The team investigated the relationship between abnormal von Willebrand factor and bleeding gastrointestinal angiodysplasias, and reported their findings in this month's Gastroenterology.
27 patients with either non-bleeding (group A) or bleeding (group B) digestive angiodysplasias or telangiectasias, or diverticular hemorrhage (group C) were enrolled in the prospective study.
There were 9 patients in each group.
An analysis of von Willebrand factor, and a screening for the most common disorders associated with an acquired von Willebrand disease, were performed in the patients.
In all patients from groups A and C, von Willebrand factor was found to be normal, and no underlying disease could be detected.
|Number of patients with abnormal von Willebrand factor:|
Non-bleeding angiodysplasia/diverticular hemorrhage: None
Bleeding angiodysplasia : 8/9
In contrast, all but one patient from group B had a variable selective loss of the largest multimeric forms of von Willebrand factor, associated in 7 cases with a stenosis of the aortic valve.
Researcher Agnes Veyradier, of the Kremlin Bicêtre, Paris, France, concluded on behalf of the group, "This study indicates that most patients with bleeding angiodysplasia or telangiectasia have a deficiency of the largest multimers of von Willebrand factor induced by a latent acquired von Willebrand disease.
"Because these multimers are the most effective in promoting primary hemostasis at the very high shear conditions related to these vascular malformations, we suggest that their deficiency is likely to contribute to the bleeding diathesis."