Background: Due to the high false-positive rate of the high-fluorescence body fluid (HF-BF) cell parameter of the hematology analyzer in BF mode, a novel algorithm based on the Mindray BC-6800 Plus hematology analyzer (BC-6800Plus), with higher diagnostic accuracy compared to that of the traditional HF-BF algorithm, was used to screen for malignant tumor cells in clinical BF samples. In this study, the body fluid mode of BC-6800Plus was applied to investigate the ability of its available parameters and characteristic regional particles in tumor cells screening.
Methods: A total of 220 BF samples (including pleural effusion and ascites) were randomly classified into a training cohort (154 samples) and a validation cohort (66 samples), and detected on the BC-6800Plus in BF mode. Based on the scatter plot analysis of the instrument, a novel gating algorithm, malignant cell algorithm-body fluid (MA-BF), was designed to detect the aggregated cells expressing highest fluorescence (FL) signals and side-scatter (SS) signals than other cells. BF collection and analyses were performed in compliance with the CLSI H56-A guideline. tumor cell-positive samples were defined as greater than or equal to confirIIIb (Papanicolaou class system) by the pathological examination. The diagnostic accuracy of HF-BF and MA-BF were determined by the receiver operating characteristic (ROC) curve analysis.
Results: When the cutoff values of the absolute count (HF-BF#) and relative count (HF-BF%) were set as 0.022×109/L and 3.0%, respectively, the area under curve (AUC), sensitivity, and specificity were 0.76, 0.85 and 0.55 for HF-BF#, and were 0.70, 0.85, and 0.49 for HF-BF%, respectively. The new parameters, the absolute tumor cell count (MA-BF#) and relative count (MA-BF%), were established in the training cohort using the novel algorithm. We confirmed the cutoff values of MA-HF# and MA-HF% in BF were set as 0.006×109/L and 0.2% in the training cohort, respectively. In the validation cohort, the AUC, sensitivity, and specificity were 0.89, 0.93, and 0.78 for MA-BF#, and were 0.89, 0.87 and 0.75 for MA-BF%, respectively.
Conclusions: The MA-BF parameters of the novel algorithm output had better diagnostic accuracy for BF tumor cells than the traditional HF-BF parameters.
Keywords: Hematology analyzer; body fluid (BF); high-fluorescent; malignant cells; novel algorithm.
2022 Annals of Translational Medicine. All rights reserved.