From: Proceedings 10th World Congress of Cryosurgery
Clonogenicity of hematopoetic progenitor cells - influence of storage conditions and cultural techniques

November 1998
W. Gebauer, E Fallgren-Gebauer, F Schunter Blood Center of the German Red Cross NSOB, Institute Oldenburg, Germany

Blood progenitor cell (bpc) products for transplantation of patients after high dose chemotherapy of malignant diseases is a growing field of interest in blood banks. The reconstitutive potential of these cells is determined by flow cytometry and also by cell culture techniques. For certain procedures reducing the number of malignant contaminating cells like immunological purging, it may be desirable to collect more than one apheresis product on consecutive days to get a safe transplantation dose. In these cases, storage conditions have to be used that preserve bpc of sufficient quality for transplantation.

We determined the clonogenic potential of CD34 positive cells using short term culture assays for apheresis, products that had been collected, to give bpc support after high dose chemotherapy of mamma carcinoma. Cell populations were analyzed directly after apheresis or following 1, 2 or 3 days of storage at 4C before further processing. Relative amounts (SD) of 8.7% (4.3), 10.1% (4.9), 8.9% (5.5), and 7.6% (1.2) led to a CFU-GM, respectively. A linear correlation (12 0.956) existed between CFU-GM and BFU-E in the analyzed apheresis products without demonstrable differences between groups. Analysis of clonogenic; potential of CD34 positive cells in apheresis products stored at 4C without agitation led to no demonstrable alteration during the first three days of storage concerning erythroid and granulocytic progenitor cells.

Furthermore, in consecutive transplantation situations using immunologically purged CD34 positive cells, we describe the impact of our cryoconservation procedure on generated CFU-GM. Characteristic differences concerning clonogenic potential of CD34 positive cells produced by variation of culture conditions are conserved when CFU-GM as a ftinction of enriched bpc before and after cryopreservation are analyzed.


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