von Willebrand factor alloantibodies in type 3 von Willebrand disease

The development of neutralizing antibodies is a rare complication of von Willebrand disease treatment. In major surgical procedures for severe forms of the disease, the recognition of ineffective therapy and alternative treatment protocols are lifesaving. We report the case of a 6-year-old girl with type 3 von Willebrand disease in whom inhibitors were sought due to ineffective haemostasis together with lower than expected von Willebrand factor (VWF) recoveries after a surgical procedure. Replacement therapy first with recombinant factor VIIa and then with high doses of recombinant factor VIII in continuous infusion successfully stopped the bleeding. A high level of anti-VWF antibodies was determined by the immunological method. A frameshift mutation associated with premature termination codon (c.2435delC, p.Pro812ArgfsTer31) was determined in our patient. Although the reports on association of this mutation with inhibitor risk are inconsistent, it represents an evidence-based diagnostic and management practice in recognition of high-risk VWF genotype.