title: Activation of the protein C pathway in hereditary thrombophilia.
abstract: Levels of free activated protein C are a measure of the activation of the protein C pathway in vivo. The aim of this study was to establish if the protein C pathway is triggered in familial thrombophilia and if activated protein C levels correlate with type of defect or symptoms. We measured activated protein C in 133 patients with a deficiency of antithrombin (n = 31), protein C (n = 24) or protein S (n = 27) or with resistance to activated protein C (n = 51). Levels of activated protein C were evaluated also in 97 healthy individuals. Results indicate that the levels of activated protein C are higher in patients who have experienced a thrombotic event than in patients who have not and that 71% of patients with levels of activated protein C above the normal reference range had had a venous thromboembolic event. We conclude that the protein C pathway is triggered in patients with thrombophilia and that in symptomatic patients, activated protein C levels are increased and may reflect heightened coagulation activation and scavenging through the protein C pathway.
authors.affiliation: Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, I.R.C.C.S. Maggiore Hospital, University of Milano, Italy. faioni@imiucca.csi.unimi.it
authors.forename: E M
authors.initials: EM
authors.lastname: Faioni
authors.forename: F
authors.initials: F
authors.lastname: Franchi
authors.forename: D
authors.initials: D
authors.lastname: Asti
authors.forename: P M
authors.initials: PM
authors.lastname: Mannucci
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011486:Protein C / Q000378:metabolism*; D019851:Thrombophilia / Q000097:blood*
chemical_list: D011486:Protein C