Causes of Acquired von Willebrands Disease Type II in Pediatric Patients. Cases and literature review.

Objective Acquired bleeding disorders in childhood are rare. Acquired von Willebrands disease type two (avWDII) being one example that can cause significant bleeding complications. It may be caused by multiple underlying diseases. Usually patients are quite sick which complicates diagnosis significantly. Willebrand parameters are usually elevated to more than two times of the upper limit (especially after a bleeding episode) as an acute phase reaction. This may lead physicians to discard avWDII as a possible reason for bleeding. However several mechanisms can lead to loss of large and super-large Willebrand multimers causing a significant bleeding phenotype. The ratio of Willebrand factor quantity and activity may point towards avWDII but is not 100% reliable. The diagnosis can be made by Willebrand multimer analysis.

Aim: Raise disease awareness for von avWDII as a treatable cause of bleeding.

Material and Methods We report on patients with mostly severe clinical bleeding phenotypes that have been diagnosed with avWDII. Patients received comprehensive diagnostic coagulation work-up.

Results Patients were aged 4 – 14 years and suffered from complications after allogenic hematopoetic stem cell transplantation (n=4), thrombocytosis (n = 3), liver disease caused by biliary atresia, treated by portocaval shunt (n=1) and congenital heart defects (n=1).

Patients with thrombocytosis had mild bleeding complications that were treated with tranexamic acid. All other patients had prolonged hospital stays due to bleeding and 5/9 patients received multiple blood transfusions to substitute blood loss. In 5/9 patients bleeding was stopped or significantly reduced after iv substitution of Willebrand factor. In 3/9 patients avWDII was resolved after the underlying cause was cured.

Conclusion AvWDII may be a transient cause for bleeding in sick children. Bleeding symptoms can successfully be treated with iv substitution of Willebrand factor.

Publication History

Article published online:
18 June 2021