Accuracy of lymphocyte counts from UniCel DxH 800 in β-thalassemia/HbE patients having various numbers of nucleated red blood cells
Sunil Timilsena,1,3 Sakkarin Ardsiri,2 Surada Lerdwana,3 Krishna Das Manandhar,1 Kovit Pattanapanyasat,3 Egarit Noulsri4
1 Central Department of Biotechnology, Tribhuvan University, Kathmandu, Nepal
2 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
3 Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
4 Research Division, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Abstract
Background: The UniCel® DxH-800 is an automated cell counter widely used in laboratories. However, the effects of increased nucleated red blood cells (NRBCs) on the lymphocyte counts obtained using the UniCel DxH-800 have not been fully elucidated.
Objective: The study’s objective was to compare lymphocyte counts obtained using the DxH-800 and those obtained using flow cytometry in various ranges of NRBCs.
Methods: This cross-sectional study analyzed 25 healthy volunteers and 69 β-thalassemia/HbE patients. The numbers of lymphocytes were determined using a UniCel DxH-800 and a standard flow cytometer using counting beads.
Results: In healthy volunteers, regression analysis of the lymphocyte counts using the two approaches showed an r2 0.85 and a p < 0.0001, and a Bland-Altman plot showed mean bias of +264 cells/μL. In β-thalassemia/HbE patients, regression analysis of the lymphocyte counts obtained using an automated cell counter and a flow cytometer showed an r2 of 0.06, a p = 0.028, and a Bland-Altman plot showed the mean bias of +1,509 cells/μL. In addition, a high degree of discrepancy in the lymphocyte counts was observed in β-thalassemia/HbE patients who had NRBCs > 100,001 cells/μL.
Conclusions: The present study demonstrated that the UniCel DxH-800 performed well in enumerating lymphocytes in specimens that contained various numbers of NRBCs. However, a high number of NRBCs may interfere with lymphocyte counts obtained using the counter.
Key words: automated cell counter, nucleated red blood cell, lymphocyte, flow cytometry, β-thalassemia,