DETERMINING THE OPTIMAL TIME FOR PERIPHERAL-BLOOD STEM-CELL HARVEST BY DETECTING IMMATURE CELLS (IMMATURE LEUKOCYTES AND IMMATURE RETICULOCYTES) USING 2 NEWLY DEVELOPED AUTOMATIC CELL ANALYZERS

To determine the optimal time of peripheral blood stem cell harvest (P BSCH), we evaluated the usefulness of the detection of immature hemato poietic cells (immature leukocytes and reticulocytes) using newly deve loped automatic cell analyzers, and compared the results with those-of conventional CD34 measurement by flow cytometry (FCM). The presence o f immature leukocytes and reticulocytes was calculated as immature leu kocyte information (IMI)-positive rate and high fluorescence reticuloc yte (HFR)-positive rate by multi-item autoanalyzers. Both the IMI-posi tive rate and HFR-positive rate positively correlated with the CD34-po sitive rate and was more highly correlated with the colony forming uni ts-mixed (CFU-Mix) count in peripheral blood. In addition, they positi vely correlated not only with the CD34-positive rate, but also with th e colony forming units-granulocyte/macrophage (CFU-GM) count and CFU-M ix count in harvested stem cell juice. These findings imply that the p arameters of IMI and HFR could be used for determining the optimal tim e of PBSCH, and could also be useful for quantifying stem cells. (C) 1 997 Elsevier Science Ireland Ltd.