5 research outputs found
Clinical and laboratory variability in a cohort of patients diagnosed with type 1 VWD in the United States
Von Willebrand disease (VWD) is the most common inherited bleeding disorder, and type 1
VWD is the most common VWD variant. Despite its frequency, diagnosis of type 1 VWD
remains the subject of much debate. In order to study the spectrum of type 1 VWD in the United
States, the Zimmerman Program enrolled 482 subjects with a previous diagnosis of type 1 VWD
without stringent laboratory diagnostic criteria. VWF laboratory testing and full length VWF
gene sequencing were performed for all index cases and healthy control subjects in a central
laboratory. Bleeding phenotype was characterized using the ISTH Bleeding Assessment Tool.
At study entry, 64% of subjects had VWF:Ag or VWF:RCo below the lower limit of normal,
while 36% had normal VWF levels. VWF sequence variations were most frequent in subjects
with VWF:Ag < 30 IU/dL (82%) while subjects with type 1 VWD and VWF:Ag ≥ 30 IU/dL had
an intermediate frequency of variants (44%). Subjects whose VWF testing was normal at study
entry had a similar rate of sequence variations as the healthy controls at 14% of subjects. All
subjects with severe type 1 VWD and VWF:Ag ≤ 5 IU/dL had an abnormal bleeding score, but
otherwise bleeding score did not correlate with VWF:Ag level. Subjects with a historical
diagnosis of type 1 VWD had similar rates of abnormal bleeding scores compared to subjects
with low VWF levels at study entry. Type 1 VWD in the United States is highly variable, and
bleeding symptoms are frequent in this population
Examining international practices in the management of pregnant women with von Willebrand disease
Background
The management of pregnant women with von Willebrand disease (VWD) is complex as physiological pregnancy-induced increases in plasma von Willebrand factor (VWF) may be blunted or absent. Women with VWD experience a heightened risk of postpartum hemorrhage (PPH) and special consideration must be given regarding neuraxial anesthesia (NA) and the need for prophylaxis at time of delivery. These challenges are compounded by a lack of robust evidence to guide clinical decision-making.
Objectives and Methods
To determine the current international clinical practices in the management of pregnancy for women with VWD, the International Society on Thrombosis and Haemostasis (ISTH) conducted an international survey of health-care providers (HCP).
Results
One hundred thirty-two respondents from 39 countries were included in the final analysis. Variations in clinical practice were identified in antenatal (monitoring of plasma VWF and ferritin levels), peripartum (optimal plasma VWF target at delivery) and postpartum management (definitions used for PPH and postpartum monitoring). A key area of divergence was suitability for NA for women with type 2 and type 3 VWD, with many respondents advising against the use of NA even with VWF supplementation (29% type 2 VWD, 37% type 3 VWD) but others advising use once plasma VWF activity was >50 IU/dL (57% type 2 VWD; 50% type 3 VWD).
Conclusions
This survey highlighted areas of uncertainty surrounding common management issues for pregnant women with VWD. These data underscore the need for international collaborative research efforts focused on peripartum management to improve care for pregnant women with VWD