Megakaryocytic Progenitors in Long Term Cultures from MDS Patients.

Introduction: bone marrow long-term cultures (LTC) have been reported to produce very poor adherent stromal layer in MDS, but there are not many studies about the behaviour of the progenitor cells in supernatant culture medium. In this study we report the results of megakaryocytic progenitors (CFU-MK) in the supernatant of LTC of patients with refractory anemia (RA).

Material and method: LTCs were performed to 11 RA patients and to 13 normal multiorgan donors as control. Bone marrow red cells were sedimented with 1% methyl-cellulose and seeded for LTC in 10ml flasks (Nalge Nunc International), with Iscover medium supplemented with horse serum, foetal calf serum, hydrocortisone and carbonic air, at a final concentration of 1x10⁶ per ml. Flasks were placed in an incubator for 8 weeks. Half culture medium volume was renovated weekly, cell counts and assays of CFU-MK (Megacult C, Stem Cell Technologies), were performed. CFU-MK colonies were separated in three groups, containing 3–20 cells, 21–50 cells and more than 50 cells. Student t-test was used for statistical comparisons.

Results: Are in the following table, expressed as mean + standard desviation. After the third week no colony growth was observed in normal such as in MDS. Growth of CFU-MK colonies containing more than 50 cells was higher in basal control bone marrow, no statistical differences were found in the rest of the cultures.

Discussion: No important difference was found in LTC supernatant CFU-MK in our RA patients, and this supports the idea that the stromal damage is more important, in the pathophysyology of MDS, than that of the stem cells.