Performance of the Sysmex DI-60 for bronchoalveolar lavage cytology

Abstract Objectives Bronchoalveolar lavage (BAL) is a key diagnostic tool for evaluating pulmonary disorders . Manual microscopy is the reference standard for BAL cytology but is time-consuming. Although automated digital morphology platforms such as the Sysmex DI-60 Body Fluid (BF) application module have shown promise for other BFs, their performance in BAL analysis has not been systematically assessed. Therefore, we compared the performance of the Sysmex DI-60 BF application to manual microscopy for BAL differential white blood cell (WBC) counting and morphological assessment. Methods We evaluated 50 BAL samples processed according to standardized laboratory protocols for WBC counts and morphological features such as blood contamination, macrophage characteristics and epithelial cells. Cytospin slides stained with May-Grünwald-Giemsa were analyzed using the DI-60 BF application. WBC were first automatically classified (‘pre-classification’) into neutrophils, lymphocytes, monocytes/macrophages and eosinophils. Trained technicians reviewed and corrected classifications (‘post-classification’). Manual microscopy on parallel slides served as the reference method. Results DI-60 post-classification results showed moderate to strong correlations with manual counts across WBC subtypes (ρ=0.643–0.979). Bias of digital microscopy compared to manual microscopy was minimal for all WBC classes (range, −2.36 % to +2.56 %). Morphological assessments demonstrated 98–100 % agreement. Conclusions The BF module of the Sysmex DI-60 analyzer provided accurate BAL differential counts and morphological assessments with minimal bias compared to manual microscopy. Hence, the DI-60 may represent a useful alternative for BAL cytology within a routine laboratory workflow, provided optimized pre-analytical preparation and expert review for atypical cases are maintained.