Venous Thromboembolism Among Patients With Inflammatory Bowel Diseases is Not Related to Increased Thrombophilia: A Case-Control Study

Abstract

Goal: The aim was to assess whether thrombophilia significantly contributes to the risk of venous thromboembolic events (VTEs) in patients with inflammatory bowel disease (IBD).

Background: Patients with IBD have a high risk of VTE. The underlying mechanism has been only partially defined.

Methods: A case-control study in adults with IBD and an episode of VTE (IBD-VTE) were matched and compared with non-IBD patients with a VTE (non-IBD-VTE). The study population was comprised of patients seen in 2 tertiary medical centers in Israel between 2000 and 2013. Characteristics of IBD and risk factors for VTE were retrieved from medical charts, and a comprehensive thrombophilia panel was completed in all patients.

Results: Forty-four IBD-VTE cases (27 Crohn's disease) were matched with 127 non-IBD-VTE controls. The majority of VTE had a clear etiology and were considered provoked events. Provoked and unprovoked VTE rates were not different between the 2 groups. Likewise, thrombophilia rates were similar among patients with IBD-VTE and controls (40.9% vs. 53.5%, respectively, P=0.14). However, among patients with unprovoked VTE, thrombophilia rates were significantly lower in the IBD-VTE group compared with controls (42.1% vs. 70.7%, respectively, P=0.03). Among patients with IBD-VTE, an unprovoked event, and negative thrombophilia, 77% had active inflammation at the time of VTE.

Conclusion: Thrombophilia rates are similar among patients with IBD-VTE and controls but are less common among patients with unprovoked IBD-VTE. This finding suggests that either inflammation or other novel pathways drive VTE in patients with IBD.