Division of Internal and Cardiovascular Medicine, Department of Internal Medicine, University of Perugia, Via E dal Pozzo, 06126 Perugia, Italy.
Haematologica. 2010 Jun;95(6):1021-4. doi: 10.3324/haematol.2009.015990. Epub 2009 Nov 30.
Platelet-type von Willebrand disease (PT-VWD) is a rare autosomal dominant bleeding disorder which is due to a mutation in the gene encoding for platelet glycoprotein Ibalpha (GPIbalpha) resulting in enhanced affinity for von Willebrand factor (VWF). PT-VWD is often mistakenly diagnosed as type 2B VWD for the similarities between these two conditions. We characterized a new case of PT-VWD and evaluated the usefulness of a flow cytometric assay in the differential diagnosis between PT-VWD (n=1) and type 2B VWD (n=4). The flow cytometric assay was able to highlight the increased affinity of VWF for GPIbalpha as much as did RIPA and to differentiate the two diseases through mixing tests. Genetic analysis revealed a heterozygous point mutation in codon 239 of the GPIbalpha gene leading to a methionine to valine substitution (M239V). Flow cytometry represents a useful tool for the diagnosis of PT-VWD.
血小板型血管性血友病（PT-VWD）是一种罕见的常染色体显性遗传性出血性疾病，其病因是编码血小板糖蛋白 Ibα（GPIbalpha）的基因突变，导致其与血管性血友病因子（VWF）的亲和力增强。PT-VWD 常因与这两种疾病的相似之处而被误诊为 2B 型 VWD。我们对一例新的 PT-VWD 病例进行了特征描述，并评估了流式细胞术在 PT-VWD（n=1）和 2B 型 VWD（n=4）之间的鉴别诊断中的应用。流式细胞术能够像 RIPA 一样突出 VWF 与 GPIbalpha 的亲和力增加，并通过混合试验来区分这两种疾病。基因分析显示 GPIbalpha 基因密码子 239 处存在杂合点突变，导致蛋氨酸被缬氨酸取代（M239V）。流式细胞术是诊断 PT-VWD 的有用工具。
