Association between interleukin-8 gene -251 T/A polymorphism and the risk of peptic ulcer disease: a meta-analysis.

It remains controversial regarding the association between interleukin-8 (IL-8) gene -251 T/A polymorphism and peptic ulcer disease (PUD) risk. Thus, a large-scale meta-analysis evaluating the precise association between this gene variant and PUD risk is required. We searched the PubMed, Embase, Web of Science, and Google Scholar until April 25, 2012. Additionally, hand searching of the references of identified articles were performed. All the statistical tests were performed using Stata 11.0. A total of eight studies (3105 subjects) were included in this meta-analysis. Overall, no significant association was found between IL-8 gene -251 T/A polymorphism and PUD risk (for A allele vs. T allele: OR = 1.17, 95% CI = 0.97-1.41, p = 0.094; for A/A vs. T/T: OR = 1.33, 95% CI = 0.94-1.90, p = 0.108; for A/A vs. A/T+T/T: OR = 1.22, 95% CI =0.97-1.52, p = 0.083; for A/A+A/T vs. T/T: OR = 1.26, 95% CI = 0.95-1.67, p = 0.113). However, in the subgroup analyses by ethnicity, H. pylori infection and the subtype of PUD, significant associations were found between IL-8 gene -251 T/A polymorphism and PUD risk in Asians, H. pylori+, duodenal ulcer disease (DUD) and gastric ulcer disease (GUD), respectively. In summary, the present meta-analysis suggests that IL-8 gene -251 T/A polymorphism is associated with increased PUD risk among Asians, and especially for the subgroups of H. pylori+, DUD and GUD.