Imaging flow cytometric detection of del(17p) in bone marrow and circulating plasma cells in multiple myeloma.

BACKGROUND: Detection of del(17p) in myeloma is generally performed by fluorescence in situ hybridization (FISH) on a slide with analysis of up to 200 nuclei. The small cell sample analyzed makes this a low precision test. We report the utility of an automated FISH method, called "immuno-flowFISH", to detect plasma cells with adverse prognostic risk del(17p) in bone marrow and blood samples of patients with myeloma. METHODS: Bone marrow (n = 31) and blood (n = 19) samples from 35 patients with myeloma were analyzed using immuno-flowFISH. Plasma cells were identified by CD38/CD138-immunophenotypic gating and assessed for the 17p locus and centromere of chromosome 17. Cells were acquired on an AMNIS ImageStreamX MkII imaging flow cytometer using INSPIRE software. RESULTS: Chromosome 17 abnormalities were identified in CD38/CD138-positive cells in bone marrow (6/31) and blood (4/19) samples when the percent plasma cell burden ranged from 0.03% to 100% of cells. Abnormalities could be identified in 14.5%-100% of plasma cells. CONCLUSIONS: The "immuno-flowFISH" imaging flow cytometric method could detect del(17p) in plasma cells in both bone marrow and blood samples of myeloma patients. This method was also able to detect gains and losses of chromosome 17, which are also of prognostic significance. The lowest levels of 0.009% (bone marrow) and 0.001% (blood) for chromosome 17 abnormalities was below the detection limit of current FISH method. This method offers potential as a new means of identifying these prognostically important chromosomal defects, even when only rare cells are present and for serial disease monitoring.

Chimeric antigen receptor T-cells: Properties, production, and quality control.

Chimeric antigen receptor (CAR) T-cell therapy is a novel adoptive T-cell immunotherapy for haematological malignancies. First introduced into clinical practice in 2017, CAR T-cell therapy is now finding its place in the management of lymphoid malignancies, primarily of B-cell lineage, including lymphoblastic leukaemia, non-Hodgkin lymphoma and plasma cell myeloma, with remarkable therapeutic outcomes. CAR T-cells are a customised therapeutic product for each patient. Manufacture commences with collection of autologous T-cells, which are then genetically engineered ex vivo to express transmembrane CARs. These chimeric proteins consist of an antibody-like extracellular antigen-binding domain, to recognise specific antigens on the surface of tumour cells (e.g. CD19), linked to the intracellular co-stimulatory signalling domains of a T-cell receptor (e.g. CD137). The latter is required for in vivo CAR T-cell proliferation, survival, and durable efficacy. Following reinfusion, CAR T-cells harness the cytotoxic capacity of a patient's immune system. They overcome major mechanisms of tumour immuno-evasion and have potential to generate robust cytotoxic anti-tumour responses. This review discusses the background to CAR T-cell therapies, including their molecular design, mechanisms of action, methods of production, clinical applications and established and emerging technologies for CAR T-cell evaluation. It highlights the need for standardisation, quality control and monitoring of CAR T-cell therapies, to ensure their safety and efficacy in clinical management.

"Immuno-FlowFISH": Applications for Chronic Lymphocytic Leukemia.

Imaging flow cytometry has the capacity to bridge the gap that currently exists between the diagnostic tests that detect important phenotypic and genetic changes in the clinical assessment of leukemia and other hematological malignancies or blood-based disorders. We have developed an "Immuno-flowFISH" method that leverages the quantitative and multi-parametric power of imaging flow cytometry to push the limits of single-cell analysis. Immuno-flowFISH has been fully optimized to detect clinically significant numerical and structural chromosomal abnormalities (i.e., trisomy 12 and del(17p)) within clonal CD19/CD5+ CD3- Chronic Lymphocytic Leukemia (CLL) cells in a single test. This integrated methodology has greater accuracy and precision than standard fluorescence in situ hybridization (FISH). We have detailed this immuno-flowFISH application with a carefully catalogued workflow, technical instructions, and a repertoire of quality control considerations to supplement the analysis of CLL. This next-generation imaging flow cytometry protocol may provide unique advancements and opportunities in the holistic cellular assessment of disease for both research and clinical laboratory settings.

Multi-probe FISH Analysis of Immunophenotyped Chronic Lymphocytic Leukemia by Imaging Flow Cytometry.

Imaging flow cytometry is an automated method that enables cells and fluorescent signals to be visualized and quantified. Here, we describe a new imaging flow cytometry method whereby fluorescence in situ hybridization (FISH) is integrated with cell phenotyping. The method, called "immuno-flowFISH," provides an exciting new dimension for the analysis of genomic changes in cytological samples (e.g., blood, bone marrow). Cells are analyzed in suspension without any requirement for prior cell isolation or separation. Multiple antibodies and FISH probes, each with a unique fluorophore, can be added and many thousands of cells analyzed. Specific cell populations are identified by their antigenic profile and then analyzed for the presence of chromosomal defects. Immuno-flowFISH was applied to the assessment of chronic lymphocytic leukemia (CLL), a mature B-cell neoplasm where chromosomal abnormalities predict prognosis and treatment requirements. This integrated immunophenotyping and multi-probe FISH strategy could detect both structural and numerical chromosomal changes involving chromosomes 12 and 17 in CLL cells. Given that many thousands of cells were analyzed and the leukemic cells were positively identified by their immunophenotype, this multi-probe method adds precision to the cytogenomic analysis of CLL. © 2021 Wiley Periodicals LLC.

"Immuno-flowFISH" for the Assessment of Cytogenetic Abnormalities in Chronic Lymphocytic Leukemia.

Imaging flow cytometry is emerging as a diagnostic tool for the assessment of leukemia. It has the functionality of standard flow cytometry and generates high-resolution digital images of each cell with quantifiable numerical data. We demonstrate the use of an automated high-throughput method for performing fluorescence in situ hybridization (FISH) on immunophenotyped whole cells in suspension and analyzed by imaging flow cytometry, a technique called "Immuno-flowFISH". The aim of this study was to demonstrate the application of immuno-flowFISH for the detection of chromosomal abnormalities in CLL, specifically trisomy 12 and del(17p). Mononuclear cells were isolated and immunophenotyped with fluorescently conjugated CD3, CD5, and CD19 monoclonal antibodies. Following fixation, cells were permeabilized, dsDNA denatured and hybridized with chromosome 12 or 17 enumeration (CEP 12 and CEP17) and 17p12 locus-specific FISH probes. Cells were analyzed on the Amnis ImageStream®X Mark II to assess the number and percent FISH-positive CLL cells and the ratio of FISH spot counts for CD5/CD19-positive CLL cells to CD3/CD5-positive T cells (FISH "mean spot ratio"). Deletion of 17p was detected in about 8% of cases to date, with del(17p) ranged from 3.5-22.8% and the FISH "mean spot ratio" 0.86-0.96. Immuno-flowFISH also detected a minimal residual disease case with +12 with a limit of detection of 0.13% and a rare case that presented with atypical phenotype and cytogenetics. Immuno-flowFISH could detect del(17p) in phenotypically identified CD5/CD19-positive B-cells. The 100-fold increase in analyzed cells, as well as the addition of cell phenotype increased the sensitivity and specificity over current clinical FISH testing. Furthermore, immuno-flowFISH analysis demonstrated specific utility in unique clinical scenarios such as residual disease and atypical biology cases which may be of significant benefit with regards to prognostication and MRD analysis. The method will assist in therapeutic decision making and disease monitoring for many hematological malignancies. © 2019 International Society for Advancement of Cytometry.