The New Sysmex XN-2000 Automated Blood Cell Analyzer More Accurately Measures the Absolute Number and the Proportion of Hematopoietic Stem and Progenitor Cells Than XE-2100 When Compared to Flow Cytometric Enumeration of CD34+ Cells

The gold standard to count circulating hematopoietic stem and progenitor cells (HPCs) is to enumerate CD34+ cells by using flow cytometry [1, 2]. XE-2100 (Sysmex, Kobe, Japan), a currently used hematology analyzer, can be used to quantify HPCs, generating counts that reportedly correlate with those obtained using flow cytometric analysis of CD34+ cells; however, XE-2100 HPC counts were 1.86-fold higher than those calculated by flow cytometry [3]. The recently launched XN-2000 (Sysmex) can also be used to quantify HPCs, but its performance on HPC counts has not been evaluated. We assessed the HPC counting performance of XE-2100 and XN-2000 and compared them to CD34+ cell counts by flow cytometry. © The Korean Society for Laboratory Medicine.