A new method to measure plasma levels of activated protein C in complex with protein C inhibitor in patients with acute coronary syndromes.

摘要

Our newly devised immunofluorometric sandwich assay for measuring plasma concentrations of activated protein C (APC) in complex with protein C inhibitor (PCI) was compared with testing for conventional markers of myocardial damage CKMB (creatine kinase MB), TNI (troponin I) and hypercoagulability (D-dimer, TAT) in 76 patients with suspected myocardial infarction (MI). APC-PCI complex levels in samples drawn on admission did not correlate with CKMB in the simultaneously drawn sample but correlated closely with maximal CKMB, which reflects MI size (r = 0.52). The areas under the receiver operating characteristics (ROC) curves calculated for the APC-PCI complex results obtained upon admission did not differ significantly from the corresponding values for CKMB, TNI or TAT. Our results show that in patients at risk for MI, the APC-PCI concentration is a sensitive and independent marker that can identify a subgroup of MI patients with normal CKMB but an increased APC-PCI level upon admission. It remains to be determined whether these patients would benefit from early intensive anticoagulant treatment.