A 22-year-old woman with lifelong mucocutaneous bleeding has a platelet count of 90,000 per microliter. Ristocetin-induced platelet aggregation is enhanced even at low ristocetin concentrations. Plasma vWF antigen is normal. Her father has identical findings. Which statement about management is correct?

• A Desmopressin is the treatment of choice for bleeding episodes
• B Desmopressin should be avoided because it can worsen thrombocytopenia ✓
• C Platelet transfusion is contraindicated in this condition
• D The defect lies in the platelet GPIb receptor

Explanation

Enhanced aggregation at low-dose ristocetin with thrombocytopenia defines type 2B von Willebrand disease, in which a gain-of-function vWF mutation increases binding to platelet GPIb, causing spontaneous binding and clearance of both vWF and platelets. Desmopressin releases abnormal vWF from stores and can precipitate marked worsening of thrombocytopenia, so it is avoided. Treatment is vWF-containing factor VIII concentrate. The defect is in the vWF gene, unlike platelet-type pseudo-vWD, which is a GPIb mutation with the same laboratory picture.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.