VPB0724 - Online survey of Chinese patients with von Willebrand disease and the impact of COVID-19

Background: As of November 12, 2021, the China Hemophilia Information Registry has recorded 39,030 cases of hemophilia, of which only 482 cases of Von Willebrand disease(VWD). Obviously, this data is far from reaching the true number of VWDs in China. Therefore, the analysis of clinical characteristics of Chinese VWD patients needs to be resolved urgently.

Aims: This study described the clinical features, diagnosis and treatment plan of 96 Chinese patients with VWD in detail, and also analyzed the von Willebrand factor (VWF) gene mutation in some patients. In addition, the impact on patients with VWD during COVID-19 was collected.

Methods: The study conducted an online questionnaire survey of patients in a VWD communication group, and the data were analyzed in SPSS version 25.0.

Results: The results showed that 80% of patients had their first bleeding before the age of 5 years. 58% of the first bleeding site was epistaxis. 46% were misdiagnosed on first visit, such as Hemophilia, Epistaxis, Pseudohemophilia, Thrombocytopenia, Platelet weakness, Functional uterine bleeding, Coagulation dysfunction. There were differences between age at diagnosis and sex (P=.014) and VWD classification (P=.034). Cryoprecipitation (38%) is currently the most commonly used treatment for von Willebrand disease in China. Only 19% of patients were using prophylaxis. Drug shortages (68%) were the biggest problem patients faced during the pandemic. At present, the biggest appeal of VWD patients (64%) is to hope that the country can independently develop or allow the import of foreign recombinant VWF drugs. We found 21 VWF gene mutation sites in 14 patients, of which 18 were reported for the first time in the world. (p.H1536N, p.R507G, p.C2389R, p.Q393X, p.W2444X, p.W974X, p.E1015X, c.4413delC /4414delG,c.6085-6091delGTCTCTG, c.6496-6497insTCCT, c.2501-2502insA, c.6949dupG, c.2186+1G>A, c.5842+5G>A, c.2684A>G, Exon17del, Exon4-Exon52 del,Exon11-Exon43del).

Conclusion(s): Our findings give Chinese clinicians provides guidance on early identification of abnormal bleeding in VWD，and expands the international VWF gene database.