{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T23:13:54Z","timestamp":1792192434029,"version":"4.4.0"},"reference-count":21,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,9,13]],"date-time":"2023-09-13T00:00:00Z","timestamp":1694563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Oncology Nurse Association (AEOP)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Hematology Reports"],"abstract":"<jats:p>Patients with polycythaemia vera (PV) are at increased risk of thrombosis and haemorrhages. Although hydroxyurea (HU) has been the frontline therapy for patients at high risk of vascular complications, about 25% of patients develop resistance\/intolerance to this therapy. The aim of this non-interventional, multicentre cohort study was to understand the clinical characteristics and HU treatment response of Portuguese PV patients. HU resistance\/intolerance was defined according to adjusted European LeukemiaNet (ELN) criteria. In total, 134 PV patients with a mean (SD) disease duration of 4.8 (5.0) years were included and followed up for 2 years. At baseline, most patients were \u226560 years old (83.2%), at high risk for thrombotic events (87.2%), and receiving HU therapy (79.1%). A total of 10 thrombotic events and 8 haemorrhagic events were reported, resulting in a 5-year probability of thrombo-haemorrhagic events of 17.2%. Haematocrit (p = 0.007), haemoglobin (p = 0.012) and MPN10 symptom score (12.0 (11.6) vs. 10.3 (9.1); p = 0.041) decreased significantly at the 24-month visit compared to baseline. Overall, 75.9% of patients met at least one of the adjusted ELN criteria for HU resistance, and 14.4% of patients remained on HU throughout the study. The results from this real-world study may help identify the subset of patients at higher risk for disease sequelae who may benefit from earlier second-line treatment.<\/jats:p>","DOI":"10.3390\/hematolrep15030056","type":"journal-article","created":{"date-parts":[[2023,9,13]],"date-time":"2023-09-13T05:31:28Z","timestamp":1694583088000},"page":"532-542","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Real-World Clinical Characterisation of Polycythaemia Vera Patients from a Prospective Registry in Portugal: Is Resistance to Hydroxyurea a Reality?"],"prefix":"10.3390","volume":"15","author":[{"given":"Maria","family":"Sarmento","sequence":"first","affiliation":[{"name":"Unidade Local de Sa\u00fade de Matosinhos, Hospital Pedro Hispano, 4464-513 Senhora da Hora, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marta","family":"Duarte","sequence":"additional","affiliation":[{"name":"Unidade Local de Sa\u00fade de Matosinhos, Hospital Pedro Hispano, 4464-513 Senhora da Hora, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Ponte","sequence":"additional","affiliation":[{"name":"Centro Hospitalar Lisboa Ocidental, Hospital de S\u00e3o Francisco Xavier, 1449-005 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juan","family":"Sanchez","sequence":"additional","affiliation":[{"name":"Centro Hospitalar Lisboa Ocidental, Hospital de S\u00e3o Francisco Xavier, 1449-005 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diana","family":"Roriz","sequence":"additional","affiliation":[{"name":"Funda\u00e7\u00e3o Champalimaud, 1400-038 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Funda\u00e7\u00e3o Champalimaud, 1400-038 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Jos\u00e9 Monteiro","family":"Silva","sequence":"additional","affiliation":[{"name":"Centro Hospitalar de Vila Nova de Gaia\/Espinho, 4434-502 Vila Nova de Gaia, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Judite","family":"Pacheco","sequence":"additional","affiliation":[{"name":"Centro Hospitalar de Vila Nova de Gaia\/Espinho, 4434-502 Vila Nova de Gaia, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gisela","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Centro Hospitalar do Baixo Vouga, 3810-164 Aveiro, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7702-237X","authenticated-orcid":false,"given":"Jorge","family":"Freitas","sequence":"additional","affiliation":[{"name":"Instituto Portugu\u00eas de Oncologia do Porto, 4200-072 Oporto, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"In\u00eas","family":"Costa","sequence":"additional","affiliation":[{"name":"Novartis Farma, Produtos Farmac\u00eauticos S.A., 2740-257 Porto Salvo, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0598-3013","authenticated-orcid":false,"given":"Daniel","family":"Br\u00e1s","sequence":"additional","affiliation":[{"name":"Novartis Farma, Produtos Farmac\u00eauticos S.A., 2740-257 Porto Salvo, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2391","DOI":"10.1182\/blood-2016-03-643544","article-title":"The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia","volume":"127","author":"Arber","year":"2016","journal-title":"Blood"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1038\/nature03546","article-title":"A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera","volume":"434","author":"James","year":"2005","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"595","DOI":"10.3109\/10428194.2013.813500","article-title":"Epidemiology of myeloproliferative neoplasms in the United States","volume":"55","author":"Mehta","year":"2014","journal-title":"Leuk. Lymphoma"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1111\/ejh.12256","article-title":"Epidemiology of myelofibrosis, essential thrombocythemia, and polycythemia vera in the European Union","volume":"92","author":"Moulard","year":"2014","journal-title":"Eur. J. Haematol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e366","DOI":"10.1038\/bcj.2015.95","article-title":"Blast transformation and fibrotic progression in polycythemia vera and essential thrombocythemia: A literature review of incidence and risk factors","volume":"5","author":"Cerquozzi","year":"2015","journal-title":"Blood Cancer J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1200\/JCO.2010.31.8436","article-title":"Philadelphia-negative classical myeloproliferative neoplasms: Critical concepts and management recommendations from European LeukemiaNet","volume":"29","author":"Barbui","year":"2011","journal-title":"J. Clin. Oncol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"103","DOI":"10.3324\/haematol.2016.152769","article-title":"Risk of thrombosis according to need of phlebotomies in patients with polycythemia vera treated with hydroxyurea","volume":"102","author":"Ramirez","year":"2017","journal-title":"Haematologica"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1599","DOI":"10.1002\/ajh.26008","article-title":"Polycythemia vera and essential thrombocythemia: 2021 update on diagnosis, risk-stratification and management","volume":"95","author":"Tefferi","year":"2020","journal-title":"Am. J. Hematol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1056\/NEJMoa1208500","article-title":"Cardiovascular events and intensity of treatment in polycythemia vera","volume":"368","author":"Marchioli","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1056\/NEJMoa035572","article-title":"European Collaboration on Low-Dose Aspirin in Polycythemia Vera, I. Efficacy and safety of low-dose aspirin in polycythemia vera","volume":"350","author":"Landolfi","year":"2004","journal-title":"N. Engl. J. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"794240","DOI":"10.1155\/2011\/794240","article-title":"The CYTO-PV: A Large-Scale Trial Testing the Intensity of CYTOreductive Therapy to Prevent Cardiovascular Events in Patients with Polycythemia Vera","volume":"2011","author":"Marchioli","year":"2011","journal-title":"Thrombosis"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1363","DOI":"10.1182\/blood-2011-10-387787","article-title":"Assessment and prognostic value of the European LeukemiaNet criteria for clinicohematologic response, resistance, and intolerance to hydroxyurea in polycythemia vera","volume":"119","author":"Pereira","year":"2012","journal-title":"Blood"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4098","DOI":"10.1200\/JCO.2012.42.3863","article-title":"Myeloproliferative neoplasm (MPN) symptom assessment form total symptom score: Prospective international assessment of an abbreviated symptom burden scoring system among patients with MPNs","volume":"30","author":"Emanuel","year":"2012","journal-title":"J. Clin. Oncol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1111\/j.1365-2141.2009.08019.x","article-title":"A unified definition of clinical resistance and intolerance to hydroxycarbamide in polycythaemia vera and primary myelofibrosis: Results of a European LeukemiaNet (ELN) consensus process","volume":"148","author":"Barosi","year":"2010","journal-title":"Br. J. Haematol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1421","DOI":"10.1007\/s00277-019-03654-6","article-title":"Polycythemia vera and hydroxyurea resistance\/intolerance: A monocentric retrospective analysis","volume":"98","author":"Demuynck","year":"2019","journal-title":"Ann. Hematol."},{"key":"ref_16","first-page":"557","article-title":"Symptoms, risk classification, and spleen size in JAK2 inhibitor-na\u00efve myelofibrosis: Implications for JAK2 inhibitor treatment","volume":"101","author":"Scherber","year":"2016","journal-title":"Haematologica"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1111\/bjh.13886","article-title":"Frequency and prognostic value of resistance\/intolerance to hydroxycarbamide in 890 patients with polycythaemia vera","volume":"172","author":"Kerguelen","year":"2016","journal-title":"Br. J. Haematol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/j.patbio.2004.02.007","article-title":"A prospective analysis of thrombotic events in the European collaboration study on low-dose aspirin in polycythemia (ECLAP)","volume":"52","author":"Finazzi","year":"2004","journal-title":"Pathol. Biol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1007\/s00277-015-2357-4","article-title":"Current and future treatment options for polycythemia vera","volume":"94","author":"Griesshammer","year":"2015","journal-title":"Ann. Hematol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1111\/ejh.13022","article-title":"Disease and treatment characteristics of polycythemia vera patients in Belgium: Results from a scientific survey","volume":"100","author":"Devos","year":"2018","journal-title":"Eur. J. Haematol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1016\/j.clml.2018.05.020","article-title":"Patient-Reported Outcomes Data From REVEAL at the Time of Enrollment (Baseline): A Prospective Observational Study of Patients With Polycythemia Vera in the United States","volume":"18","author":"Mesa","year":"2018","journal-title":"Clin. Lymphoma Myeloma Leuk."}],"container-title":["Hematology Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2038-8330\/15\/3\/56\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:49:58Z","timestamp":1760129398000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2038-8330\/15\/3\/56"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,13]]},"references-count":21,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["hematolrep15030056"],"URL":"https:\/\/doi.org\/10.3390\/hematolrep15030056","relation":{},"ISSN":["2038-8330"],"issn-type":[{"value":"2038-8330","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,13]]}}}