The clonogenic potential of selected CD34+ cells from patients with MDS appear preserved when tested ex vivo

Our aim was to examine in 17 patients with MDS the effects of PMA activated and non-activated autologous lymphocytes on selected bone marrow CD34+ progenitors, in dose response studies. We used a double layer culture technique. Compared with controls, there was no difference in the colony growth promoting capacity of autologous PMA stimulated or unstimulated blood lymphocytes from MDS patients. In addition, similar to control studies, increasing numbers of lymphocytes, (0, 1 × 105, 1 × 106) led to a corresponding increase in the number of CFU-GM (p = 0.04). We conclude that MDS blood mononuclear cells have the ability to stimulate colony growth of autologous CD34+ cells while these selected progenitors show a proliferative capacity that is similar to normal when they are isolated from the bone marrow accessory cells.