Evaluation of cell count and classification capabilities in body fluids using a fully automated Sysmex XN equipped with high-sensitive Analysis (hsA) mode and DI-60 hematology analyzer system

The XN series automated hematology analyzer has been equipped with a body fluid (BF) mode to count and differentiate leukocytes in BF samples including cerebrospinal fluid (CSF). However, its diagnostic accuracy is not reliable for CSF samples with low cell concentration at the border between normal and pathologic level. To overcome this limitation, a new flow cytometry-based technology, termed “high sensitive analysis (hsA) mode,” has been developed. In addition, the XN series analyzer has been equipped with the automated digital cell imaging analyzer DI-60 to classify cell morphology including normal leukocytes differential and abnormal malignant cells detection. Using various BF samples, we evaluated the performance of the XN-hsA mode and DI-60 compared to manual microscopic examination. The reproducibility of the XN-hsA mode showed good results in samples with low cell densities (coefficient of variation; % CV: 7.8% for 6 cells/μL). The linearity of the XN-hsA mode was established up to 938 cells/μL. The cell number obtained using the XN-hsA mode correlated highly with the corresponding microscopic examination. Good correlation was also observed between the DI-60 analyses and manual microscopic classification for all leukocyte types, except monocytes. In conclusion, the combined use of cell counting with the XN-hsA mode and automated morphological analyses using the DI-60 mode is potentially useful for the automated analysis of BF cells.XN系列全自动血液分析仪搭载了体液（Body Fluid, BF）模式，可对包括脑脊液（Cerebrospinal Fluid, CSF）在内的体液样本中的白细胞进行计数与分类。但对于细胞浓度处于正常与病理水平临界值的脑脊液样本，其诊断准确性并不可靠。为克服这一局限，一种基于流式细胞术（flow cytometry）的新技术——“高灵敏度分析（high sensitive analysis, hsA）模式”被开发出来。此外，XN系列分析仪还配备了自动化数字细胞成像分析仪DI-60，可对细胞形态进行分类，涵盖正常白细胞分类检测与异常恶性细胞识别。本研究采用多种体液样本，以手工显微镜检查为参照，评估了XN-hsA模式与DI-60的检测性能。XN-hsA模式在低细胞密度样本中表现出良好的重复性（变异系数（coefficient of variation, %CV）：6个细胞/微升时为7.8%）。其线性检测范围可达938个细胞/微升。XN-hsA模式所得的细胞计数结果与对应手工显微镜检查结果高度相关。除单核细胞外，DI-60的分析结果与各类白细胞的手工显微镜分类结果均呈现良好相关性。综上，将XN-hsA模式的细胞计数与DI-60模式的自动化形态学分析相结合，有望在体液细胞自动化分析中具备实用价值。