FIBRINOLYTIC SPLIT PRODUCTS, FIBRINOLYSIS, AND FACTOR-XIII ACTIVITY IN INFLAMMATORY BOWEL-DISEASE

Background: Factor XIII (F XIII), the last coagulation factor in the c lotting cascade, plays a role in mucosal repair. Beneficial effects of F XIII supplementation in severe ulcerative colitis (UC) have been ob served. The aim of this study was to relate plasma F XIII activity to the severity of inflammatory bowel disease (IBD). Methods: A transvers ional and, in part, longitudinal study of F XIII activity and related clotting products was performed in 39 patients with UC, 31 patients wi th Crohn's disease (CD), and 20 controls. Disease activity was assesse d with a combined activity score in UC and with the Dutch Activity Ind ex in CD. Results: F XIII activity was decreased in active UC (p < 0.0 5) and active CD (p < 0.05) and was inversely correlated with severity in both UC (r = -0.30) and CD (r = -0.46). In six patients with UC (1 5%) and six patients with CD (19%) F XIII activity was below the lower range of normal. In these patients apparent rectal bleeding was only found in severe UC. Hyperfibrinolysis was indicated by elevated levels of D-dimer (p < 0.001) notwithstanding increased concentrations of al pha-2 antiplasmin (p < 0.05). Conclusions: In active IBD we found decr eased plasma F XIII activity and hyperfibrinolysis. Decreased F XIII a ctivity was not associated with apparent rectal bleeding in IBD.