Summary
Protein C, an antithrombotic protein, was measured immunologically in 299 patients
with clinical conditions associated with a high frequency of venous or arterial thromboembolism.
The mean protein C antigen (PC: Ag) level was high for 48 patients with ischemic heart
disease and, to a lesser extent, for 95 diabetics. In 28 patients with thrombotic
strokes, 48 patients with proximal deep-vein thrombosis and in 80 patients with localized
or metastatic tumors, mean PC: Ag was normal. Comparison of the pattern of changes
of PC: Ag levels with those of fibrinogen, orosomucoid and prothrombin in 21 patients
during the postoperative period and in 20 patients with active rheumatoid arthritis
ruled out the possibility that high PC: Ag is non-specific, acute-phase reaction to
inflammation, tissue injury or neoplastic growth. Therefore, high PC:Ag might be specifically
related to the thrombotic tendency of these patients, but the mechanism of such a
relationship remains to be clarified.
Key words
Protein C - Deep-vein thrombosis - Tumors - Stroke-diabetes - Ischemic heart disease
- Acute phase reactions
