Bleeding Time in Treated Patients With Severe Von Willebrand Disease Is Not Corrected Only by Giving Normal Multimeric Plasma Von Willebrand Factor

Abstract

Even though it is generally held that cryoprecipitate (cryo) and fraction I-0 correct the prolonged bleeding time (BT) in patients with von Willebrand disease (VWD), perusal of reported data indicates that the correction is usually short lasting and often partial. We decided to do a controlled study of the relationship between the multimeric structure of von Willebrand factor (VWF) in 5 patients with severe VWD after infusion of three plasma concentrates : "wet" cryo, lyophilized (lyo) cryo, and fraction 1-0 given in random order. The dosage of concentrates was tailored to achieve post infusion levels of RiCof above the lower normal limit (50 U/dL) for at least 3 hours. The post-infusion BT values are shown in the table.These findings indicate that the attainment of a normal BT is the exception rather than the rule after infusion of three plasma fractions used for treatment of severe VWD. In all the concentrates the proportions of large VWF multimers, calculated by scanning the electrophoretic gels, were the same as in normal standard plasmas. An intact multimeric structure was recovered in post-infusion plasma of patients treated with wet cryo, whereas there was post infusion loss of large multimers after lyo and fraction I-O. In conclusion, an intact multimeric structure in post infusion plasmas is necessary but not sufficient to sustain a normal BT in VWD patients.