Differential behavior of coagulation factor XIII in patients with inflammatory bowel disease and in patients with giant cell arteritis.

The aim of this prospective study was to examine the role of coagulation factor XIII (FXIII) in relation to disease activity in inflammatory bowel disease (IBD) and in giant cell arteritis. Plasma FXIII activity was studied during active and inactive disease in newly diagnosed patients with Crohn's disease (CD; n = 20), ulcerative colitis (UC; n = 18) and giant cell arteritis (GCA; n = 19), in 3-month intervals (median follow-up 12 months). FXIII was also measured in two noninflammatory control groups, age and sex matched for IBD (n = 25) and GCA (n = 26). FXIII activity was significantly lower in active CD or UC than in active GCA or the noninflammatory controls. Both in CD and UC, FXIII activity correlated inversely with indices of clinical disease activity, the erythrocyte sedimentation rate, fibrinogen and C-reactive protein levels. Low FXIII activity is a characteristic feature of active IBD, and serial measurements may be useful to assess IBD activity.