Blood Transfusion - 1 2020 (January-February)
Assessment of haematopoietic progenitor cell counting with the Sysmex® XN-1000 to guide timing of apheresis of peripheral blood stem cells
Authors:  Francesco Dima, Erika Barison, Martina Midolo, Fabio Benedetti, Giuseppe Lippi
Pages:  67-76
To cite this article:  Blood Transfus 2020; 18: 67-76
Doi:  10.2450/2019.0086-19
Published online:  25/07/2019

Background. Successful peripheral blood stem cell (PBSC) collection depends on optimal timing of apheresis, as usually determined by flow cytometry CD34-positive (+) cell count in peripheral blood (PB). Since this method is costly and labour-intensive, we evaluated the use of the Hematopoietic Progenitor Cell count programme on a Sysmex® XN haematologic analyser (XN-HPC) as a rapid and inexpensive alternative for predicting CD34+ cell count in PB samples.
Materials and methods. Haematopoietic progenitor cell and CD34+ cell counts were compared using 273 PB samples collected from 78 healthy donors and 72 patients who underwent PBSC transplantation. We assessed the effectiveness of the XN-HPC in safely predicting pre-harvest CD34+ counts. The most efficient cut-off values of XN-HPC were identified. We also evaluated the imprecision (coefficient of variation, CV) and functional sensitivity.
Results. Imprecision of the XN-HPC count was <6.3% on daily measurement of three levels of quality control material. Functional sensitivity was 8.9×106/L. A cut-off value of ≥62×106/L XN-HPC for multiple myeloma (MM) patients and ≥30×106/L for all other subjects had both 100% specificity and 100% positive predictive value for identifying samples with CD34+ cells ≥20×106/L. An XN-HPC threshold of <13×106/L identified pre-harvest CD34+ cell count <10×106/L with 100% sensitivity and 100% negative predictive value.
Discussion. The XN-HPC is a fast, easy and inexpensive test that can safely improve apheresis workflow thus possibly replacing other more expensive CD34 counts currently performed and promoting optimal timing of PBSC collection.
Keywords: haematopoietic progenitor cells, Sysmex® XN-1000 analyser, CD34-positive cells, apheresis, peripheral blood stem cell transplant.
Full Text Download Back
Share this article: