title: Acquired von Willebrand syndrome in a 10-year-old girl with acute lymphoblastic leukaemia.
abstract: Following diagnosis of acute lymphoblastic leukaemia (ALL) in a 10-year-old girl, routine coagulation screening including von Willebrand factor antigen (VWF:Ag), ristocetin cofactor activity (VWF:RCo) and factor VIIIC (FVIII:C) detected no pathological findings. After the first HR2' element of the high-risk group of the ALL-BFM 2000 protocol, the patient demonstrated extensive bleeding symptoms and acquired von Willebrand syndrome was diagnosed. VWF:Ag (13%), VWF:RCo (13%) and FVIII:C (27%) were decreased. Multimer analysis showed a loss of large multimers and a loss in triplet structures. The observed pattern was thought to be typical for monoclonal IgG gammopathy; however, in this case, unexpectedly, biclonal IgM gammopathy (κ and λ) was detected. After treatment with intravenous immunoglobulin over 5 days, coagulation factors increased to normal levels. Although this effect was assumed to be at best only temporary, especially in a case of IgM gammopathy, no further bleeding symptoms have been observed.
  
  
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authors.affiliation: University Childrens's Hospital Münster, General Pediatrics, Albert-Schweitzer-Strasse 33, Muenster, 48149, Germany.
authors.forename: Isabel
authors.initials: I
authors.lastname: Dorn
authors.forename: Ulrich
authors.initials: U
authors.lastname: Budde
authors.forename: Michael C
authors.initials: MC
authors.lastname: Frühwald
authors.forename: Monika
authors.initials: M
authors.lastname: Pöppelmann
authors.forename: Ulrike
authors.initials: U
authors.lastname: Nowak-Göttl