Widespread damage to the endothelium causes an increase in clotting. This can lead to DIC, where fibrin forms inside the microvasculature and causes multiple organ failure. This renders the rest of the blood unable to clot, with obvious consequences.
Precursor to this is a gradual fall in the platelet levels - another diagnostic indicator in PET. There is generally a rise in levels of von Willebrand Factor (a sign of endothelial damage).
Last reviewed 01/2018