title: Evaluation of three APTT reagents in a routine laboratory: toward a compromise.
abstract: BACKGROUND
  Our current activated partial thromboplastin time (APTT) reagent (PTT-A) is often prolonged for unexplained reasons.
  
  
  METHODS
  We decided to compare this reagent with an alternative reagent (Cephascreen) and with our second line APTT (Actin FS) in terms of cut-off values, sensitivity to in-vitro coagulation factor deficiencies, sensitivity to lupus anticoagulant (LA), and in vivo sensitivity to unfractionated heparin (UFH).
  
  
  RESULTS
  Actin FS, PTT-A, and Cephascreen were prolonged for FVIII level at 60%, 40%, and 40% respectively, FIX at 50%, 25%, and 35%, and FXI at 60%, 20%, and 50%. PTT-A showed the same sensitivity and specificity as Cephascreen to LA. Actin FS and PTT-A appeared less suitable to monitor UFH regarding the CLSI criteria.
  
  
  CONCLUSIONS
  Cephascreen fulfilled the CLSI performance criteria, with a good compromise in terms of sensitivity to factor deficiency and with a substantial reduction of complementary analysis in our routine practice.
authors.affiliation: Laboratory of Hematology and Haemostasis, Centre Hospitalier Universitaire Brugmann, Brussels, Belgium. laurence.rozen@chu-brugmann.be
authors.forename: Laurence
authors.initials: L
authors.lastname: Rozen
authors.forename: Florian
authors.initials: F
authors.lastname: Copette
authors.forename: Denis F
authors.initials: DF
authors.lastname: Noubouossie
authors.forename: Anne
authors.initials: A
authors.lastname: Demulder
mesh_terms: D006801:Humans; D007202:Indicators and Reagents; D010314:Partial Thromboplastin Time
chemical_list: D007202:Indicators and Reagents