Evidence for activation of coagulation in Crohn's disease

Abstract

Haemostatic changes in 16 patients with Crohn's disease were studied from active disease into clinical remission and beyond. Elevated concentrations of fibrinopeptide A (FpA) and prothrombin fragments F1 + 2 (F1 + 2) were found at times of both active (FpA median 3.2, range [0.3–40] ng/ml and F1 + 2 median 2.3, range [0.3–18] nm/1) and inactive disease (FpA median 2, range [0.4–40] ng/ml and F1 + 2 median 1.3, range [0.2–20) nm/1]. We also measured the physiological inhibitors of coagulation and fibrinolysis; there was no significant difference in the levels of antithrombin III, protein C or the Exner ratio between active and inactive disease. Free protein S levels were significantly lower in active disease (median 34, range 9–54 U/dl) than in remission (median 40, range 12–65 U/dl). Plasminogen activator inhibitor type 1 (PAI-1) was significantly raised in remission (median 11, range 3–32 ng/ml) when compared to active disease (median 7, range 3–42 ng/ml). The D-dimer correlated significantly with fibrinopeptide A (P < 0.001), suggesting reactive fibrinolysis in some patients. Most (35/52, 67%) samples showed evidence of persistent haemostatic activation (elevated FpA and/or F1 + 2) during phases of apparent clinical remission in Crohn's disease, a factor that is not reflected by clinical activity scores. This study supports the hypothesis that coagulation is activated in the mesenteric vasculature of patients with Crohn's disease.