PB0841 - Investigation of VWD in Women with Menorrhagia or Dysmenorrhea Associated with Bleeding

Background: Von Willebrand disease (VWD) is an inherited bleeding disorder characterized by quantitative/qualitative deficiencies of von Willebrand factor (VWF). VWD patients often experience mucocutaneous bleeding, and a systematic review using data mainly based on western countries reported approximately 13% of women with menorrhagia had VWD.

Aims: Thus, the prevalence of VWD in Japanese women with menorrhagia or dysmenorrhea was investigated in this study.

Methods: Japanese women aged 45 years or younger who visited gynecologists for treatment of menorrhagia or dysmenorrhea and agreed to participate in this study with written informed consent (IC) were registered. Data regarding blood type, family history, bleeding symptoms and their treatment, bleeding assessment by ISTH/SSC Bleeding Assessment Tool (BAT), and blood tests including VWF:RCo, VWF:Ag, and FVIII:C were collected. When VWD or other bleeding disorders was suspected in the first visit assessment, VWF multimer analysis was added in the second assessment, and a coagulation specialist independent of study sites adjudicated VWD and other bleeding disorders according to the JSTH (The Japanese Society on Thrombosis and Hemostasis) guidelines. This study was approved by the independent ethics committee (UMIN000046174) and sponsored and funded by Takeda Pharmaceutical Company Limited.

Results: IC was obtained from 156 patients at 12 study sites, and 154 eligible patients were registered. Seventy-two (72) patients were suspected of VWD after the first assessment, and 69 patients among them received the second one. Finally 13 (8.4%) of the 154 patients were adjudicated as VWD with VWF:RCo: 36.00±7.23% (20.0–45.0) and VWF:Ag: 48.80±6.05% (39.0–61.0), [Mean ± SD, (min–max)] in the second assessment (n=10). Besides, 24 (15.6%) patients were adjudicated as “other bleeding disorders” showing decreased FVIII:C without abnormality in VWF tests.

Conclusion(s): This is the first evidence to indicate that VWD in Japanese women with menorrhagia or dysmenorrhea is underrecognized due to misdiagnosis or delay in diagnosis.