Usefulness of IMI and HPC of Sysmex SE-9000, and IRF and HFR of Sysmex R-3000 to Refine Apheresis Timing of Peripheral Blood Stem Cell Harvest

Kang, Yoon Hee; Park, Chan Jeoung; Kim, Sang Cheol; Kwon, Su Jin; Chi, Hyun Sook; Kim, Shin; Kim, Sung Bae; Kim, Sang We; Suh, Cheol Won; Kim, Sang Hee

Abstract

BACKGROUND: The Sysmex SE-9000 and R- 3000 automated cell counters provide estimates of immature cells referred to as immature myeloid information (IMI), hematopoietic progenitor cells (HPC), immature reticulocyte fraction (IRF) as high and medium fluorescent reticulocytes, and high fluorescence ratio (HFR) as high fluorescent reticulocytes. The aim of this study was to evaluate whether these parameters were useful to refine apheresis timing of peripheral blood stem cell (PBSC) harvest. METHOD: For 140 peripheral blood harvest procedures of 26 patients, pre-harvest peripheral blood (PB) WBC, mononuclear cells (MNC), IMI, HPC, CD34-positive cells, reticulocyte (%, number), IRF and HFR were tested and compared with harvested CD34-positive cell content.
RESULTS
Correlation coefficients between pre-harvest WBC, MNC, IMI, HPC, CD34-positive cells, reticulocyte %, reticulocyte number, IRF and HFR of PB and harvested CD34-positive cell content were 0.15, 0.06, 0.60, 0.78, 0.77, 0.004, 0.06, 0.28 and 0.40. Applying the criteria IMI 300X10degrees/L, HPC 5X10degrees/L and CD34-positive cells 5X10derees/L of PB on the first day of 30 cycles of harvests, positive predictive value to predict the mean CD34+ cell count over 0.5X106/kg per one leukapheresis and negative predictive value to predict the mean CD34+ cell count less than 0.5X10derees/kg per one leukapheresis were 73.3%/93.3%, 57.8%/90.9% and 78.6%/ 93.7% respectively.
CONCLUSION
Pre-harvest PB IMI and HPC of Sysmex SE-9000 are comparable with PB CD34- positive cells in terms of correlation with harvested CD34-positive cell content. For PB IMI and HPC are simple, inexpensive and rapid to get results, PB IMI and HPC are useful to refine apheresis timing of PBSC harvests and to screen poor-mobilizers.