PROPERTIES OF OPTICAL-DATA FROM ACTIVATED PARTIAL THROMBOPLASTIN TIMEAND PROTHROMBIN TIME ASSAYS

Changes in characteristics of optical transmittance data from coagulat ion assays were examined as a function of concentration of coagulation proteins or anticoagulants. Transmittance data were collected for act ivated partial thromboplastin time (APTT) and prothrombin time (PT) as says from: 1) plasmas prepared by mixing normal plasmas with deficient plasmas to give varying levels of coagulation proteins; 2) plasmas co ntaining added heparin; and 3) 200 specimen plasmas that were also ass ayed for fibrinogen, coagulation factors, and other components. Optica l profiles were characterized using a set of parameters describing ons et and completion of coagulation, magnitude of signal change, rate of coagulation and other properties. Results indicated that parameters ot her than those typically reported for APTT and PT are associated with individual deficiencies, but that diagnosis of specimen status on the basis of optical data is complex. These results suggest possibilities for expanded interpretation of PT/APTT optical data for clinical or re search applications.