In vitro proliferation of erythroid progenitors isolated from CD34⁺ cells.

CD34⁺ cells from 7 healthy donors and from patients with RARS (n = 7) or RA/RAEB (n = 13) were cultured for 10 days in proliferation medium and then switched to differentiation medium. Cells were counted every 3 days. Results are expressed as cumulative cell numbers (means ± SD).