title: Different bleeding risk in type 2A and 2M von Willebrand disease: a 2-year prospective study in 107 patients.
abstract: BACKGROUND
  Type 2A and 2M von Willebrand disease (VWD2A and VWD2M) are characterized by the presence of a dysfunctional von Willebrand factor (VWF) and a variable bleeding tendency. So far, a head-to-head comparison of the clinical history and bleeding risk between VWD2A and VWD2M has never been provided in a prospective manner.
  
  
  OBJECTIVE
  We assessed the bleeding incidence rate and clinical characteristics in two cohorts of 17 families (46 patients) with VWD2A and 15 families (61 patients) with VWD2M prospectively followed-up for 24 months. VWF gene mutations were characterized in all of them.
  
  
  RESULTS
  Mean bleeding score (BS) and VWF antigen at enrollment were significantly higher in VWD2A patients (P = 0.007). No correlation between VWF activity or factor VIII levels and the severity of BS was observed. The incidence rate of spontaneous bleeding requiring treatment was 107/100 patient-years (95% CI, 88.3-131) in VWD2A compared with 40/100 patient-years (95% CI, 30-53) in VWD2M (P < 0.001). The risk of bleeding was significantly higher in patients with BS ≥ 10 at enrollment compared with those with BS 0-2. Furthermore, 54 episodes of gastrointestinal bleeding occurred in 17/46 (36.9%) VWD2A patients and seven in 2/61 (3.3%) VWD2M patients (P < 0.0001).
  
  
  CONCLUSIONS
  Bleeding tendency in VWD2A is greater than that of VWD2M, is not explained by factor VIII or VWF levels and is mainly due to an increased incidence of gastrointestinal bleeding.
authors.affiliation: Department of Hematology and Hemophilia and Thrombosis Center, San Bortolo Hospital, Vicenza, Italy. castaman@hemato.ven.it
authors.forename: G
authors.initials: G
authors.lastname: Castaman
authors.forename: A B
authors.initials: AB
authors.lastname: Federici
authors.forename: A
authors.initials: A
authors.lastname: Tosetto
authors.forename: S
authors.initials: S
authors.lastname: La Marca
authors.forename: F
authors.initials: F
authors.lastname: Stufano
authors.forename: P M
authors.initials: PM
authors.lastname: Mannucci
authors.forename: F
authors.initials: F
authors.lastname: Rodeghiero
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005169:Factor VIII / Q000032:analysis; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D020022:Genetic Predisposition to Disease; D006470:Hemorrhage / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics / Q000628:therapy; D006489:Hemostatic Techniques; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation; D010641:Phenotype; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult; D056728:von Willebrand Disease, Type 2 / Q000150:complications* / Q000453:epidemiology / Q000235:genetics; D014841:von Willebrand Factor / Q000032:analysis / Q000235:genetics
chemical_list: D014841:von Willebrand Factor; D005169:Factor VIII