Internal Medicine

0521779407-22 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:23

1546 Von Willebrand Disease

VON WILLEBRAND DISEASE

MORTIMER PONCZ, MD and MICHELE LAMBERT, MD

history & physical

■Easy bruising

■Recurrent epistaxis or other mucosal bleeding

■Menorrhagia

■Hemorrhage after injury or surgery; especially tonsillectomy, ade-

noidectomy, dental extraction

■Hemarthrosis (only with certain subtypes)

■Associated with congenital hemorrhagic telangiectasia (Osler-

Weber-Rendu syndrome) and can see acquired vWD with Wilms

tumor

■Family history of excessive bleeding (particularly menometrorrha-

gia) or vWd (most common type [type 1] is autosomal dominant)

tests

■CBC, PT, PTT: PTT usually normal but can be prolonged; platelets

can be decreased in type 2B vWD

■Bleeding time: usually prolonged but can be normal (rarely done)*

■von Willebrand factor (vWf ) level: normal values depend on blood

type. Can be artificially increased by high-dose estrogens (OCP or

pregnancy) or high stress levels

■Factor VIII level: lower in type 2N vWd

■vWf activity (ristocetin cofactor): low in vWd – levels do not depend

on blood type; may also be elevated with high-dose estrogen;

ristocetin induces vWf binding to platelet GPIb; lower ratio of

ristocetin cofactor to vWf level with normal multimers in type

2M vWd

■Willebrand factor multimers: all multimers decreased in type 1 (most

common variant – 5% of the general population); all multimers

absent in type 3 (autosomal recessive or compound heterozygous

inheritance); high-molecular-weight multimers decreased in type

2B and platelet-type pseudo vWd, absent in type 2A vWd

■Low-dose ristocetin-induced platelet aggregation: increased in type

2B vWd. vWf and ristocetin cofactor can intermittently be normal:

if significant bleeding history, repeat labs at least 3 times over 3–6

months.