title: Circulating hematopoietic progenitor cells predict survival in patients with myelofibrosis with myeloid metaplasia.
abstract: OBJECTIVE
  The levels of circulating hematopoietic progenitor cells are often increased in myelofibrosis with myeloid metaplasia (MMM). The prognostic relevance of this phenomenon is largely unknown.
  
  
  METHODS
  We determined the number of circulating myeloid (CFU-GM), erythroid (BFU-E), and pluripotent (CFU-GEMM) progenitors, in 110 patients with MMM at diagnosis using a semi-solid colony assay. Overall survival was investigated by plots of the Kaplan-Meier estimator; known risk factors and the number of circulating progenitor cells were tested by univariate and multiple Cox regression analysis.
  
  
  RESULTS
  Univariate analysis showed that hemoglobin concentration (p=0.019), CFU-GM (p< 0.0001), BFU-E (p=0.002), and age (p=0.002) predicted survival. Numbers of circulating CFU-GM above the 75th percentile were associated with a significantly shorter survival than were CFU-GM levels at or below the 75th percentile (27 vs. 74 months, p=0.0007). Similarly, high numbers of BFU-E in peripheral blood (> 75th percentile) predicted a shorter survival (33 vs. 74 months; p=0.007). When myeloid and erythroid progenitor cells were calculated separately in the multiple Cox regression analysis, both CFU-GM (hazard ratio 2.8, 95% CI, 1.35 to 5.93) and BFU-E (hazard ratio 2.57, 95% CI, 1.26 to 5.21) numbers above the 75th percentile were independent adverse prognostic factors in our patients.
  
  
  CONCLUSIONS
  High levels of circulating myeloid and erythroid progenitor cells are novel risks factors in patients with MMM. The assessment of hematopoietic progenitor cells may be useful to determine risk-adjusted treatment strategies.
authors: Department of Internal Medicine I, Division of Hematology, University of Vienna, Vienna, Austria.
authors: Verena
authors: V
authors: Sagaster
authors: Eva
authors: E
authors: Jäger
authors: Ansgar
authors: A
authors: Weltermann
authors: Ilse
authors: I
authors: Schwarzinger
authors: Heinz
authors: H
authors: Gisslinger
authors: Klaus
authors: K
authors: Lechner
authors: Klaus
authors: K
authors: Geissler
authors: Leopold
authors: L
authors: Oehler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001772:Blood Cell Count; D003114:Colony-Forming Units Assay; D015672:Erythroid Precursor Cells; D005260:Female; D005500:Follow-Up Studies; D006412:Hematopoietic Stem Cells; D006801:Humans; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D022423:Myeloid Cells; D010976:Platelet Count; D039904:Pluripotent Stem Cells; D055728:Primary Myelofibrosis / Q000097:blood* / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D017701:Reticulocyte Count; D013163:Splenomegaly / Q000097:blood; D016019:Survival Analysis