von Willebrand's disease characterized by increased ristocetin sensitivity
and the presence of all von Willebrand factor multimers in plasma
L Holmberg, E Berntorp, M Donner and IM Nilsson
In eight members of one family, platelets in platelet-rich plasma
aggregated at much lower ristocetin concentrations than normal. Ivy
bleeding time was variously prolonged, and von Willebrand factor antigen
(vWF:Ag), ristocetin cofactor activity, and factor VIII coagulant activity
were decreased. Most of the affected members had had slight to rather
severe bleeding symptoms. Platelet-type von Willebrand's disease (vWD)
could be ruled out. All multimers of vWF:Ag were found in plasma as well as
platelets. Administration of 1-desamino- 8-D-arginine vasopressin (DDAVP)
to the propositus did not cause thrombocytopenia, and platelet-poor plasma
obtained immediately after did not aggregate normal platelets. The
molecular defect in this family, inherited as an autosomal dominant,
resembles the one in type IIB because of the response to ristocetin but
differs from IIB because all vWF:Ag multimers are present in plasma and the
response to DDAVP is atypical. We conclude that this family has a new
subtype of vWD and propose that structural as well as functional criteria
should be used for a proper classification of vWD.
Volume 68,
Issue 3,
pp. 668-672,
09/01/1986
Copyright © 1986 by The American Society of Hematology
