Cytometry Part B: Clinical Cytometry最新文献

This new issue of Cytometry B (Clinical Cytometry) consists of five main manuscripts which contain original research in the field of clinical cytometry. A manuscript describing a simple (new) method for preservation of urinary cells for subsequent flow cytometric analyses (Freund et al., 2023) opens this issue of the journal. It is followed by three papers related to the application of flow cytometry in the field of acute leukemias. In the first two manuscripts distinct assays for measurable residual disease (MRD) monitoring in acute myeloblastic leukemia (AML) (Tettero et al., 2023) and B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) (Arunachalam et al., 2023) are (technically and clinically) validated, whereas the third one consists of a comparison and validation of four immunophenotypic scoring systems for the diagnosis of early-T precursor (ETP) acute lymphoblastic leukemia (ALL) (Basavaraju et al., 2023). The fifth article in this issue of Cytometry B revisits the application of flow cytometry for HLA-B27 typing through the comparison of 3 CE-IVD certified methods (Waeckel et al., 2023). Three letters to the editor complete the contents of the November issue of Cytometry B, in which different aspects of three clinically relevant flow cytometric assays for sepsis (Haem-Rahimi et al., 2023), drug-induced hypersensitivity (Ebo et al., 2023) and diagnostic screening of acute leukemias (Axler et al., 2023), are briefly addressed. In this section, I will summarize the contents and highlight the most relevant contributions of the above papers in four separate blocks related to the fields of (i) the flow cytometric analysis of samples with low cell viability, (ii) the flow cytometric diagnosis and monitoring of acute leukemias, (iii) HLA-B27 typing and (iv) the feasibility to measure HLADR expression levels on stabilized blood monocytes and blood circulating drug-specific T cells in the diagnostic work-up of sepsis and drug-hypersensitivity, respectively.

Flow cytometry assays used in diagnostic laboratories have mostly focused on blood samples and to a less extent also, in bone marrow and other tissue and body fluid specimens. Despite the high frequency of kidney and urinary tract diseases in the general population, and the frequent need for invasive diagnostic procedures (e.g., kidney biopsy), urine has been one of the less explored and used specimens among the distinct types of body fluids evaluated in (clinical) flow cytometry. Of note, urine samples are frequently obtained for conventional biochemistry assays, including analysis of proteinuria, and for the evaluation of the urine sediment by conventional, for example, cytomorphology. In contrast, flow cytometric analysis of urinary cells (e.g., immune cells, podocytes or epithelial cells) is rarely used in routine diagnostics, despite it has proven to provide valuable infor

The article in this issue of Cytometry B on “Standardization of Flow Cytometric Detection of Antigen Expression” by the NCI clinical cytometry group formerly headed by Maryalice Stetler-Stevenson and the NIST group headed by Lili Wang is deserving of not only an accompanying editorial, but special attention by all those readers intending to work in clinical cytometry for the coming decade, as it describes an important future component of diagnostic cellular analysis (Tain et al., 2023). Specifically, the ability to measure the antigen (or probe target) expression on well-characterized cell populations will be a vital component of not only monitoring of patients with malignancy, as discussed in the article by Tian et al. herein (Tain et al., 2023) but also monitoring of a variety of immune responses or therapeutically altered defined cell populations. A few predictions as to what true antigen quantitation will provide: (1) treatment of sickle cell disease will be adjusted through a standardized measurement of the level of hemoglobin F in F cells (Hgb F containing RBCs) in order to retard the sickling process (De Souza et al., 2023); (2) patients with severe infection, cytokine storms and certainly sepsis will be monitored for a combination of activation markers (CD64, CD169, HLA-Dr and others) on neutrophils, monocytes and other cell types for informative and actionable changes regarding the immune status (Bourgoin et al., 2020; Davis et al., 2006; Davis & Bigelow, 2005; Ortillon et al., 2021; Schiff et al., 1997); (3) Rapid assays for the genetic expression of newly induced targets (CAR-T cells, adenovirus insertion of other targeting receptors, etc.).

The paper also compares two commonly advocated quantitation methods, PE labeled beads to derive average or median antibody binding capacity (ABC) per cell (Davis et al., 1998) vs. single point transformation or ratiometric comparison of the targeted cell population to the CD4 expression on helper T cells using an assumed 40,000 CD4 mAb binding sites per cell (Degheidy et al., 2016; Wang et al., 2016). Other technical variables the paper convincingly observed is that purified 1:1 PE:antibody preparations give better precision than regular off-the-shelf PE-labeled antibody lots, even if the measured F/P ratio of the off the shelf preparation is close to 1.00. Not surprisingly the study provides quantitative evidence that clone selection does matter and different clones with the same reported target antigen specificity can give variable results, up to nearly a two-fold difference in ABC units and this difference was in no way correctable using the reported F/P ratio of the antibody lot. While the use of 1:1 PE:antibody preparation along with spectrally matched beads for ABC quantitation gave acceptable imprecision with a CV between four instruments