Usefulness of the IMI Channel of Sysmex SE-9000(TM) Automated Hematology Analyzer Predicting the Optimal Timing of Peripheral Blood Stem Cell Harvest / 임상검사와정도관리

BACKGROUND: An essential prerequisite for successful procurement of sufficient peripheral blood stem cells (PBSC) for engraftment is the optimal timing of collection. The Sysmex SE-9000 automated hematology analyzer provides the immature information (IMI) channel for the identification and counting PBSC. In this study, The optimal timing of PBSC collection was studied using IMI channel. METHODS: 193 peripheral blood stem cell collections were performed from 52 patients with hematologic disorders or solid tumors and 15 donors. Pre-harvest peripheral blood WBC, mononuclear cells (MNC) and IMI were tested and compared with CD34+ cell count and CFU-GM count of harvested products. RESULTS: Peripheral blood WBC and MNC count showed a weak correlation with CD34+ cell yield (r=0.38, P1x10(6)/kg with sensitivity of 88.7%. Positive and negative predictive values of IMI >465/microliter for CD34+ cell >1x10(6)/kg were 65.5% and 87.5%, respectively. CONCLUSIONS: The automated IMI might be used as a simple and efficient indicator of PBSC mobilization and applying variable cutoff values of IMI would be a useful tool to predict the optimal timing of PBSC collection.

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 / 대한혈액학회지

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.