Laboratory aspects of von Willebrand disease : test repertoire and options for activity assays and genetic analysis
Author
Summary, in English
The deficiency or abnormal function of von Willebrand factor (VWF) causes von Willebrand disease (VWD), the most frequent inherited bleeding disorder. The laboratory diagnosis of VWD can be difficult as the disease is heterogeneous and an array of assays is required to describe the phenotype. Basic classification of quantitative (type 1 and 3) and qualitative (type 2) VWD variants requires determination of VWF antigenic (VWF:Ag) levels and assaying of VWF ristocetin cofactor (VWF:RCo) activity, determining the capacity of VWF to interact with the platelet GPIb-receptor. Knowing the VWF:RCo activity is essential for identifying, subtyping and monitoring VWD, but the assay is poorly standardized and many protocols do not fulfil the clinical need in all situations. This has led to the development of novel activity assays, independent of ristocetin, with enhanced assay characteristics. Results from the first independent clinical evaluations are promising, showing that they are reliable and suitable for VWD diagnosis. The qualitative type 2 VWF deficiency can be further divided into four different subtypes (A, B, M and N) using specific assays that explore other activities or the size distribution of VWF multimers. These methods are discussed herein. However, in a number of patients it may be difficult to correctly classify the VWD phenotype and genetic analysis may provide the best option to clarify the disorder, through mutation identification.
Publishing year
2014
Language
English
Pages
65-70
Publication/Series
Haemophilia
Volume
20
Document type
Journal article review
Publisher
Wiley-Blackwell
Topic
- Hematology
Keywords
- Blood Coagulation Tests/methods
- Genetic Testing
- Humans
- Ristocetin
- von Willebrand Diseases/blood
- von Willebrand Factor/chemistry
Status
Published
ISBN/ISSN/Other
- ISSN: 1351-8216