title: Platelet-type von Willebrand Disease: Diagnostic Challenges. Flaws and Pitfalls Experienced in the THROMKID Quality Project.
abstract: BACKGROUND
  Primary haemostasis defects comprise von Willebrand disease (VWD) and platelet disorders (PD). Although presenting with mild to moderate bleeding tendency in most cases, severe bleeding and blood loss may occur unexpectedly in trauma and surgery. Diagnosis of VWD and PD often remains difficult owing to the wide spectrum of clinical and laboratory manifestations. Platelet-type von Willebrand disease (PT-VWD) is frequently misdiagnosed as type 2B VWD. Discrimination between type 2B VWD and PT-VWD is crucial as treatment differs.
  
  
  RESULTS
  A literature review revealed difficulties in diagnostic work-up and choice of optimal treatment of PT-VWD. Guidelines favour the therapeutic use of platelet concentrates. A telephone survey of diagnostic practice with regard to type 2B VWD/PT-VWD was conducted. The prevalence and incidence of type 2B and PT-VWD remained unclear, but PT-VWD may be underestimated.
  
  
  CONCLUSIONS
  An international study estimated that PT-VWD constitutes up to 15% of the total number of patients diagnosed with type 2B VWD. Our survey confirmed difficulties with diagnosis and showed that some centres did not exclude PT-VWD in type 2B patients. Some authors emphasize that genetic testing is the gold standard for diagnosis, but functional testing allows immediate diagnosis. Due to the important therapeutic implications we suggest that type 2B VWD be confirmed by genetic testing and that in case of a negative result PT-VWD should be excluded.
  
  
  CONCLUSIONS
  PT-VWD should be excluded in all suspected cases of type 2B. PT-VWD should be treated with platelet concentrates.
authors.affiliation: Department of Paediatrics, Medical University of Innsbruck (MUI), Austria.
authors.forename: M
authors.initials: M
authors.lastname: Maurer
authors.affiliation: Department of Interal Medicine, Haematology/Oncology, University of Münster, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Mesters
authors.affiliation: Department of Paediatric Haematology and Oncology, University Medical Centre Hamburg-Eppendorf, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schneppenheim
authors.affiliation: Department of Pediatric Haemostaseology, Medical Faculty Carl Gustav Carus of Technical University Dresden, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Knoefler
authors.affiliation: Department of Paediatrics, Medical University of Innsbruck (MUI), Austria.
authors.forename: W
authors.initials: W
authors.lastname: Streif
mesh_terms: D002648:Child; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005820:Genetic Testing; D019983:Guideline Adherence; D006801:Humans; D017713:Platelet Transfusion; D058996:Quality Improvement; D014842:von Willebrand Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000628:therapy