[Diagnosis of von Willebrand's disease subtypes by the analysis of multimeric composition of plasma von Willebrand factor].

: The accurate diagnosis of the type of von Willebrand's disease (vWD) is important for a better understanding of its pathogenesis and for adequate treatment decision. We assessed the usefulness of the analysis of the multimeric composition of von Willebrand factor (vWF) in the diagnosis of vWD variants. vWF is purified by gel filtration and polyclonal, heterologous antibodies are raised in rabbits, which are immunopurified and radioiodinated. These are used to reveal, by autoradiography, the bands of vWF of various molecular weights separated by electrophoresis in agarose gels. This procedure reveals that 74 (80%) out of 92 patients with vWD suffer the classic type (I) of the disease, 6 (6.5%) type as IIA, 6 (6.5%) as IIB and 6 (6.5%) as III. The test is necessary for the correct classification of the patients, but is complex, laborious and expensive; it should be performed in patients with high probability of vWD or after the generic diagnosis of vWD has been made.