Levels and activities of von Willebrand factor and metalloproteinase with thrombospondin type-1 motif,number 13 in inflammatory bowel diseases

AIM To evaluate the levels of von Willebrand factor(VWF) and metalloproteinase with thrombospondin type-1 motif, number 13(ADAMTS13) in inflammatory bowel disease(IBD) and correlate them with the disease activity.METHODS Consecutive patients with IBD aged 18 years or older were enrolled in the study. Forty-seven patients with ulcerative colitis(UC), 38 with Crohn's disease(CD), and 50 healthy controls were included. The white blood cell count, haematocrit, platelet count, fibrinogen, partial activated thromboplastin time, C-reactive protein, albumin, VWF antigen level(VWF:Ag), VWF ristocetin cofactor activity(VWF:RCo), VWF collagen-binding activity(VWF:CB), and ADAMTS13 antigen level(ADAMTS13:Ag) and activity(ADAMTS13act) were measured. The following ratios were assessed: V W F : R C o/V W F : A g, V W F : C B/V W F : A g, V W F : A g/ADAMTS13 act, and ADAMTS13act/ADAMTS13:Ag. RESULTS Compared to controls, the odds ratio(OR) of an elevated VWF: Ag 150% was 8.7(95%CI: 2.7-28.1) in the UC group and 16.2(95%CI: 4.8-54.0) in the CD group. VWF:CB was lower in UC patients, and active CD was associated with a higher VWF: RCo(+38%). The ORs of VWF:CB/VWF:Ag 0.7(a marker of acquired von Willebrand syndrome) in the UC and CD groups were 11.9(95%CI: 4.4-32.4) and 13.3(95%CI: 4.6-38.1), respectively. Active UC was associated with lower ADAMTS13:Ag(-23%) and ADAMTS13act(-20%) compared to UC in remission. Patients with active CD had a 15% lower ADAMTS13 act than controls. The activity of UC, but not that of CD, was inversely correlated with ADAMTS13:Ag(r =-0.76) and ADAMTS13act(r =-0.81). CONCLUSION Complex VWF-ADAMTS13-mediated mechanisms disturb haemostasis in IBD. A reduced WVF:CB is a risk factor for bleeding, while a lower ADAMTS13 level combined with an elevated VWF:Ag could predispose one to thrombosis.