Bleeding symptoms in patients diagnosed as type 3 von willebrand disease: results from 3WINTERS‐IPS, an international and collaborative cross‐sectional study

Background Type 3 von Willebrand’s disease (VWD) patients present markedly reduced levels of von Willebrand factor and factor VIII. Because of its rarity, the bleeding phenotype of type 3 VWD is poorly described, as compared to type 1 VWD. Aims To evaluate the frequency and the severity of bleeding symptoms across age and sex groups in type 3 patients and to compare these with those observed in type 1 VWD patients; to investigate any possible clustering of bleeding symptoms within type 3 patients. Methods We compared the bleeding phenotype and computed the bleeding score (BS) using the MCMDM‐1VWD bleeding questionnaire in patients enrolled in the 3WINTERS‐IPS and MCMDM‐1VWD studies. Results In 223 unrelated type 3 VWD patients, both the BS and the number of clinically relevant bleeding symptoms were increased in type 3 as compared to type 1 VWD patients (15. vs. 6.0 and 5 vs. 3). Intracranial bleeding, oral cavity, hemarthroses, and deep hematomas were at least five‐fold over‐represented in type 3 VWD. A more severe bleeding phenotype was evident in patients having VWF:Ag levels