The aim of this study was to determine whether polymorphisms of interleukin-1 (IL-1) confer susceptibility to ankylosing spondylitis (AS).

The authors conducted meta-analyses on associations between IL-1 polymorphisms and AS susceptibility, using fixed or random effects models. In order to avoid duplications and data previously subjected to meta-analysis, we performed meta-analysis on studies if new data on IL-1 polymorphisms in AS were reported.

A total of nine studies consisting of 20 separate comparisons of association between IL-1 polymorphisms and AS susceptibility were included in this meta-analysis. These were performed on European, Asian, and Latin American population samples. Meta-analysis revealed a significant association between the 2 allele of the IL-1F10.3 polymorphism (rs3811581) and the risk of developing AS in Europeans (OR=0.775, 95% CI=0.605–0.992, P=0.043). Furthermore, the OR of the 2 allele of IL-1A+889 (rs1800587) was found to be significantly increased in Europeans with AS (OR=1.357, 95% CI=1.085–1.697, P=0.007). However, meta-analyses of the IL-1B-511, IL-1B+3953, and ILF7.1 polymorphisms and of the variable numbers of tandem repeats of the IL-1 receptor antagonist gene (IL-1RN VNTR) revealed no association between AS and these polymorphisms.

In addition to the three known IL-1 polymorphisms, rs2856836, rs17561, and rs1894399, found in previous meta-analysis, this meta-analysis shows that the IL-1F10.3 and IL-1A+889 polymorphisms are associated with the development of AS in Europeans but not in Asians.