Performance Evaluation of Body Fluid Cellular Analysis Using the Beckman Coulter UniCel DxH 800, Sysmex XN-350, and UF-5000 Automated Cellular Analyzers

Abstract

Background: Automated cellular analyzers are expected to improve the analytical performance in body fluid (BF) analysis. We evaluated the analytical performance of three automated cellular analyzers and established optimum reflex analysis guidelines.

Methods: A total of 542 BF samples (88 cerebrospinal fluid [CSF] samples and 454 non-CSF samples) were examined using manual counting and three automated cellular analyzers: UniCel DxH 800 (Beckman Coulter), XN-350 (Sysmex), and UF-5000 (Sysmex). Additionally, 2,779 BF analysis results were retrospectively reviewed. For malignant cell analysis, the receiver operating characteristic (ROC) curve was used, and the detection of high fluorescence-BF cells (HF-BFs) using the XN-350 analyzer was compared with cytology results.

Results: All three analyzers showed good agreement for total nucleated cell (TNC) and red blood cell (RBC) counts, except for the RBC count in CSF samples using the UniCel DxH 800. However, variable degrees of differences were observed during differential cell counting. For malignant cell analysis, the area under the curve was 0.63 for the XN-350 analyzer and 0.76 for manual counting. We established our own reflex analysis guidelines as follows: HF-BFs <0.7/100 white blood cells (WBCs) is the criterion for quick scans with 100× magnification microscopic examination as a rule-out cut-off, while HF-BFs >83.4/100 WBCs or eosinophils >3.8% are the criteria for mandatory double check confirmation with 1,000× magnification examination.

Conclusions: The three automated analyzers showed good analytical performances. Application of reflex analysis guidelines is recommended for eosinophils and HF-BFs, and manual confirmation is warranted.

Keywords: Analytical performance; Automated cellular analyzer; Body fluid; Differential cell counting; UF-5000; UniCel DxH 800; XN-350.

Fig. 1. ROC curve analysis of HF-BFs obtained using the Sysmex XN-350 and other cells obtained by manual counting compared with positive results (positive for malignancy and atypical cells) determined by cytology. Lining cells and monocytes/histiocytes were classified together as MNs. Macrophages, lining cells, such as mesothelial cells, atypical cells, and malignant cells were counted as “other cells.”

Abbreviations: HF-BFs, high fluorescence-body fluid cells; TPF, true positive fraction; FPF, false positive fraction; AUC, area under the curve; CI, confidence interval; MNs, mononuclear cells.