Dexamethasone increases the numbers of EBs generated in cultures of NDs but not of PV patients. Numbers (at days 11 and 13; A) and representative maturation profiles and morphology (at day 13; B) of EBs generated in liquid cultures stimulated with growth factors with or without dexamethasone (DXM) by MNCs from NDs8 or from PV patients homozygous (H; n = 3) or heterozygous (He; n = 13) for the JAK2V617F mutation. Magnification ×40. Forward-scatter/side-scatter analyses and propidium iodide staining were comparable (∼ 10%-15% propidium iodide–positive cells) in all cultures analyzed and are not shown. P values are provided when differences between ND and PV were statistically significant. Statistical analyses of the FACS profiles are presented in Table 2. Differential counts of cultured cells (by morphology) are presented in panel C. The different populations are color coded: blue for non-EBs; red for Pro-EBs; and green, blue, and yellow for basophilic (Bas), polychromatic (Poly), and orthochromatic (Ortho) EBs, respectively.
