title: International collaborative study for the calibration of a proposed international standard for thromboplastin, rabbit, plain.
abstract: BACKGROUND
  A preparation of rabbit brain thromboplastin, provisionally coded 04/162, is proposed as a candidate for the World Health Organization (WHO) International Standard (IS) for thromboplastin (rabbit, plain), meant to replace the IS coded RBT/90 (rabbit, plain), stocks of which are now exhausted.
  
  
  RESULTS
  The preparation was calibrated in an international collaborative study involving 21 laboratories from 13 countries and the calibration was performed against the existing WHO-IS (i.e. rTF/95 and OBT/79) and other Certified Reference Materials from the Institute for Reference Materials and Measurements of the European Commission (i.e. CRM149 S) and from the European Action on Anticoagulation (i.e. EUTHR-01). An additional candidate rabbit brain thromboplastin coded as 04/106 was also included in the study. On the basis of predefined criteria (the within- and between-laboratory precision of the calibration and the conformity to the calibration model), 04/162 was the preferred candidate.
  
  
  CONCLUSIONS
  The assigned International Sensitivity Index value was 1.15 and the inter-laboratory SD and coefficient of variation were 0.057% and 4.9%, respectively.
authors.affiliation: Department of Internal Medicine, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, University and IRCCS Ospedale Maggiore, Mangiagalli and Regina Elena Foundation, Milan, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Chantarangkul
authors.forename: A M H P
authors.initials: AM
authors.lastname: van den Besselaar
authors.forename: E
authors.initials: E
authors.lastname: Witteveen
authors.forename: A
authors.initials: A
authors.lastname: Tripodi
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002138:Calibration; D006490:Hemostatics / Q000302:isolation & purification / Q000592:standards*; D006801:Humans; D007391:International Cooperation; D019934:International Normalized Ratio / Q000592:standards*; D011517:Prothrombin Time / Q000592:standards*; D011817:Rabbits; D012015:Reference Standards; D013925:Thromboplastin / Q000302:isolation & purification / Q000592:standards*; D014944:World Health Organization
chemical_list: D006490:Hemostatics; D013925:Thromboplastin