Leukemia-Specific Scatterplots and Blast Detection Using the XN-1000 Hematology Analyzer

Background: The complete blood cell count with differential is particularly important in the diagnosis and monitoring of hematologic malignancies. The visual examination of blood films is a labor-intensive process and the results are affected by the experience of the hematopathologist. Automated hematology analyzers are used to count and identify blood cells in most laboratories. Methods: EDTA-treated blood samples were collected from 318 patients diagnosed with acute and chronic leukemia and 150 normal controls. Twelve XN-1000 white blood cell scatterplots of each case were displayed and characteristic differences from the normal scatterplot were evaluated. We describe the specific scatterplots of normal controls and patients in each disease. Results: Each type of leukemia shows characteristic scatterplots, some of which report blast counts. The WPC plot revealed an oblique downward trend in the low-FSC blast population typically, whereas the leukemic cells in acute promyelocytic leukemia showed the characteristic signal in the oblique upward direction on the SSC-FSC plot. The high:low FSC lymphocyte ratio was decreased in chronic lymphocytic leukemia (CLL), whereas B-cell prolymphocytic leukemia (B-PLL) showed increased high:low FSC lymphocyte ratio. Both B-PLL and T-PLL showed the same scatterplot. Conclusions: XN scatterplots represent morphology of the blood cells. Each type of leukemia shows a characteristic scatterplot including WPC plot. XN reveals blast counts and leukemia type. (Clin. Lab. 2022;68:xx-xx. DOI: 10.7754/Clin.Lab.2021.210926)