ACTIVATED PARTIAL THROMBOPLASTIN TIME REAGENTS - AN EVALUATION

Nine automated, activated partial thromboplastin time (APTT) reagents were evaluated on an automated coagulometer, in comparison with a manual reagent. The study consisted of three separate stages: 1) to choose a reagent that had a working stability between 4-degrees-C and 8-degrees-C for seven days and heparin sensitivity between 0 and 0.8 iu/ml; ii) assessment of sensitivity to specific factor deficiencies, particularly factors VIII, IX, XI and XII using standardised plasma serially diluted with factor-deficient plasma; and iii) assessment of sensitivity to the presence of a lupus anticoagulant, from a known positive panel. Only one reagent fulfilled all the essential criteria as an acceptable replacement for the manual reagent.