n Medical Technology SA - The use of an algorithm for the laboratory diagnosis of von Willebrand disease
|Article Title||The use of an algorithm for the laboratory diagnosis of von Willebrand disease|
|© Publisher:||The Society of Medical Laboratory Technologists of South Africa (SMLTSA)|
|Journal||Medical Technology SA|
|Author||Muriel Meiring, Philip N. Badenhorst and Mareli Kelderman|
|Publication Date||Jun 2005|
|Pages||15 - 18|
Von Willebrand Disease (vWD) is a bleeding disorder caused by either quantitative (type 1 and 3) or qualitative (type 2) defects of von Willebrand factor (vWF). No single test is available that provides appropriate information about the various functions of vWF and the laboratory diagnosis of vWD is based on a panel of tests that includes the measurement of factor VIII coagulant activity (VIIIC), vWF antigen (vWF:Ag), vWF activity as measured by ristocetin cofactor activity (vWFR:Co), vWF multimer analysis, ristocetin induced platelet agglutination (RIPA), the factor VIII binding assay of plasma vWF and the bleeding time. Due to the heterogeneity of vWF defects and the variables that interfere with vWF levels, a correct diagnosis of types and subtypes may sometimes be difficult but is very important for therapy. Furthermore, the Ristocetin Cofactor test and the RIPA test are based on platelet agglutination in reaction with the non-physiological antibiotic, ristocetin. These tests also have low sensitivity and are difficult to standardise. Therefore, several analyses (tests) are required to diagnose vWD and it is important to take the pitfalls that these tests are subject to in consideration in the diagnosis of vWD. <br>In this article, the laboratory diagnosis of vWD is presented on patients with type 1, 2A, 2B and 2M vWD. The diagnosis is done by using an algorithm that is proposed by the guidelines for diagnosis and treatment of vWD in Italy. The pitfalls in this diagnosis of vWD are outlined by 4 other patients.
Article metrics loading...