Trasi Sucheta, Shetty Shrimati, Ghosh Kanjaksha, Mohanty Dipika
Institute of Immunohaematology, Mumbai, India.
Indian J Med Res. 2005 May;121(5):653-8.
von Willebrand disease (VWD) is one of the most common inherited bleeding disorders in the west. Limited studies from India showed a prevalence of approximately 10 per cent of VWD among the cases with hereditary bleeding disorders. VWD remains an underdiagnosed entity in India. The prevalence of different subtypes of VWD is also not known which is essential for a proper management of these cases. The present study was thus undertaken to know the prevalence of VWD and its various subtypes in the western part of our country.
A total of 796 consecutive patients presented with various bleeding manifestations were analysed. The initial screening and confirmation tests for the diagnosis of VWD included bleeding time (BT), screening coagulation tests i.e., prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), factor VIII: C assay, ristocetin-induced platelet aggregation (RIPA) and VWF antigen (VWF:Ag) estimations. VWF multimer analysis, ristocetin cofactor activity (RCOF), VWF collagen binding assay (VWF: CBA), factor VIII : VWF binding assay were also done to classify and subtype these cases.
The patients were subtyped as per the International Society of Thrombosis and Haemostasis (ISTH) criteria. Of the 796 patients screened, 58 were diagnosed as VWD. Of the 15 families with a positive family history of bleeding, 26 additional cases were diagnosed as VWD. Majority of the patients were type 3 (59.5%) with severe clinical manifestations, about 18 per cent of type 1 VWD patients were detected in this group while the prevalence of the qualitative variants of VWD i.e., type 2 VWD was found to be 19 per cent and the prevalence of various subtypes were type 2A (9.52%), type 2B (4.76%), type 2M (1.2%), type 2N (3.6%).
The high prevalence of type 3 and a low prevalence of type 1 VWD which is in contrast to the western reports, suggests the low awareness of the disease as also the underdiagnosis of the mild cases in our country.
血管性血友病（VWD）是西方最常见的遗传性出血性疾病之一。印度的有限研究表明，在遗传性出血性疾病病例中，VWD的患病率约为10%。在印度，VWD仍然是一种诊断不足的疾病。VWD不同亚型的患病率也不清楚，而这对于妥善管理这些病例至关重要。因此，本研究旨在了解我国西部VWD及其各种亚型的患病率。
对796例连续出现各种出血表现的患者进行分析。VWD诊断的初始筛查和确认试验包括出血时间（BT）、筛查凝血试验，即凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、凝血酶时间（TT）、因子VIII：C测定、瑞斯托霉素诱导的血小板聚集（RIPA）和血管性血友病因子抗原（VWF：Ag）测定。还进行了VWF多聚体分析、瑞斯托霉素辅因子活性（RCOF）、VWF胶原结合试验（VWF：CBA）、因子VIII：VWF结合试验，以对这些病例进行分类和亚型划分。
根据国际血栓与止血学会（ISTH）标准对患者进行亚型划分。在796例筛查患者中，58例被诊断为VWD。在15个有出血家族史阳性的家庭中，另外26例被诊断为VWD。大多数患者为3型（59.5%），有严重临床表现，该组中约18%为1型VWD患者，而VWD的定性变异型即2型VWD的患病率为19%，各亚型的患病率分别为2A型（9.52%）、2B型（4.76%）、2M型（1.2%）、2N型（3.6%）。
3型患病率高而1型VWD患病率低，这与西方报告相反，表明我国对该疾病的认识不足，轻度病例诊断不足。
