title: The haematocrit and platelet target in polycythemia vera.
abstract: Polycythemia vera (PV) is a chronic myeloproliferative disorder whose major morbidity and mortality are thrombohaemorragic events and progression to acute leukaemia or myelofibrosis. Whether the haematocrit and platelet count predict such complications remains unclear. The European Collaboration on Low-dose Aspirin in Polycythemia Vera prospective study included 1638 PV patients. A total of 164 deaths (10%), 145 (8.85%) major thrombosis and 226 (13.8%) total thrombosis were encountered during 4393 person-years follow-up (median 2.8 years). In time-dependent multivariable analysis, a haematocrit in the evaluable range of 40-55% was neither associated with the occurrence of thrombotic events, mortality nor with haematological progression in the studied population. The haematocrit of patients in the highest and lowest deciles at baseline was maintained within a narrow interval of haematocrit values ranging from 40% to 47% throughout follow-up. High platelet count was associated with a lower progression rate to acute leukaemia/myelofibrosis, whereas it had no significant relationship with thrombotic events or mortality. Our findings do not suggest that the range of haematocrit (<55%) and platelet counts (<600 x 10(9)/l) we encountered in our population had an impact on the outcome of PV patients treated by current therapeutic strategies.
authors.affiliation: Department of Medicine and Aging, School of Medicine, and Aging Research Centre, Ce S I, Gabriele D'Annunzio University Foundation, Chieti-Pescara, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Di Nisio
authors.forename: Tiziano
authors.initials: T
authors.lastname: Barbui
authors.forename: Leonardo
authors.initials: L
authors.lastname: Di Gennaro
authors.forename: Giovanna
authors.initials: G
authors.lastname: Borrelli
authors.forename: Guido
authors.initials: G
authors.lastname: Finazzi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Landolfi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Leone
authors.forename: Rosamaria
authors.initials: R
authors.lastname: Marfisi
authors.forename: Ettore
authors.initials: E
authors.lastname: Porreca
authors.forename: Marco
authors.initials: M
authors.lastname: Ruggeri
authors.forename: Anne W S
authors.initials: AW
authors.lastname: Rutjes
authors.forename: Gianni
authors.initials: G
authors.lastname: Tognoni
authors.forename: Alessandro M
authors.initials: AM
authors.lastname: Vannucchi
authors.forename: Roberto
authors.initials: R
authors.lastname: Marchioli
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007938:Leukemia / Q000097:blood; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011087:Polycythemia Vera / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D055728:Primary Myelofibrosis / Q000097:blood; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013927:Thrombosis / Q000209:etiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin