The complex between activated protein C and protein C inhibitor: A clinically useful indicator of aortic aneurysms?

The concentration of the complex between activated protein C and the protein C inhibitor reflects the degree of activation of blood coagulation. A sandwich method has been devised that measures the complex concentration in blood plasma. A key feature of the method is that the catching monoclonal antibody recognizes a complex-dependent neoepitope in PCI, which is a prerequisite, since the concentration of uncomplexed PCI is ≈104-fold higher than that of the complex. In patients with atherosclerotic disease, those with aortic aneurysms exhibit a three-fold increase in complex concentration compared to that of normal subjects.