How Reproducible Is the Data from Sysmex DI-60 in Leukopenic Samples?

Area of Science:

• Hematology
• Clinical Pathology
• Medical Laboratory Science

Background:

• Digital morphology (DM) analyzers are integral to modern clinical practice.
• Evaluating DM analyzer performance on challenging samples, like leukopenic ones, is crucial.
• Previous studies have not focused specifically on the Sysmex DI-60's performance in leukopenia.

Purpose of the Study:

• To assess the analytical performance and precision of the Sysmex DI-60 system for white blood cell (WBC) differentials in leukopenic peripheral blood samples.
• To determine how WBC count affects the accuracy of DM analysis in leukopenic conditions.

Main Methods:

• Analysis of 40 peripheral blood smears categorized into normal, mild, moderate, and severe leukopenia groups (n=10 each).
• Evaluation of WBC preclassification precision using %coefficients of variation (%CVs).
• Comparison of Sysmex DI-60 differential counts against manual counts to determine mean differences and assess specificity/efficiency.

Main Results:

• Precision (%CVs) varied by sample and cell class, increasing with fewer cells per slide.
• High overall specificity (95.9-99.9%) and efficiency (90.0-99.4%) were observed for most cell classes, excluding plasma cells.
• Mean differences between DI-60 and manual counts increased significantly with the severity of leukopenia, reaching 47.74 in severe cases.

Conclusions:

• The Sysmex DI-60's performance in WBC differentials is significantly influenced by white blood cell count.
• DM analyzers require separate performance evaluations for leukopenic samples, even if overall performance appears acceptable.
• Findings highlight the need for careful validation of DM systems across diverse patient populations, particularly those with low WBC counts.