Clinical and laboratory variability in a cohort of patients diagnosed with type 1 VWD in the United States.
Blood
; 127(20): 2481-8, 2016 05 19.
Article
em En
| MEDLINE
| ID: mdl-26862110
ABSTRACT
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 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. von Willebrand factor (VWF) laboratory testing and full-length VWF gene sequencing was performed for all index cases and healthy control subjects in a central laboratory. Bleeding phenotype was characterized using the International Society on Thrombosis and Haemostasis bleeding assessment tool. At study entry, 64% of subjects had VWF antigen (VWFAg) or VWF ristocetin cofactor activity below the lower limit of normal, whereas 36% had normal VWF levels. VWF sequence variations were most frequent in subjects with VWFAg <30 IU/dL (82%), whereas subjects with type 1 VWD and VWFAg ≥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 (14%). All subjects with severe type 1 VWD and VWFAg ≤5 IU/dL had an abnormal bleeding score (BS), but otherwise BS did not correlate with VWFAg. Subjects with a historical diagnosis of type 1 VWD had similar rates of abnormal BS compared with 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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Doença de von Willebrand Tipo 1
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article