Thrombosis and haemostasis
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Nitric oxide derivatives and soluble plasma selectins in patients with myeloproliferative neoplasms.
Essential thrombocythaemia (ET) and polycythaemia vera (PV) are characterised by a high incidence of thrombotic complications due to high-shear stress of the vessel wall, blood hyperviscosity and hypoxaemia, all factors responsible for chronic endothelial dysfunction and platelet and leukocyte activation. We evaluated the activation status of vascular cells in 18 consecutive ET and 14 PV patients by measuring the plasma levels of the nitric oxide derivatives (NOX) (i.e. nitrites and nitrates) and of soluble selectins of platelet (P-selectin), endothelial cell (P-selectin and E-selectin) and leukocyte (L-selectin) origin. The effect of hydroxyurea (HU) therapy on these parameters was also investigated. ⋯ In the multivariate analysis, NOX predicted increased levels of E-selectin in ET, but not in PV patients. Our data demonstrate that ET and PV are characterised by an altered pattern of soluble selectins and NOX. HU-mediated increase of NOX levels could represent an additional antithrombotic mechanism of this drug.