An investigation of the association of the factor V Leiden mutation and inflammatory bowel disease

Background A thrombotic aetiology for inflammatory bowel disease (IBD) has been proposed as a result of its association with thrombo-embolic complicat ions, smoking, the oral contraceptive pill and the response of ulcerative c olitis (UC) patients to heparin. The factor V Leiden (FVL) mutation is the commonest inherited risk factor for thrombo-embolism. Aim The aim of the study was to investigate the hypothesis that the pro-thr ombotic state associated with the FVL mutation is involved in the aetiology of IBD. Patients and methods A prospective cohort study of patients attending the B ristol Royal Infirmary IBD outpatient clinic was performed, Fifty-four pati ents with IBD (30 with Crohn's disease (CD) and 24 with UC) and 55 historic al controls were screened for the presence of FVL using the activated prote in C (APC) ratio. Abnormal APC ratios were confirmed to be due to NL using a heteroduplex-based polymerase chain reaction (PCR) technique. Results Five patients had the FVL mutation, compared to two controls. One o f the patients was homozygous. Two of the patients had CD and three UC. The differences between controls and IBD patients was significant when the all elic frequency of the FVL mutation in patients with UC was compared with co ntrols, with a risk ratio of 2.27, but with limited data. Conclusion There appears to be a weak association between FVL and UC. This association is not strong enough to imply a causal relationship, but may be responsible for some of the thrombo-embolic complications. Eur J Gastroent erol Hepatol 11:1289-1291 (C) 1999 Lippincott Williams & Wilkins.