Automated amidolytic method for evaluating the activated partial thromboplastin time compared with a conventional coagulation method.
We report studies of the validity and clinical application of a new amidolytic method for evaluating the activated partial thromboplastin time (APTT) compared with a conventional clotting method. The results with the two methods were well correlated for normal plasma and plasma from hemophilia patients. Congenital deficiencies of of the intrinsic coagulation pathway other than hypo- and dysfibrinogenemia detected by the amidolytic method agreed with those detected by the clotting APTT. The results with the two methods for plasma from patients under heparin treatment were statistically different, suggesting a lesser sensitivity of the amidolytic method to heparinization. The use of the amidolytic APTT reagent in combination with factor VIII and IX deficient plasma allowed the measurement of both factors. The results obtained with normal and hemophilic plasma were in agreement with those obtained with the one-stage clotting method in all except two occasions. Even though the amidolytic method demonstrated the presence of the lupus anticoagulant in the majority of tested samples of known lupus subjects, it was less sensitive to the abnormality than the clotting method.
Tripodi
A
A
A. Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milan, Italy.
Poggio
M
M
Scapellato
L
L
Mannucci
P M
PM
D000328:Adult; D000368:Aged; D001322:Autoanalysis; D001778:Blood Coagulation Disorders / Q000151:congenital; D001779:Blood Coagulation Factors / Q000032:analysis / Q000276:immunology; D001780:Blood Coagulation Tests; D002863:Chromogenic Compounds / Q000378:metabolism*; D005260:Female; D006467:Hemophilia A / Q000097:blood; D002836:Hemophilia B / Q000097:blood; D006801:Humans; D016682:Lupus Coagulation Inhibitor; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results
D001779:Blood Coagulation Factors; D002863:Chromogenic Compounds; D016682:Lupus Coagulation Inhibitor