Correlation between the cell population in the automated hematology analyzer high-fluorescence region and atypical...

During routine blood measurements using an automated hematology analyzer, two easily confused types of suspect flags related to lymphocytes often appear: atypical and immature lymphocytes. The aim of this study was to investigate the correlation of high fluorescence cell (HFC) parameter and lymphocyte flags determined from an automated hematology analyzer.

A total of 93 patients affected by various pathologic conditions (viral infection, immunological disease, oncological disease and tumor) were divided into an "atypical lymphocytes" group ("atypical" for short), an "immature lymphocytes/blasts" flag group (abnormal), a mixed-flag group that includes "atypical lymphocytes" (mixed), and a non-flag group (non-flag).

The numbers of HFCs in the atypical, abnormal, mixed, and non-flag groups were 1.8% (0.9%-5.5%), 0.7% (0.1%-5.0%), 2.3% (1.2%-5.0%), and 0.8% (0.7%-1.2%), respectively. The HFCs of "atypical" appeared as a separate cluster with clear boundaries. The HFCs of "abnormal" as an unclear boundaries, and it was difficult to accurately distinguish between the HFCs from the immature lymphocytes and the normal lymphocytes. The lower limit of HFC when the atypical lymphocyte flag appeared was 0.04 × 10⁹ /L. The number of HFCs was similar to atypical lymphocytes detected by microscopy and CD19⁺ CD20^- CD27⁺⁺ cells by flow cytometry at 78% and 76%, respectively. The number of HFCs detected in "atypical" and CD19⁺ CD20^- CD27⁺⁺ cells showed good consistency (r = .715), whereas the consistency was poorest for "abnormal" (r = .176).

It demonstrates that HFCs reflects atypical lymphocytes better than immature lymphocytes/blasts.