CD34(-LEUKEMIA - A COMPARISON OF LABORATORY GRADE COLUMNS() CELL SELECTION IN CHRONIC PHASE CHRONIC MYELOID)

CD34 positive (CD34(+)) cell selection is increasingly used for a numb er of important applications including gene therapy studies, ex ville expansion and purging, However there are no data regarding the use of different technologies for CD34(+) cell selection in chronic myeloid l eukaemia (CR;IL), We therefore compared the performance of three labor atory grade CD34(+) selection columns (MiniMACS, Cellpro Ceprate LC an d Baxter Isolex 50), using CML chronic phase peripheral blood (PB) and bone marrow (BM). With different CML samples the CD34(+) purity from the three columns was equivalent, but comparing five paired samples th e Ceprate purity was greater than MiniMACS, at 92.5 and 80.9%, respect ively, P = 0.04. Combining results from paired and unpaired CML sample s, MiniMACS (n = 7) gave a higher CD34(+) yield than Ceprate LC (n = 8 ) or Isolex 50 (n = 4) with a mean of 51.1%, 24.3% and 13.2% respectiv ely, (P = 0.04 and 0.01), Cell Losses with all columns were similar, A ttempts to improve the yield from the Ceprate LC columns by modifying the method were unsuccessful, Following MiniMACS and Ceprate LC separa tion the clonogenic potentials of CD34(+) cells in the pre-and positiv e cell fractions were the same, The proportion of CD34(+)38(-) or CD34 (+)DR(-) cells was unchanged following column separation, These data s uggest that the MiniMACS column may be the best column for CD34(+) cel l selection in CML but these results must be confirmed using large sca le clinical columns once the MiniMACS column is licensed, It is possib le that variations in CD34(+) cell yields between the different column s reflect differences in antibody binding affinity to CR-IL cells, or differences in column technologies.