BLAST COLONY-FORMING CELLS IN UMBILICAL-CORD BLOOD - FREQUENCY AND CORRELATION TO OTHER HEAMOPOIETIC PROGENITORS

Umbilical cord blood has been suggested as a potential source of haemo poietic stem cells for clinical transplantation. Assay of stroma adher ent blast colony forming cells (CFU-BL), as a cell type that may predi ct marrow repopulation, has already been suggested to predict the outc ome of bone marrow transplantation. In the present experiments the fre quency of CFU-BL in plastic non adherent mononuclear cell fraction (PN AMNC) of umbilical cord blood was studied. If PNAMNC from cord blood w as co-incubated with a pre-established stromal layer from normal bone marrow a strict linear correlation between panned PNAMNC and blast col onies were observed. Frequency of CFU-BL in cord blood was significant ly lower than that in bone marrow. In cord blood, CFU-GEMM frequency w as found to be comparable to that of bone marrow, CFU-GM and BFU-E fre quency was reduced. A good correlation between CFU-BL and BFU-E freque ncy was found both in cord blood and bone marrow. On the other hand, i rrespective of their source, correlation between CFU-BL and CFU-GEMM o r CFU-GM was weak.