Automated identification of leukocyte subsets improves standardization of database-guided expert-supervised diagnostic orientation in acute leukemia: a EuroFlow study

Abstract

Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide toward the relevant classification panel and final diagnosis. In this study, we designed and validated an algorithm for automated (database-supported) gating and identification (AGI tool) of cell subsets within samples stained with ALOT. A reference database of normal peripheral blood (PB, n = 41) and bone marrow (BM; n = 45) samples analyzed with the ALOT was constructed, and served as a reference for the AGI tool to automatically identify normal cells. Populations not unequivocally identified as normal cells were labeled as checks and were classified by an expert. Additional normal BM (n = 25) and PB (n = 43) and leukemic samples (n = 109), analyzed in parallel by experts and the AGI tool, were used to evaluate the AGI tool. Analysis of normal PB and BM samples showed low percentages of checks (<3% in PB, <10% in BM), with variations between different laboratories. Manual analysis and AGI analysis of normal and leukemic samples showed high levels of correlation between cell numbers (r2 > 0.95 for all cell types in PB and r2 > 0.75 in BM) and resulted in highly concordant classification of leukemic cells by our previously published automated database-guided expert-supervised orientation tool for immunophenotypic diagnosis and classification of acute leukemia (Compass tool). Similar data were obtained using alternative, commercially available tubes, confirming the robustness of the developed tools. The AGI tool represents an innovative step in minimizing human intervention and requirements in expertise, toward a “sample-in and result-out” approach which may result in more objective and reproducible data analysis and diagnostics. The AGI tool may improve quality of immunophenotyping in individual laboratories, since high percentages of checks in normal samples are an alert on the quality of the internal procedures.

Immature acute leukaemias: lessons from the haematopoietic roadmap

“…For example, the EuroFlow consortium has developed antibody panels [24] and standardized protocols [25] for diagnosis of haematological malignancies. More recently, these efforts have extended to development of automated gating strategies [26,27] that would further improve diagnostic reproducibility through more reliable and robust identification and characterisation of…”

Issue Highlights—May 2022

“…showing that machine-learning algorithms for annotating flow cytometry gating definitions of standardized cell types and functions can be used to integrate data provided by different assays in multicenter studies. This supervised approach is different from the probability state modeling (Bagwell et al, 2020), from automated gating and identification tools (Lhermitte et al, 2021;Linskens et al, 2020) and from other computational tools aimed at the management of high-content cytometric data (Cheung et al, 2021). Here the definitions of cell…”

Finding a treasure in the rear‐view mirror?

“…changing the whole field even more. Published data on automated analysis of such data collections showed ability to reduce analysis time and subjectivity [8–11].…”

“…changing the whole field even more. Published data on automated analysis of such data collections showed ability to reduce analysis time and subjectivity [8][9][10][11]. were not looking for, on the other hand automated tools treat the dataset as whole using only information explicitly provided for the task at hand.…”

“…This is certainly a finding worth confirming independently. Nevertheless, we should not forget that scatters are more difficult to standardize than fluorescent parameters [13] and are influenced by adherence to standard operating procedure [10]. Type of erythrocyte lysis influences both: forward and side scatter parameters and abundance of nucleated erythroid cells.…”