Haemostatic Changes in Ulcerative Colitis and their Correlations with Disease Activity

Background: Hypercoagulability is supposed to be a feature of ulcerative colitis. Several mechanisms can be responsible for this, including abnormal coagulation activity, disturbances of fibrinolytic pathway and thrombocytosis.

The Aim was: 1) To study the changes in the natural anticoagulant   proteins (protein C, S and antithrombin III) and correlate them with disease activity.2) To study the changes in the fibrinolytic system (fibrinogen and D- dimer) and correlate them with disease activity. 3) To investigate whether the mean platelet volume would be a useful marker of ulcerative colitis activity.

Patients: A group of 18 patients diagnosed as ulcerative colitis by clinical, endoscopic and histological criteria were included in the study. Disease activity was assessed by a previously described simple colitis activity index.  A control group of 18 healthy subjects (sex and age matched). was also included.

Methods: For all cases and controls the following tests were done

• ESR, complete blood count and serum albumin
• Anticoagulant markers: protein C, S and antithrombin III
• Fibrinogen and D-dimer

Results: The studied patients were classified into mild to moderate (eight patients) and severe (ten patients) according to ulcerative colitis activity index. Platelet count was significantly increased in patients compared to healthy control (P < 0.0001) and in severe compared to mild to moderately active cases (P < 0.0001). Mean platelet volume was significantly reduced (P < 0.0001) in patients compared to healthy control and in severe compared to mild to moderate disease. No significant difference was noted between patients and controls regarding protein C and S.  Anti thrombin III was significantly reduced in patients compared to controls (P < 0.0001) and in severe compared to mild to moderate cases. Fibrinogen and D-dimer were significantly increased (P < 0.001 and 0.01 respectively) in patients compared to controls. Disease activity index (DAI) was positively correlated with mean platelet count, fibrinogen and D- dimer, but negatively correlated with mean platelet volume and antithrombin IIII. 

Conclusion: In this study coagulation was activated in ulcerative colitis patients indicated by thrombocytosis, increased fibrinogen and deficiency of antithrombin III. Fibrinolysis was also activated in UC patients indicated by elevated D-dimer. MPV is a useful, simple and uncosty parameter in evaluation of UC activity and it is negatively correlated with UC disease activity index.