PROBLEMS OF ORAL ANTICOAGULATION IN AN ADULT WITH HOMOZYGOUS PROTEIN-C DEFICIENCY AND LATE ONSET OF THROMBOSIS

We describe a 57-year-old woman with homozygous protein C deficiency a nd mild thrombotic manifestations consisting of three spontaneous dist al deep vein thromboses occurring after the age of 45. Previous surger y and pregnancies had been uneventful. Low but detectable protein C an tigen and activity levels (both 20%) were discovered on the occasion o f skin necrosis induced by oral anticoagulation. This therapy was inte rrupted because of skin necrosis and several episodes of disseminated intravascular coagulation (DIC) at the initiation of treatment despite a cautious protocol. No recurrent thromboembolic event has occurred i n our patient using prophylactic doses of low molecular weight heparin for 24 months. New therapeutic approaches might be the administration of low molecular weight heparin or oral anticoagulation associated wi th protein C replacement in the induction period. This case reflects t he variability of expression of protein C deficiency as well as the po tential hazards of antivitamin K anticoagulation in this disorder.