title: Acquired von Willebrand disease in Wilms' tumor patients.
abstract: OBJECTIVE
  A prospective study was performed to determine the incidence of acquired von Willebrand disease (vWD) in children with newly diagnosed Wilms' tumor.
  
  
  METHODS
  Fifty consecutive children with newly diagnosed Wilms' tumor were evaluated. Detailed family and bleeding histories were obtained in all cases. Laboratory evaluation included measurement of the circulating platelet count, bleeding time (BT), factor VIII (FVIII) and von Willebrand factor (vWF) levels, and ristocetin cofactor (RCoF) activity. A vWF multimer analysis was obtained in all cases in which vWD was suspected.
  
  
  RESULTS
  Four of 50 (8%) consecutive children with a diagnosis of Wilms' tumor were found to have acquired vWD. Laboratory findings indicated type III vWD in two patients and type I vWD in the other two.
  
  
  CONCLUSIONS
  The incidence of acquired vWD in association with Wilms' tumor merits further study through a large prospective trial. Such a trial should include careful family and clinical bleeding histories plus measurement of a platelet count, BT, coagulant FVIII and vWF levels, RCoF activity, and vWF multimer analysis. The response to 1-desamino-8-D-arginine vasopressin (DDAVP) should be tested in all patients with Wilms' tumor and acquired vWD, including patients with a type III profile, before an invasive procedure is performed. Successful use of DDAVP may avoid exposure of affected patients to blood products.
authors.affiliation: Department of Paediatrics, Hospital for Sick Children, Toronto, Canada.
authors.forename: M J
authors.initials: MJ
authors.lastname: Coppes
authors.forename: S W
authors.initials: SW
authors.lastname: Zandvoort
authors.forename: C R
authors.initials: CR
authors.lastname: Sparling
authors.forename: A O
authors.initials: AO
authors.lastname: Poon
authors.forename: S
authors.initials: S
authors.lastname: Weitzman
authors.forename: V S
authors.initials: VS
authors.lastname: Blanchette
mesh_terms: D001777:Blood Coagulation; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007680:Kidney Neoplasms / Q000097:blood / Q000150:complications*; D008297:Male; D011446:Prospective Studies; D009396:Wilms Tumor / Q000097:blood / Q000150:complications*; D014842:von Willebrand Diseases / Q000097:blood / Q000150:complications*