Publications by authors named "Johan Boender"
Article Synopsis
- Genotyping is generally not done when diagnosing von Willebrand disease (VWD), leaving a gap in understanding the genetic causes and how they affect different patient phenotypes, particularly in type 1 VWD.
- A study analyzed the gene in 390 VWD patients, revealing that genetic variants were present in a majority of cases (61.5% for type 1, 98.4% for type 2, and 100% for type 3), with many novel variants identified.
- The research highlighted distinct clinical features between type 1 VWD patients with and without gene variants, indicating that understanding these genetic factors could significantly improve patient management and treatment approaches.
Patients with type 1 and type 2 von Willebrand disease (VWD) can be treated with desmopressin. Although a previous study has shown that the location of the causative VWF gene variant is associated with desmopressin response in type 1 VWD, the association between variants in the VWF gene and desmopressin response is not yet fully understood. Our primary aim was to compare desmopressin response in type 1 VWD patients with and without a VWF gene variant.
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- This study focuses on validating VWF multimer densitometric analysis for classifying von Willebrand disease (VWD), aiming to improve upon the existing visual analysis methods that are time-consuming and less accurate.
- Researchers analyzed blood samples from 560 VWD patients using Western blotting and IMAGEJ for detailed measurements of VWF multimer patterns, achieving high accuracy rates in distinguishing various VWD types and multimer conditions.
- Findings revealed that the medium-large VWF multimer index was not only reliable for classification but also showed a correlation with bleeding severity in type 1 VWD patients, suggesting it could enhance understanding of the disease's clinical features.
Article Synopsis
- * Researchers measured ADAMTS-13 activity in 638 individuals with VWD and found it to be comparable to healthy controls, with higher activity in type 3 VWD patients compared to type 1 and type 2.
- * Despite these differences, ADAMTS-13 activity showed no significant association with the bleeding phenotype, as measured by the Tosetto bleeding score, indicating it does not influence bleeding severity in VWD patients.
Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is mainly caused by dominant-negative mutations in the multimeric protein von Willebrand factor (VWF). These mutations may either result in quantitative or qualitative defects in VWF. VWF is an endothelial protein that is secreted to the circulation upon endothelial activation.
View Article and Find Full Text PDFThe bleeding phenotype of patients with type 1 von Willebrand disease (VWD) is very heterogeneous. We hypothesized that this heterogeneity may partly be explained by variability in response of von Willebrand factor (VWF) and factor VIII (FVIII) levels to stress during hemostatic challenges. We therefore investigated whether VWF and FVIII levels after administration of desmopressin, which mimic in vivo hemostatic response during hemostatic challenges, explain the heterogeneity in bleeding phenotype of patients with type 1 VWD.
View Article and Find Full Text PDFLow ADAMTS13 activity is associated with an increased risk of cardiovascular disease, which is generally attributed to its proteolytic effects on Von Willebrand factor (VWF). Cardiovascular health is an important determinant of cognitive decline, but the association of either VWF or ADAMTS13 with risk of dementia is unknown. Between 1997-2002, we measured VWF antigen and ADAMTS13 activity in 6055 participants of the population-based Rotterdam Study (mean age 69.
View Article and Find Full Text PDFBackground: Altered levels of von Willebrand factor (vWF) and ADAMTS13 can promote thrombosis and disturb blood flow in kidney microcirculations. We investigated the association of serum vWF:ADAMTS13 ratio in relation to decline in kidney function.
Study Design: Prospective cohort study.
The bleeding phenotype of children with von Willebrand disease (VWD) needs to be characterized in detail to facilitate diagnosis during childhood and aid in the planning and assessment of treatment strategies. The objective was to evaluate the occurrence, type, and severity of bleeding in a large cohort of children with moderate and severe VWD. We included 113 children (aged 0-16 years) with Type 1 (n = 60), 2 (n = 44), and 3 (n = 9) VWD with von Willebrand factor (VWF) antigen and/or VWF ristocetin cofactor levels ≤ 30 U/dL from a nation-wide cross-sectional study ("Willebrand in the Netherlands" study).
View Article and Find Full Text PDFA disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13) cleaves von Willebrand factor, reducing its prothrombotic activity. The genetic determinants of ADAMTS13 activity remain unclear. We performed a genome-wide association study of ADAMTS13 activity in the Rotterdam Study, a population-based cohort study.
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