[Evaluation of single-stage methods of studying the activity of factor VIII]

Accurate diagnosis of coagulopathies related to changed factor VIII activity, studies of specific activities of antihemophilic cryoprecipitate globulin used for hemostatic correction in patients, and monitoring of therapy efficacy are impossible without a reproducible, sensitive, standard, and available method. The authors have compared two single-stage methods developed by Soviet scientists: that by V. P. Baluda et al. and that by L. P. Papayan and P. V. Khrolova. Both methods have proved sufficiently sensitive and capable to detect factor VIII deep deficiency, but L. P. Papayan and P. V. Khrolova's modification was found higher reproducible, and therefore chosen for further investigation in order to standardize it. Besides the conditions of reproducing the method, reference plasma, substrate plasma deficient for factor VIII, and partial thromboplastin are to be standardized.