Is the CARD8 rs2043211 polymorphism associated with susceptibility to Crohn's disease? A meta-analysis

Many studies have reported the association between the CARD8 gene polymorphism rs2043211 and the susceptibility to Crohn's disease (CD), but the results have remained quite contradictory. Therefore, the aim of the meta-analysis was to explore whether the CARD8 rs2043211 polymorphism has an effect on CD risk. We performed a systematic literature search for related articles published up to July 2014 in multiple databases. Six eligible articles containing eight studies were selected. Odds ratios (ORs) as well as their corresponding 95% confidence intervals (CIs) were used to estimate the association between the CARD8 polymorphism and CD risk in different genotypic models. Heterogeneity analysis was also performed and publication bias was taken into account. Subgroup analyses were conducted according to different ethnicities, as well as different types of CD. In the pooled analyses, no statistical significant association was found between the CARD8 polymorphism and CD risk in the overall population or Caucasian subgroup in the additive model (overall population: OR=0.93, 95% CI=0.87-1.01; Caucasian: OR=0.93, 95% CI=0.83-1.05). However, subgroup analysis based on different CD types showed a significant association between the CARD8 polymorphism and CD risk in the additive model (ileal CD: OR=0.83, 95% CI=0.70-0.98; stenotic or fistulizing CD: OR=0.81, 95% CI=0.72-0.92). Our results indicated that CD may involve different types of pathogenesis and have variable clinical manifestations. In patients with ileal, stenotic or fistulizing CD, the mutant-type rs2043211 polymorphism may generate a potentially protective effect.