title: Factor V Leiden and thrombosis in patients with inflammatory bowel disease (IBD): a meta-analysis.
abstract: BACKGROUND
  Testing for genetic risks of Factor V Leiden ( FVL ) in inflammatory bowel disease (IBD) patients with thromboembolism (TE) is common, but the safety and utility of such testing need review.
  
  
  OBJECTIVE
  The aim of the present study was to investigate whether the FVL polymorphisms would be one inherited prothrombotic risk factor that could significantly increase the risk of thrombosis in patients with IBD.
  
  
  METHODS
  We performed an electronic databases search to identify published studies correlating the FVL mutations with four populations including one IBD group with TE complications, one control IBD group without TE complications, one control non-IBD group with TE complications and another healthy control (HC) group. Statistical analysis was performed with Review Manager (RevMan) 5.0. Sub-analysis/sensitivity analysis was also performed.
  
  
  RESULTS
  We identified 112 titles and included 22 studies in this meta-analysis. The odds ratio (OR) of TE in IBD patients with FVL was higher as compared with IBD patients (OR: 4.00; 95%CI: 2.04, 7.87) and HC (OR: 3.19; 95%CI: 1.38, 7.36). There was a 1.25-fold (95%CI: 0.90-1.74) increase in incidence of FVL gene mutation in IBD patients compared with HC. The FVL mutations were not significantly different between IBD patients with thrombosis and non-IBD patients with thrombosis (OR: 0.79; 95%CI: 0.43, 1.47).
  
  
  CONCLUSIONS
  FVL plays a role in IBD-TE, but to no greater extent than it does in the general population with TE.
authors.affiliation: Department of General Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
authors.forename: Xian Wen
authors.initials: XW
authors.lastname: Dong
authors.forename: Qing
authors.initials: Q
authors.lastname: Zheng
authors.forename: Jin Lu
authors.initials: JL
authors.lastname: Tong
authors.forename: Zhi Hua
authors.initials: ZH
authors.lastname: Ran
mesh_terms: D005165:Factor V / Q000235:genetics*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications*; D011110:Polymorphism, Genetic; D013923:Thromboembolism / Q000209:etiology / Q000235:genetics; D013927:Thrombosis / Q000209:etiology / Q000235:genetics*
chemical_list: C095381:factor V Leiden; D005165:Factor V