The results of our meta-analysis show statistical significance between the genetic variations in the KIR2DL1, KIR2DS4, KIR2DS5 and KIR3DS1 genes and an increased susceptibility to AS (KIR2DL1: OR 7.82, 95% CI 3.87-15.81, P< 0.001; KIR2DS4: OR 1.91, 95% CI 1.16-3.13, P = 0.010; KIR2DS5: OR1.51, 95% CI 1.14-2.01, P = 0.004; KIR3DS1: OR 1.58, 95% CI 1.34-1.86, P< 0.001; respectively). However, we failed to found positive correlations between other genes and susceptibility to AS (all P >0.05). The current meta-analysis provides reliable evidence that genetic variations in the KIR gene family may contribute to susceptibility to AS, especially for the KIR2DL1, KIR2DS4, KIR2DS5 and KIR3DS1 genes.