The Occurrence of Thrombosis in Inflammatory Bowel Disease Is Reflected in the Clot Lysis Profile

BACKGROUND The occurrence of thromboembolic events (TE) is an important extraintestinal manifestation in patients with inflammatory bowel disease (IBD). The aim of this study was to compare fibrinolysis and clot lysis parameters between (1) patients with IBD and healthy controls and (2) patients with IBD with TE (IBD + TE) and without TE (IBD - TE). METHODS One hundred thirteen healthy controls and 202 patients with IBD, of which 84 patients with IBD + TE and 118 patients with IBD - TE, were included in this case-control study. Three clot lysis parameters (area under the curve, 50% clot lysis time, and amplitude) were determined using a clot lysis assay. Plasminogen activator inhibitor 1 (PAI-1) and thrombin activatable fibrinolysis inhibitor concentrations were determined by enzyme-linked immunosorbent assay. RESULTS PAI-1 antigen, active PAI-1, and intact thrombin activatable fibrinolysis inhibitor concentrations, as well as 50% clot lysis time and area under the curve, were significantly associated with the presence of IBD (all P < 0.05). The median time between TE and plasma collection was 5.0 (1.8-11.0) years. Comparing IBD + TE versus IBD - TE, active to total PAI-1 ratio (0.36 [0.24-0.61] versus 0.24 [0.13-0.40]), area under the curve (31 [24-49] versus 22 [13-31]), 50% clot lysis time (110 [64-132] versus 95 [70-126] minutes), and amplitude (0.295 [0.222-0.436] versus 0.241 [0.168-0.308]) were significantly higher in IBD + TE (all P <0.05) and remained higher after adjustment for age, gender, C-reactive protein, type of disease, presence of comorbidities, and disease activity. CONCLUSIONS Patients with IBD have an altered clot lysis profile compared with healthy controls. Clot lysis parameters differ significantly between patients with IBD with and without a history of TE and should be included in the risk assessment.