The effects of non-cryopreservation on colony formation of committed progenitor cells of bone marrow.

Bone marrow from five prospective candidates for autologous bone marrow transplantation was subjected to short-term non-cryopreservation at room temperature, and mononuclear cell counts, cellular viability, CFU-GM, CFU-E, BFU-E and CFU-Mk were tested on days 0, 1, 2, 3, 5 and 7 of preservation. On day 5, mononuclear cell counts were over 60% with cellular viability of approximately 80%, and the number of CFU-GM colonies remained at approximately 45% of the original value. Decreases in the numbers of CFU-E, BFU-E and CFU-Mk colonies, however, were more rapid. On the average, 50% preservation could be maintained for only 2 days. Thus the common belief that the CFU-GM assay is the most reliable parameter for qualifying the marrow inoculum in marrow transplantation can be challenged. We suggest that CFU-E, BFU-E and CFU-Mk are more sensitive with CFU-Mk being the most reliable. Judged from the decreasing numbers of CFU-Mk colonies, 48 hours appears to be the maximum period for non-cryopreservation of marrow under conditions of the study at room temperature. Vulnerabilities of marrow progenitors seem to differ from cell lineage to cell lineage, and this must be taken into careful consideration in pursuing marrow transplantation.