Hemostasis disturbances in patients with ulcerative colitis (uc) can result from quantity and quality changes in blood coagulation factors synthesis (acute phase reaction) as well as their consumption in inflammatory processes affecting in large bowel. The aim of this study was to estimate a coagulation system activation in patients with uc.

Methods: 42 patients with uc, 21 in active and 21 in inactive disease phase as well as 26 healthy persons were studied. In all concentration of thrombin-antithrombin III complexes (TAT), antithrombin III and prekallikrein activities, von Willebrand factor (vWf) and fibrinogen concentrations, kaolin-kephalin time (aPTT), prothrombin level and platelets count were determined.

Results: In patients with uc higher level of TAT, fibrinogen and platelets count, lower level of prekallikrein activity and shorter aPTT were found than in control group. No significant differences in obtained results of hemostatic parameters between patients with active and inactive uc were found. Whereas, it was disclosed lower platelets count and fibrinogen concentration in cases with inflammatory process only to rectum limited in comparison with more extended inflammatory changes. Using multiple regression method it was found that in studied group the TAT concentration, marker of thrombin in vivo generation, was determined by: aPTT, fibrinogen level, disease severity, inflammatory process extension in large bowel, systemic acute phase reaction.

Conclusions: 1) In patients with uc independently of activity and extension of inflammatory process, the increase of in vivo throminogenesis expressed by higher TAT level was found. 2) Observed coagulation system disturbances may exert an influence on inflammatory process affecting large bowel and increase the risk of thrombotic complications in the course of uc.