Assessment of anti-prothrombin antibodies in thrombosis complicating inflammatory bowel diseases.

PURPOSE: In inflammatory bowel diseases (IBD), risk of thrombosis and production of antibodies are increased. In autoimmune and inflammatory disorders, a role of anti-prothrombin (aPT) antibodies in developing thrombosis has been hypothesised. The aim of the study is to evaluate the prevalence of aPT antibodies in IBD patients, with and without thrombosis.

METHODS: Thirty-three IBD patients with thrombosis, 33 IBD patients without thrombosis matched for sex, age, diagnosis and disease activity and 66 sex- and age-matched healthy controls were enrolled. Thrombosis was considered recent when blood sample was obtained within 3 months from the event.

RESULTS: Prevalence of aPT antibodies in thrombotic IBD patients (3/33, 9.1 %), non-thrombotic IBD patients (4/33, 12.1 %) and in healthy subjects (3/66, 4.5 %) did not result significantly different (p = 0.377). The prevalence of aPT antibodies was more frequent in ulcerative colitis (6/32, 18.7 %) than in Crohn's disease (1/34, 2.9 %) and healthy controls (p = 0.022). Among thrombotic IBD patients, the prevalence of aPT antibodies was higher in those with recent (2/9, 22.2 %) than in those with previous thrombosis (1/24, 4.2 %) (p = 0.103). All thrombotic IBD patients with aPT antibodies were affected by ulcerative colitis with previous history of deep venous thrombosis.

CONCLUSIONS: aPT antibodies do not appear to play a relevant role in thrombosis complicating IBD course. A possible association in ulcerative colitis patients with DVT could not be excluded.