REPLACEMENT THERAPY WITH A MONOCLONAL-ANTIBODY PURIFIED PROTEIN-C CONCENTRATE IN NEWBORNS WITH SEVERE CONGENITAL PROTEIN-C DEFICIENCY

Protein C replacement therapy with a monoclonal antibody purified, vir us inactivated protein C concentrate was carried out in nine infants ( three male, six female) with severe congenital protein C deficiency an d life-threatening purpura fulminans and/or thrombosis associated with disseminated intravascular coagulation (DIG). Eight infants were homo zygous for protein C deficiency; one was a compound heterozygote. The treatment period varied from 22 days to three years. The half-life of protein C was found to be as short as two to three hours during activa tion of the coagulation system, increasing to approximately ten hours after stabilization. During the acute phase, protein C levels of 0.10 to 0.25 IU/mL were associated with elevated markers of coagulation act ivation indicating DIG, while protein C levels greater than 0.25 were associated with normalization of coagulation markers. No product-relat ed side effects were reported. Episodes of bleeding or purpura recurre d in all patients who were switched to oral anticoagulant therapy, nec essitating reinstatement of protein C replacement therapy, either as n eeded to control symptoms, or on a long-term prophylactic schedule, al one or in addition to oral anticoagulation. Home treatment with protei n C concentrate allowed a near-normal life-style for patients who othe rwise would be hospitalized for long periods of time.