Guidance on the diagnosis and management of platelet-type von Willebrand disease: A communication from the Platelet Physiology Subcommittee of the ISTH.

Platelet-type von Willebrand disease (PT-VWD) is a rare autosomal dominant platelet bleeding disorder, with 55 patients reported worldwide so far, probably frequently misdiagnosed. Currently, there are no clear guidelines for the diagnosis and management of PT-VWD and this may contribute to misdiagnosis and thus to inappropriate treatment of these patients. This report provides expert opinion-based consensus recommendations for the standardized diagnostic and management approach to PT-VWD. Tests essential in the diagnostic workup are platelet count and size, ristocetin-induced platelet agglutination with mixing studies, and sequencing of platelet GP1BA gene. Platelet transfusions and von Willebrand factor-rich concentrates (if VWF is low) are the most effective treatments. This consensus may help to avoid misdiagnosis and guide appropriate management of patients with this disease.