Cytometry Part B: Clinical Cytometry最新文献

van de Loosdrecht, A. A., Kern, W., Porwit, A., Valent, P., Kordasti, S., Cremers, E., Alhan, C., Duetz, C., Dunlop, A., Hobo, W., Preijers, F., Wagner-Ballon, O., Chapuis, N., Fontenay, M., Bettelheim, P., Eidenschink-Brodersen, L., Font, P., Johansson, U., Loken, M. R., … Ireland, R. (2023). Clinical application of flow cytometry in patients with unexplained cytopenia and suspected myelodysplastic syndrome: A report of the European LeukemiaNet International MDS-Flow Cytometry Working Group. Cytometry Part B: Clinical Cytometry, 104(1), 77–86. https://doi.org/10.1002/cyto.b.22044

In the originally published article, the Austrian Science Fund, Grant/Award Number: F4704 was incorrectly listed as a funder. This has been corrected in the online version of the article. We apologize for this error.

Diagnostic techniques within hematology are becoming more sensitive and measurable residual disease (MRD) is gaining importance as a result—for both diagnosticians and patients. MRD measurement is increasingly used as a study endpoint in clinical trials and also in routine diagnostics—and as a strong predictor of treatment outcome. Currently, more sensitive and specific methods of measurement are in development. Besides molecular assays, flow cytometry is one of the most frequently used methods for MRD assessment due to its shorter turnaround time, its cost-effectiveness, and broader applicability.

In this issue, several researchers have delved into various aspects of flow cytometry techniques being used for MRD detection within hematological malignancies. Gao et al. introduced a single tube flow cytometry assay with high sensitivity for monitoring MRD in B-lymphoblastic leukemia/lymphoma (B-ALL), independent of specific surface antigen expression like CD19 and CD22. As the authors point out, the development of such assays has become relevant due to the emergence of targeted anti-CD19 and anti-CD22 therapies (Gao, Chen, et al., 2023; Gao, Liu, et al., 2023). Targeted immunotherapy demonstrated encouraging results in recent years but induces significant changes in the phenotype of leukemic blasts concurrently. Therefore, alternative gating strategies have gained importance and potential CD19 substitutes have been proposed (Chen et al., 2023; Mikhailova et al., 2022).

The development of alternative gating strategies is also relevant independently of targeted therapies, as shown by the authors of the next article. In a rare case study, Ramalingam et al. reported a patient with CD19-negative diffuse large B-cell lymphoma (DLBCL). Since CD19 is currently the primary gating marker for B cell neoplasms, its absence may lead to erroneous results and potentially affect therapeutic strategies, so the authors (Ramalingam et al., 2022). Challenges for flow cytometry approaches have been studied before (Gao, Chen, et al., 2023; Gao, Liu, et al., 2023; Huang et al., 2023; Martig & Fromm, 2022).

In MRD detection, the avoidance of false positives is crucial as shown by Zhou et al. The authors discussed the pitfalls in MRD detection in B-ALL following targeted immunotherapy, describing the presence of two CD22-positive non-neoplastic cell populations. One progenitor population of uncertain lineage and one mature B-cell population were both immunophenotypic mimics of B-ALL. Zhou et al. concluded that an understanding of these normal cell populations is essential to avoid misinterpretation in MRD assessments and CD19-independent gating strategies, including CD22 and CD24, are key (Zhou et al., 2022). Optimizing MRD measurement is at the forefront of numerous studies and alternative antigens (besides CD22 and CD24

The assessment of measurable residual disease (MRD) has emerged as a powerful prognostic tool for both pediatric and adult acute lymphoblastic leukemia (ALL). This retrospective study aimed to evaluate the prognostic relevance of the end of induction MRD in B-cell acute lymphoblastic leukemia (B ALL) patients. The study included 481 patients who underwent treatment for B ALL between August 2012 and March 2019 and had their MRD at the end of induction assessed by flow cytometry. Baseline demographic characteristics were collected from the patient's clinical records. Event free survival (EFS) and relapse free survival (RFS) were calculated using Kaplan–Meier analysis and survival estimates were compared using the log-rank test. End of induction MRD and baseline karyotype were the strongest predictors of EFS and RFS on multivariate analysis. The EFS was inversely related to the MRD value and the outcomes were similar in patients without morphological remission at the end of induction and patients in remission with MRD ≥1.0%. Even within the subgroups of ALL based on age, karyotype, BCR::ABL1 translocation and the treatment protocol, end of induction MRD positive patients had poor outcomes compared to patients who were MRD negative. The study outcome would help draft end of induction MRD-based treatment guidelines for the management of B ALL patients.

Background: Mature B-cell neoplasms are challenging to diagnose due to their heterogeneity and overlapping clinical and biological features. In this study, we present a new workflow strategy that leverages a large amount of flow cytometry data and an artificial intelligence approach to classify these neoplasms.

Methods: By combining mathematical tools, such as classification algorithms and regression tree (CART) models, with biological expertise, we have developed a decision tree that accurately identifies mature B-cell neoplasms. This includes chronic lymphocytic leukemia (CLL), for which cytometry has been extensively used, as well as other non-CLL subtypes.

Results: The decision tree is easy to use and proposes a diagnosis and classification of mature B-cell neoplasms to the users. It can identify the majority of CLL cases using just three markers: CD5, CD43, and CD200.

Conclusion: This approach has the potential to improve the accuracy and efficiency of mature B-cell neoplasm diagnosis.

Immune monitoring of patients on a single-cell level is becoming increasingly important in various diseases. Due to the often very limited availability of human specimens and our increased understanding of the immune systems there is an increasing demand to analyze as many markers as possible simultaneously in one panel. Full spectrum flow cytometry is emerging as a powerful tool for immune monitoring since 5-laser instruments enable characterization of 40 parameters or more in a single sample. Nevertheless, even if only machines with fewer lasers are available, development of novel fluorophore families enables increasing panel sizes. Here, we demonstrate that careful panel design enables the use of 31-color panels on a 3-laser Cytek® Aurora cytometer for analyzing human peripheral blood leukocytes, without the need for custom configuration and using only commercially available fluorochromes. The panel presented here should serve as an example of a 31-fluorochrome combination that can be resolved on a 3-laser full spectrum cytometer and that can be adapted to comprise other (and possibly more) markers of interest depending on the research focus.