{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T14:05:31Z","timestamp":1791295531127,"version":"4.1.0"},"reference-count":38,"publisher":"American Society of Hematology","issue":"12","content-domain":{"domain":["ashpublications.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2011,9,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>Essential thrombocythemia (ET) and polycythemia vera (PV) are characterized by persistent platelet activation. The mechanisms involved in their clearance are poorly characterized. In the present study, we report that leukocytes were actively involved in platelet disposal in 51 patients with ET and 30 with PV, but not in 70 age- and sex-matched controls. The fraction of circulating neutrophils and monocytes that had phagocytosed platelets, as assessed by flow cytometry, was significantly higher in patients with PV or ET, independently of hydroxyurea treatment, than in controls. Platelet phagocytosis by circulating leukocytes was confirmed by confocal and electron microscopy. The lack of effect of hydroxyurea, which disrupts the P-selectin\/P-selectin glycoprotein ligand 1 (PSGL-1) interaction, suggests a P-selectin\u2013independent mechanism. This hypothesis was confirmed in an ad hoc animal model based on the in vivo injection of activated platelets from P-selectin+\/+ and P-selectin\u2212\/\u2212 mice. P-selectin expression was associated with an earlier and effective clearance of platelets by neutrophils. A second delayed, P-selectin\u2013independent phase actively involved monocytes. Our results suggest that phagocytic clearance of platelets by leukocytes occurs in PV and ET, possibly involving P-selectin\u2013dependent and -independent pathways, thus representing a novel mechanism to remove activated platelets from the circulation.<\/jats:p>","DOI":"10.1182\/blood-2011-02-337337","type":"journal-article","created":{"date-parts":[[2011,6,25]],"date-time":"2011-06-25T23:15:20Z","timestamp":1309043720000},"page":"3359-3366","update-policy":"https:\/\/doi.org\/10.1182\/blood.2019cm0000","source":"Crossref","is-referenced-by-count":55,"title":["Clearance of circulating activated platelets in polycythemia vera and essential thrombocythemia"],"prefix":"10.1182","volume":"118","author":[{"given":"Norma","family":"Maugeri","sequence":"first","affiliation":[{"name":"Unit of Autoimmunity and Vascular Inflammation and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simona","family":"Malato","sequence":"additional","affiliation":[{"name":"Hematology and Bone Marrow Transplantation Unit, Division of Regenerative Medicine, Gene Therapy and Stem Cells, Istituto Scientifico San Raffaele and Universit\u00e0 Vita-Salute San Raffaele, Milan, Italy; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eti A.","family":"Femia","sequence":"additional","affiliation":[{"name":"Medicina 3, Ospedale San Paolo, Dipartimento di Medicina, Chirurgia e Odontoiatria, Universit\u00e0 degli Studi di Milano, Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariateresa","family":"Pugliano","sequence":"additional","affiliation":[{"name":"Medicina 3, Ospedale San Paolo, Dipartimento di Medicina, Chirurgia e Odontoiatria, Universit\u00e0 degli Studi di Milano, Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lara","family":"Campana","sequence":"additional","affiliation":[{"name":"Unit of Autoimmunity and Vascular Inflammation 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