von Willebrand Disease
The most common inherited bleeding disorder, caused by deficiency or dysfunction of von Willebrand factor (a protein essential for platelet adhesion). Desmopressin is a first-line treatment for mild forms — it stimulates release of stored von Willebrand factor and factor VIII from endothelial cells.
Technical Context
VWD is the most common inherited bleeding disorder (prevalence approximately 1% of the population, clinically significant in approximately 0.01%). Von Willebrand factor (VWF) is a large multimeric glycoprotein that mediates platelet adhesion to damaged endothelium and carries coagulation factor VIII. VWD types: Type 1 (partial quantitative deficiency, ~70-80% of cases — mild bleeding), Type 2 (qualitative defects — subtypes 2A, 2B, 2M, 2N with different functional abnormalities), Type 3 (virtually complete VWF absence — severe bleeding, rare). Desmopressin relevance: DDAVP stimulates release of stored VWF from endothelial Weibel-Palade bodies via V2 receptor activation → transient increase in plasma VWF and FVIII levels (2-5× baseline within 30-60 minutes). Desmopressin is effective for Type 1 and some Type 2 VWD, making it first-line treatment for mild-moderate bleeding episodes and surgical prophylaxis in responsive patients. A test dose with VWF/FVIII measurement confirms responsiveness before clinical use.