Šefer, D. (6603146747)D. (6603146747)ŠeferBižić-Radulović, S. (57192677013)S. (57192677013)Bižić-RadulovićKraguljac-Kurtović, N. (37037758700)N. (37037758700)Kraguljac-KurtovićBogdanović, A. (6603686934)A. (6603686934)BogdanovićČokić, V. (6507196877)V. (6507196877)ČokićMiljić, P. (6604038486)P. (6604038486)MiljićBeleslin-Čokić, B. (6506788366)B. (6506788366)Beleslin-ČokićKnežević, V. (56806620700)V. (56806620700)KneževićMitrović-Ajtić, O. (56586150800)O. (56586150800)Mitrović-AjtićLeković, D. (36659562000)D. (36659562000)LekovićGotić, M. (7004685432)M. (7004685432)Gotić2025-06-122025-06-122017https://doi.org/10.1111/ijlh.12564https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007319780&doi=10.1111%2fijlh.12564&partnerID=40&md5=f04d4c13c89a70f902d0e778069d9b33https://remedy.med.bg.ac.rs/handle/123456789/7141Introduction: Philadelphia-negative myeloproliferative neoplasms (Ph−MPN) are characterized by overproduction of one or more blood cell lines. Methods: We studied the proliferative characteristics of 91 patients with de novo Ph−MPN. Colony-forming cells (CFC) and endogenous colonies (EC), from bone marrow (BM) and/or peripheral blood (PB), were analyzed by colony assay based on methylcellulose. The level of circulating CD34+ cells was determined by flow cytometry. Results: The total number of PB CFC in primary myelofibrosis (PMF) was increased compared to the control sample (P < 0.01) and essential thrombocythemia (ET) (P < 0.05). The highest number of BM and PB EC was observed in polycythemia vera (PV) (P < 0.01). Increased levels of CD34+ cells characterized early-prefibrotic (57%) and advanced-fibrotic PMF (90%) as compared to PV (34%) and ET (32%) (P < 0.01). In the whole Ph−MPN group, the total number of PB CFC (P < 0.01), PB EC (P < 0.05), and CD34+ cells (P < 0.01) correlated with the degree of BM fibrosis. Higher levels of circulating CD34+ cells in PMF correlated with the total number of PB EC (P < 0.05) and degree of BM fibrosis (P < 0.01). Conclusions: Exploration of the PB proliferative characteristics of Ph−MPN on diagnosis may be helpful in revealing early-prefibrotic PMF. Monitoring the levels of circulating CD34+ cells may provide a sensitive indicator of fibrotic evolution in PV and PMF. © 2016 John Wiley & Sons LtdCD34⁺ cellscolony-forming cellsendogenous coloniesJAK2V617FMyeloproliferative neoplasm