Assessment of Von Willebrand factor antigen and activity levels in inflammatory bowel diseases

Abstract

Background There is a close interaction between inflammation and coagulation. Hemostatic abnormalities are common in inflammatory bowel disease (IBD) with higher risk for a hypercoagulable state and prothrombotic conditions. In addition, a few cases of acquired coagulopathy with higher risk of bleeding have been reported. The involved pathophysiologic mechanisms are complex and incompletely understood. Objective This is a case–control study that aimed to assess the levels of Von Willebrand factor (VWF) in IBD as a marker of disease activity and its relation to higher risk of bleeding or thrombotic events. Patients and methods A total of 46 patients with IBD aged 18 years or older were enrolled in the study. After consenting, patients were divided into two groups: one group included 23 patients with active IBD and the other group included 23 patients with inactive IBD. Activity of Crohn's disease was assessed through the Harvey-Bradshaw index and activity in patients with ulcerative colitis was evaluated with the simple clinical colitis activity index. The white blood cell count, hemoglobin level, platelet count, activated partial thromboplastin time, C-reactive protein, erythrocyte sedimentation rate, albumin, fecal calprotectin, VWF antigen level (VWF:Ag), and VWF ristocetin cofactor activity (VWF:RCo) were measured. The VWF:RCo/VWF:Ag ratio was calculated. Results There were significant differences in the mean±SD of vWF antigen and vWF:RCo levels between active IBD group (189.30±62.83 and 101.73±23.42, respectively, P=0.001) and inactive IBD group 177.30±64.90 and 97.08±24.21, respectively, P=0.001). The IBD activity index was correlated with VWF antigen (r=0.78 P=0.001) and VWF:RCo levels (r=0.74 P=0.001). VWF antigen and VWF:RCo were correlated with fecal calprotectin (r=0.65, P=0.001, and r=0.67, P=0.001, respectively). The odds ratio of an elevated vWF antigen greater than 150% was 24 (95% confidence interval: 4.38–131.47) in the group with active IBD compared with the inactive IBD group. The VWF:RCo/VWF:Ag ratio of less than 0.7 which reflects the possibility of acquired Von Willebrand syndrome was detected in five patients (21.7%) with active IBD in comparison with only one patient (4.3%) in the inactive IBD group, with odds ratio of 6.1 (95% confidence interval: 0.65–57.1). Conclusion VWF antigen and activity levels can be used as markers for evaluation of IBD activity. Assessment of VWF in IBD could be significant for better hemostatic control of such patients. Activated coagulation system in IBD is well known; however, precautions for coexisting acquired functional coagulopathy should be considered.