Antiphospholipid antibodies in patients with inflammatory bowel disease

Antiphospholipid antibodies (e.g. anticardiolipin antibodies; aCL) are frequently associated with thrombotic events. In view of the evidence that thrombotic phenomena may complicate inflammatory bowel disease (IBD), we have measured aCL in patients affected by ulcerative colitis (UC) (n = 30) and Crohn's disease (CD) (n = 22). We demonstrated that 6/30 (20%) of UC and 8/22 (36%) of CD patients showed increased levels of aCL (p <0.004 and p <0.0001, respectively, compared with healthy controls). aCL from IBD patients bound the corresponding antigen more efficiently in the presence of bovine serum which contained β2-glycoprotein I, a lipid-binding inhibitor of coagulation. aCL did not correlate either with disease activity or extent. No patient had clinical manifestations and/or a history of thromboembolism, which can perhaps occur without overt clinical signs. aCL could be a risk factor for intestinal thrombotic phenomena.