How I treat type 2B von Willebrand disease.

Type 2B von Willebrand disease (VWD) is an inherited bleeding disorder caused by changes in von Willebrand factor (VWF) that enhance binding of VWF to GPIb on platelets. Although this disorder is seemingly well defined because of this single molecular defect, in reality type 2B VWD is a clinically heterogeneous disorder that can be difficult to identify and manage. Diagnostic criteria include a history of mucocutaneous bleeding, laboratory studies showing enhanced VWF binding of platelets and/or a 2B VWD genetic variant, and a family history consistent with autosomal dominant inheritance. Thrombocytopenia, although not always present, is common and can be exacerbated by physiologic stressors such as pregnancy. The mainstay of therapy for type 2B VWD is VWF replacement therapy. Adjunct therapies useful in other types of VWD, such as antifibrinolytics, are also used in type 2B VWD. 1-Desamino-8-d-arginine vasopressin (DDAVP) is controversial because of exacerbation of thrombocytopenia, but is, in practice, sometimes used for minor bleeding. Here we review the available evidence and provide 3 clinical cases to illustrate the intricacies of diagnosing type 2B VWD to describe the response to DDAVP and to review complexities and management during pregnancy.