Genetic association between TAP1 and TAP2 polymorphisms and ankylosing spondylitis: a systematic review and meta-analysis.

Abstract

Ankylosing spondylitis (AS) is a chronic inflammatory joint disease. The transporter associated with antigen processing (TAP) has been identified to play an important role in immune response as well as the HLA-associated diseases. The aim of our meta-analysis was to investigate the contribution of TAP (TAP1 and TAP2) polymorphisms to the risk of AS. Meta-analyses were performed between 2 polymorphisms in TAP1 (TAP1-333, -637) and 3 polymorphisms in TAP2 (TAP2-379, -565, and -665) and AS. The meta-analyses were involved with 6 studies with 415 cases and 659 controls. Significant association was found between TAP1-333Val, TAP1-637Gly, and TAP2-565Thr and AS compared with combined control group (TAP1-333Val: p=0.009, OR=1.40, 95% CI 1.09-1.80; TAP1-637Gly: p=0.002, OR=1.48, 95% CI 1.15-1.91; p=0.03, OR=1.38, 95% CI 1.04-1.84). Subgroup analysis shown that significant association was only found in AS when compared with HLA-B27-negative controls (TAP1-333Val: p=0.004, OR=1.53, 95% CI 1.14-2.06; TAP1-637Gly: p=0.004, OR=1.52, 95% CI 1.15-2.02; p=0.02, OR=1.56, 95% CI 1.09-2.24), but not in AS when compared with HLA-B27-positive controls (p>0.05). Moreover, no significant associations were found between haplotypes in TAP1 and TAP2 in both the combined and the subgroup analyses (p>0.05). TAP1-333Val, TAP1-637Gly, and TAP2-565Thr were likely to be associated with AS.