Summary
Protein C was measured by means of enzyme-linked immunosorbent assay (ELISA) in plasmas
from 58 normal subjects, 39 patients with disseminated intravascular coagulation (DIC)
and 5 patients with thrombotic thrombocytopenic purpura (TTP). Protein C levels ranged
from 69.7 to 163.6% (95% confidence limits) in normal subjects. In patients with DIC,
protein C concentrations were significantly decreased, with a geometric mean value
of 42.1%. Protein C concentration was positively correlated with plasma prothrombin,
antithrombin III and serum pseudocholinesterase, and was negatively correlated with
von Willebrand factor antigen (vWF: Ag) and vWF: Ag/factor VIII ratio. These findings
suggest that low protein C concentrations in DIC mean a consumption of protein C probably
due to its activation by thrombin and/or impaired liver synthetic function. In patients
with TTP, protein C levels were normal with a geometric mean value of 116.7%, indicating
that the pathophysiology of TTP is quite different from that of DIC.
Keywords
Protein C - Disseminated intravascular coagulation - Thrombotic thrombocytopenic purpura
- Enzyme-linked immunosorbent assay (ELISA) - von Willebrand factor
