Intracellular Adhesion Molecule-1 K469E Gene Polymorphism and the Risk of Inflammatory Bowel Disease: A Meta-Analysis

Abstract

Background and objective: Several studies have evaluated the association of the K469E (rs5498, A/G) gene polymorphism in Intracellular Adhesion Molecule-1 (ICAM-1) with Inflammatory Bowel Disease (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC), in different populations. However, the results of these individual studies have been inconsistent. Therefore, a meta-analysis was performed. Methods:The current meta-analysis, which involved 3260 subjects from nine separate studies, was conducted to explore the relationship between the ICAM-1 K469E gene polymorphism and IBD. The pooled odds ratios (OR) and 95% Confidence Intervals (CI) were assessed using the random effect model. Data were analyzed using STATA software.Results: Overall, we observed no significant association between the ICAM-1 K469E gene polymorphism and IBD, CD, or UC. Stratification of cases by ethnicity revealed that the ICAM-1 K469E gene polymorphism was significantly associated with IBD only in the East Asian population (KK+KE vs. EE: OR=2.586, 95% CI=1.411-4.742; KK vs. KE+EE: OR=1.828, 95% CI=1.081-3.092; K vs. E: OR=1.739, 95% CI=1.240-2.439; EE vs. KK: OR=0.305, 95% CI=0.151-0.615). Conclusions:This meta-analysis suggested that the K469E polymorphism in ICAM-1 likely does not represent a major factor affecting susceptibility to IBD. However, additional large case-control studies should be performed to clarify the possible role of ICAM-1 in IBD, especially studies examining potential ethnic differences and/or genotypephenotype interactions.