PILOT EXPERIENCE IN DIAGNOSIS OF THROMBOP HILIA CAUSED BY ACTIVATED PROTEIN-C RESISTANCE

The authors describe the first in Russia cases of thrombophilia caused by factor Va resistance to activated protein C. This abnormality was diagnosed in 6 of 25 patients (24%) with recurrent early thrombosis. T he diagnosis was conducted according to a modified method implying the addition of protac (activator of protein C) to normal platelet poor p lasma (PPP) free of factor V containing 100% of protein C. Protac dose was adjusted to increase the activated partial thromboplastin time (A PTT) 2.4-2.8-fold in mixing PPP of tile examinee with plasma containin g activated protein C. The indices were estimated indicative of insuff icient prolongation of APTT in response to activated protein C. Of 6 p atients, 2 had apparent and 4 strong resistance to activated protein C . Treatment policy in this variant of thrombophylia is discussed.