title: Markers of endothelial and in vivo platelet activation in patients with essential thrombocythemia and polycythemia vera.
abstract: We investigated endothelial and in vivo platelet activation in a cohort of 52 patients with essential thrombocythemia (ET) and polycythemia vera (PV) before and after cytoreductive treatment, 22 healthy controls, and 17 patients with acute cerebrovascular ischemia (ACVI) and normal platelet counts. We measured platelet expression of CD62P and CD63 antigens and levels of soluble vascular cell adhesion molecule 1 (sVCAM-1). We found increased in vivo platelet activation in all patients with ET and PV, both before and after cytoreductive treatment, compared with controls. In patients with arterial thrombosis, platelet expression of CD62P, and in patients with erythromelalgia, expression of both markers was higher compared with expression in patients without thrombotic complications. In patients with ET and PV before and after treatment, sVCAM-1 expression was increased compared with expression in controls but also compared with expression in patients with ACVI and normal platelet counts. In patients with arterial thrombosis and erythromelalgia, in vivo platelet activation correlated with the level of sVCAM-1. Our findings indicated that in vivo platelet activation reflects intrinsic platelet defects in patients with ET and PV, persists after cytoreductive treatment, and results in endothelial damage, probably through release of angiogenic factors and/or activation of white blood cells.
authors.affiliation: Laboratory Hematology and Transfusion Medicine, Medical School, University of Patras, Patras GR-26110, Greece. makara@med.upatras.gr
authors.forename: Marina
authors.initials: M
authors.lastname: Karakantza
authors.forename: Nikolaos C
authors.initials: NC
authors.lastname: Giannakoulas
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Zikos
authors.forename: George
authors.initials: G
authors.lastname: Sakellaropoulos
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kouraklis
authors.forename: Anthi
authors.initials: A
authors.lastname: Aktypi
authors.forename: Ioannis C
authors.initials: IC
authors.lastname: Metallinos
authors.forename: Eleni
authors.initials: E
authors.lastname: Theodori
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Zoumbos
authors.forename: Alice
authors.initials: A
authors.lastname: Maniatis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000097:blood; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood / Q000188:drug therapy; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000473:pathology* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D019007:P-Selectin / Q000097:blood; D015539:Platelet Activation; D010980:Platelet Membrane Glycoproteins; D011087:Polycythemia Vera / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D060149:Tetraspanin 30; D013920:Thrombocythemia, Essential / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D013927:Thrombosis / Q000209:etiology; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood
chemical_list: D015703:Antigens, CD; D000970:Antineoplastic Agents; D015415:Biomarkers; C554586:CD63 protein, human; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D019010:Vascular Cell Adhesion Molecule-1