Background: Patients with Crohn's disease (CD) are at increased risk for thromboembolism, and multifocal microvascular infarction has even been suggested as a pathogenetic mechanism in CD. Abnormalities in blood rheology may contribute to the thromboembolism.
Objectives: To assess blood rheology in CD patients.
Design: Prospective evaluation of rheological parameters.
Setting: Out-patients at the gastroenterological department of a university hospital.
Patients: Thirty-seven patients with inactive CD (Crohn's disease activity index (CDAI) < 150), 31 patients with active CD (CDAI > 150), and 39 control subjects with no CD were included in the study.
Methods: C-reactive protein and orosomucoid were used as serum inflammatory parameters. Fibrinogen, red cell aggregation (low shear, 3/s) and plasma viscosity were used as rheological parameters.
Results: Fibrinogen (active CD: median 530 mg/dl (interquartile range 410-630); inactive CD: 377 (316-499); and controls: 246 (220-280)), red cell aggregation (active CD: 9.97 arb. units (8.58-11.77); inactive CD: 9.03 (7.25-10.37); controls: 7.58 (7-8.52)); and plasma viscosity (active CD: 1.82 mPa.s (1.68-1.95); inactive CD: 1.72 (1.65-1.82), controls: 1.61 (1.58-1.64)) were all significantly higher in patients with active and inactive CD than they were in controls. Additionally, fibrinogen was significantly higher in patients with active CD than it was in patients with inactive CD. The rheological parameters correlated with serum inflammatory parameters.
Conclusion: Changes in blood rheology seem to be associated with inflammatory activity in patients with CD. These changes may be involved in the development of thromboembolism and the pathogenesis of mucosal inflammation, especially in patients with high inflammatory activity.