[Protein C dynamics in peripheral arterial occlusive diseases and myocardial infarction: association of homozygous protein C deficiency with heterozygous dysplasminogenemia found among patients with deep vein thrombosis].

Protein C(PC) is the zymogen of a serine protease which regulates blood coagulation by inactivating activated blood coagulation factors V and VIII. We investigated the plasma level of PC in patients with deep vein thrombosis (DVT, n = 50), Buerger's disease (n = 34), arteriosclerosis obliterans (n = 37) and myocardial infarction (n = 17). PC in plasma was determined by rocket immunoelectrophoresis using a monospecific anti-PC antiserum raised in rabbits. Our study indicated that only in DVT the level of PC was decreased in comparison with the normal control (p less than 0.05). This decrease may be accounted for by increased utilization of PC for the regulation of continuously activated blood coagulation mechanism possibly ongoing in patients with DVT. On the other hand, among the patients with the DVT, we found a homozygous PC deficiency combined with a heterozygous dysplasminogenemia in a 22-year old male who had been suffering from recurrent venous thrombosis since the age of 14. Although the homozygous form of PC deficiency has been reported to be closely associated with fatal thrombotic disorders including purpura furminans during the neonatal period, the patient reported here had surprisingly survived the neonatal period and the childhood without any clinical manifestation relevant to thrombosis.