The ECLAP Investigators are listed in Appendix 1.
The haematocrit and platelet target in polycythemia vera
Article first published online: 8 DEC 2006
British Journal of Haematology
Volume 136, Issue 2, pages 249–259, January 2007
How to Cite
Di Nisio, M., Barbui, T., Di Gennaro, L., Borrelli, G., Finazzi, G., Landolfi, R., Leone, G., Marfisi, R., Porreca, E., Ruggeri, M., Rutjes, A. W. S., Tognoni, G., Vannucchi, A. M., Marchioli, R. and the European Collaboration on Low-dose Aspirin in Polycythemia Vera (ECLAP) Investigators (2007), The haematocrit and platelet target in polycythemia vera. British Journal of Haematology, 136: 249–259. doi: 10.1111/j.1365-2141.2006.06430.x
This study was presented at the 45th annual meeting of the American Society of Hematology, San Diego, CA, December 2003.
- Issue published online: 8 DEC 2006
- Article first published online: 8 DEC 2006
- Received 22 August 2006; accepted for publication 18 October 2006
- polycythemia vera;
- platelet count
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 × 109/l) we encountered in our population had an impact on the outcome of PV patients treated by current therapeutic strategies.