Enrichment of normal progenitors in counter-flow centrifugal elutriation (CCE) fractions of fresh chronic myeloid leukemia leukapheresis products.

Abstract: Objectives : The aim of this study was to assess the suitability of a technique based on counter-flow centrifugal elutriation (CCE), which should allow one to enrich chronic myeloid leukemia (CML) patients' unstimulated native leukapheresis product (nLP) in CD34 + HLADR – cells and BCR-ABL negative cells. Methods : Six newly diagnosed CML patients were subjected to leukapheresis, and the products were subfractionated with the use of CCE. nLP and all fractions were studied for the presence of CD34 + cells and a proportion of BCR-ABL fluorescence in situ hybridization (FISH) + cells. Results : CCE fractions with a high flow rate contained the highest proportion of CD34 + cells [mean (SEM) 6.89% (3.88)]. However, CD34 + cells present in low-rate CCE fractions showed a higher proportion of HLADR – [49.6% (13.5 in 70 mL min -1 ) and 21.5% (11.6 in 110 mL min -1 )] than those in 170 mL min -1 [3.2% (2.5)] and ‘rotor off’[3.4% (1.9)]. This was associated with lower proportions of BCR-ABL FISH + [8.1% (4.8) and 1.9 (1.7)] and smaller BCR-ABL to ABL transcript ratios [0.58 ( 17 ) and 0.26 (0.08) in 70 and 110 mL min -1 ] fractions as compared to 140 and 170 mL min -1 fractions [21.6% (5.2) and 31.6% (15.3) for BCR-ABL FISH + cells and 0.75 (0.16) and 0.90 (0.24) for BCR - ABL / ABL ]. Fractions with the lowest proportions of BCR - ABL -positive cells and the lowest BCR - ABL / ABL transcript ratios (110 mL min -1 ) contained from 1.3 × 10 6 to 82.7 × 10 6 (median: 3.97 × 10 6 ) CD34 + cells. Conclusions : In the present study we have shown that CCE may be used effectively to obtain nLP fractions enriched in normal hematopoietic progenitors. [ABSTRACT FROM AUTHOR]