Accuracy of lymphocyte counts from UniCel DxH 800 in β-thalassemia/HbE patients having various numbers of nucleated red blood cells

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 lym-phocyte counts obtained using the counter.