title: Activation of the tissue factor-dependent extrinsic pathway and its relation to JAK2 V617F mutation status in patients with essential thrombocythemia.
abstract: Thrombotic complications may occur in 7.6-29.4% of patients with essential thrombocythemia. According to the cellular theory, tissue factor (TF) activating extrinsic blood coagulation pathway is essential for the activation of blood clotting. The aim of the study was to evaluate the activation of the TF-dependent extrinsic pathway in patients with essential thrombocythemia, depending on the presence or absence of the Janus kinase 2 (JAK2) V617F mutation. The study included 74 newly diagnosed patients (F/M: 47/27; mean age 61 years) with essential thrombocythemia (Tefferi and Vardiman, Leukemia 2008; 22(1):14-22). Patients were diagnosed in the Department of Clinical Hematology and Hematological Malignancies University Hospital No. 2, Bydgoszcz, Poland. The control group consisted of 30 healthy volunteers (F/M: 17/13; mean age 49 years). The concentration and activity of TF and TF pathway inhibitor (TFPI) were measured using ELISA method. In patients with essential thrombocythemia, we observed a higher concentration of TF [median (Me) = 686.90 vs 164.28 pg/ml] and over 10-fold higher activity of TF (Me = 46.05 vs 4.01 pmol/l) when compared with the control group. We also reported significantly higher activity of TFPI compared with the control group (Me = 1.93 vs 1.78 U/ml). Moreover, a concentration of TFPI was significantly lower in patients with essential thrombocythemia with JAK2 V617F mutation as compared with patients without the mutation (Me = 1.90 vs 2.16 U/ml; P = 0.039639). Increased TF activity and concentration is responsible for higher procoagulant potential in patients with essential thrombocythemia. Reduced activity of TFPI in patients with essential thrombocythemia with JAK2 V617F mutation indicates an increased prothrombotic risk in this group of patients.
authors.affiliation: aDepartment of Hematology and Malignant Diseases of Hematopoietic System, Faculty of Medicine bDepartment of Pathophysiology, Faculty of Pharmacy cDepartment of Clinical Genetics, Faculty of Medicine, Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Poland.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Gadomska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Stankowska
authors.forename: Joanna
authors.initials: J
authors.lastname: Boinska
authors.forename: Alicja
authors.initials: A
authors.lastname: Bartoszewska-Kubiak
authors.forename: Olga
authors.initials: O
authors.lastname: Haus
authors.forename: Danuta
authors.initials: D
authors.lastname: Rość
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D009154:Mutation; D013920:Thrombocythemia, Essential / Q000150:complications / Q000235:genetics*; D013925:Thromboplastin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D008074:Lipoproteins; C051928:lipoprotein-associated coagulation inhibitor; D013925:Thromboplastin; C507924:JAK2 protein, human; D053614:Janus Kinase 2