Novel flowcytometry-based approach of malignant cell detection in body fluids using an automated hematology analyzer

Abstract

Morphological microscopic examinations of nucleated cells in body fluid (BF) samples are performed to screen malignancy. However, the morphological differentiation is time-consuming and labor-intensive. This study aimed to develop a new flowcytometry-based gating analysis mode “XN-BF gating algorithm” to detect malignant cells using an automated hematology analyzer, Sysmex XN-1000. XN-BF mode was equipped with WDF white blood cell (WBC) differential channel. We added two algorithms to the WDF channel: Rule 1 detects larger and clumped cell signals compared to the leukocytes, targeting the clustered malignant cells; Rule 2 detects middle sized mononuclear cells containing less granules than neutrophils with similar fluorescence signal to monocytes, targeting hematological malignant cells and solid tumor cells. BF samples that meet, at least, one rule were detected as malignant. To evaluate this novel gating algorithm, 92 various BF samples were collected. Manual microscopic differentiation with the May-Grunwald Giemsa stain and WBC count with hemocytometer were also performed. The performance of these three methods were evaluated by comparing with the cytological diagnosis. The XN-BF gating algorithm achieved sensitivity of 63.0% and specificity of 87.8% with 68.0% for positive predictive value and 85.1% for negative predictive value in detecting malignant-cell positive samples. Manual microscopic WBC differentiation and WBC count demonstrated 70.4% and 66.7% of sensitivities, and 96.9% and 92.3% of specificities, respectively. The XN-BF gating algorithm can be a feasible tool in hematology laboratories for prompt screening of malignant cells in various BF samples.

Lack of harmonization in high fluorescent cell automated counts with body fluids mode in ascitic, pleural, synovial, and cerebrospinal fluids

“…The cytometric assessment of BFs is typically performed in modern hemocytometers using a dedicated channel, conventionally known as BF mode (BF‐mode) . The presence of certain types of cells, usually absent in peripheral blood but occasionally identifiable in BFs (eg, macrophages, mesothelial cells, not hematological neoplastic cells, and synoviocytes), is perhaps the most important limitation of automated cell counting . All these cells share some common morphological features, including medium‐large size, biological activity (eg, replication or activation) and medium or high cytoplasmic complexity.…”

“…For both XN‐BF and BC‐BF modes, the number of cells classified as HF‐BF is significantly correlated with the presence of mesothelial and/or various neoplastic cells . According to the origin of the BF, the presence of a variable number of cells classified as HF‐BF can then suggest microscopic revision of the sample …”

“…[1][2][3] The presence of certain types of cells, usually absent in peripheral blood but occasionally identifiable in BFs (eg, macrophages, mesothelial cells, not hematological neoplastic cells, and synoviocytes), is perhaps the most important limitation of automated cell counting. [1][2][3][19][20][21][22][23] All these cells share some common morphological features, including medium-large size, biological activity (eg, replication or activation) and medium or high cytoplasmic complexity. Using May-Grunwald staining, the cytoplasm of these cells is variably basophilic, whilst the ratio between nucleus and cytoplasm varies according to the cell type.…”

“…4,[6][7][8][9][10]13,[15][16][17][18][20][21][22] According to the origin of the BF, the presence of a variable number of cells classified as HF-BF can then suggest microscopic revision of the sample. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The identification of an accurate cut-off for HF-BF and other parameters, both qualitative and quantitative, is very useful in routine practice for increasing the appropriateness of microscopic revision and for reducing the risk of generating false negative results. Along with cell count and classification (thus including HF-BF count in absolute or relative value), both Sysmex and Mindray analyzers generate qualitative information that can be captured from scattergrams or dot plots of the differential cell count (ie, WDF-scattergram for XN-BF [XN-BF-WDF] and DIFF-scattergram for BC-BF [BC-BF-DIFF], respectively), but it is still unclear whether or not these parameters truly reflect identical cellular elements.…”

The diagnostic ability of high‐fluorescent cells combined with carcinoembryonic antigen for malignant pleural effusion

“…Traditionally, exfoliative cytology is performed by microscopic examination, which is time‐consuming, has low sensitivity, and may lead to a delay in the early diagnosis of patients. Recently, hematology analyzers for assessing BF have received much attention because they can improve laboratory efficiency and cost‐effectiveness, A few studies have been dedicated to assessing the performance of automated hematology analyzers and comparing the correlation between the automated method and manual microscopic method, These studies showed that the automated methods had good agreement with the manual microscopic method and had better precision. The body fluid mode (BF mode) introduced by the Sysmex XN9000 can automatically count the red blood cells, white blood cells, mononuclear cells (MN), and polymorphonuclear cells (PMN) in serosal cavity effusions, including pleural effusion, cerebrospinal fluid, and articular fluid.…”