title: Reduction of antithrombin III, protein C, and protein S levels and activated protein C resistance in polycythemia vera and essential thrombocythemia patients with thrombosis.
abstract: Patients with polycythemia vera (PV) or essential thrombocythemia (ET) show a high frequency of thrombosis. The reduction of hematocrit after phlebotomy and normalization of platelet counts do not completely eliminate thrombotic risk. Some preliminary studies reported a reduction in the concentration of natural anticoagulants (NA) in this group of patients. For this reason we evaluated protein S (PS) total antigen, antithrombin III (AT III), and protein C (PC) activity in 81 patients with chronic myeloproliferative disorders (33 with PV and 48 with ET). Data were compared with those obtained in 70 healthy sex- and age-matched subjects. Fifty-seven percent of patients (46 out of 81) showed one or more thrombotic episodes at diagnosis or during follow-up. Interestingly, we found a NA deficit in 43.5% of patients with thrombosis versus only 5.7% in the group of patients without thrombosis. These results may suggest new interpretations about the pathogenesis of thrombosis in PV or ET patients.
authors.affiliation: Division of Hematology, Hospital A. Sclavo, Siena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bucalossi
authors.forename: G
authors.initials: G
authors.lastname: Marotta
authors.forename: C
authors.initials: C
authors.lastname: Bigazzi
authors.forename: P
authors.initials: P
authors.lastname: Galieni
authors.forename: E
authors.initials: E
authors.lastname: Dispensa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020152:Antithrombin III Deficiency; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D020151:Protein C Deficiency; D018455:Protein S Deficiency / Q000209:etiology*; D011655:Pulmonary Embolism / Q000097:blood / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D012306:Risk; D012907:Smoking / Q000453:epidemiology; D013920:Thrombocythemia, Essential / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D013927:Thrombosis / Q000097:blood / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology