title: Acquired von Willebrand Syndrome During the Course of Myelofibrosis: Analysis of 32 Cases.
abstract: BACKGROUND
  Identification of patients with myelofibrosis being at increased risk of acquired von Willebrand syndrome (avWS) would likely facilitate individualization of treatment and improve its outcomes.
  
  
  OBJECTIVE
  To determine the prevalence of avWS in patients with myelofibrosis, and to verify if individuals with and without this bleeding disorder differ in terms of their baseline clinical parameters.
  
  
  METHODS
  The study included 32 consecutive patients with myelofibrosis. avWS was diagnosed on the basis of abnormally low levels of von Willebrand factor and other routine tests. Patients with and without concomitant avWS were compared in terms of their demographic characteristics, present and past medical histories and laboratory parameters.
  
  
  RESULTS
  Concomitant avWS was found in 5 patients (15.6%). In 1/5 patients with avWS and in 8/27 persons without this bleeding disorder, myelofibrosis developed secondarily to polycythemia vera (n = 7) or essential thrombocytopenia (n = 2). As many as 4/5 individuals with avWS presented with clinical evidence of a bleeding disorder. The subjects with avWS differed from the remaining patients with myelofibrosis in terms of significantly lower activity of von Willebrand factor (vWF) and lower vWF to vWF antigen ratio.
  
  
  CONCLUSIONS
  All patients with myelofibrosis should be routinely evaluated for avWS with the panel of specific tests. Further, avWS should be the primary suspicion in each patient with myelofibrosis in whom clinical evidence of a bleeding disorder has emerged.
authors.affiliation: Department of Hematology and Transplantology, Medical University of Gdańsk, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Mital
authors.affiliation: Department of Hematology and Transplantology, Medical University of Gdańsk, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Prejzner
authors.affiliation: Department of Hematology and Transplantology, Medical University of Gdańsk, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Hellmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D055728:Primary Myelofibrosis / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014842:von Willebrand Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D015415:Biomarkers; D014841:von Willebrand Factor