Factor V Leiden and inflammatory bowel disease: a systematic review and meta-analysis

Recent studies proved that inflammatory bowel disease (IBD) patients had a higher risk of thromboembolism and a Factor V Leiden mutation that prevents the efficient inactivation of factor V, which leads to thromboembolism and thus contributes to a high potential risk of IBD. However, the relationship between Factor V Leiden mutation and IBD remains controversial.

We conducted a systematic review with meta-analysis of studies assessing the association of Factor V Leiden mutation with the risk of IBD in humans. We extracted the number of IBD and control subjects with or without Factor V Leiden mutation from each study and conducted this analysis using a fixed-effects model.

Nineteen studies met the inclusion criteria and were included in the meta-analysis. No significant heterogeneity was found in results across the 19 studies (I (2) = 18.8%, P = 0.23), which showed a slight but not significant increase in the risk of IBD with Factor V Leiden mutation in the general population (summary odds ratio [OR] 1.13, 95% confidence interval [CI] 0.87-1.46). Taking into account ethnic differences, further study exhibited a slight but not significant increase in risk of IBD with Factor V Leiden mutation in Europeans (summary OR 1.20, 95% CI 0.88-1.64). However, Factor V Leiden mutation was significantly associated with a higher risk of thromboembolism in IBD patients (summary OR 5.30, 95% CI 2.25-12.48). No publication bias was found in this study.

This meta-analysis indicated that although Factor V Leiden mutation was not significantly associated with the risk of IBD, it was significantly associated with a higher risk of thromboembolism in IBD patients.