[Immunologic and functional protein C determination in various internal diseases]

A new practicable and precise functional protein C evaluation test is based on the activation of protein C by a snake venom activator and determination of PC activity by its property to prolong the aPTT in a clotting assay (VK = 1.9% and 4% for intra- and interassay variance respectively). In 40 healthy controls there was a good correlation (r = 0.74) between the functional and immunological (ELISA) evaluation. In 123 patients with both evaluation methods but more pronounced with the measurement of the protein C activity a significant protein C deficiency was found in the patient groups with disseminated solid tumors, inflammatory diseases and myocardial infarction. Besides detection of hereditary PC deficiency Type II (generation of functionally abnormal PC) the functional assay profits by recording PC inhibitor complexes and otherwise dysfunctional PC in DIC. Thus, in patients with hematological neoplasias, only protein C activity was significantly decreases. Decrease of PC activity was more pronounced compared to PC Ag in liver disease indicating synthesis of functionally deficient PC, and in oral anticoagulant treatment due to detection of PIVKA-PC.