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Multiparameter Flow Cytometry (multiparameter + flow_cytometry)
Selected AbstractsA chromatic explosion: the development and future of multiparameter flow cytometryIMMUNOLOGY, Issue 4 2008Pratip K. Chattopadhyay Summary Multiparameter flow cytometry has matured tremendously since the 1990s, giving rise to a technology that allows us to study the immune system in unprecedented detail. In this article, we review the development of hardware, reagents, and data analysis tools for multiparameter flow cytometry and discuss future advances in the field. Finally, we highlight new applications that use this technology to reveal previously unappreciated aspects of cell biology and immunity. [source] Comprehensive flow cytometry phenotype in acute leukemia at diagnosis and at relapseAPMIS, Issue 5 2010XIN LI Li X, Du W, Liu W, Li X, Li H, Huang S-A. Comprehensive flow cytometry phenotype in acute leukemia at diagnostic and at relapse. APMIS 2010; 118: 353,59. Multiparameter flow cytometry (MFC) plays a vital role in the detection of minimal residual disease (MRD) and diagnosis of relapse in acute leukemia. However, application of a limited panel of antibodies in MFC leads to high rates of false-negative and false-positive results. Thirteen patients with acute lymphoblastic leukemia (ALL) and 12 patients with acute myeloid leukemia (AML) were immunophenotyped by MFC at diagnosis and at relapse using a comprehensive panel of monoclonal antibodies (McAbs) to 27 antigens and CD45/SSC gating. In 23 of 25 patients (92.3%), changes in at least one of progenitor-associated, myeloid and lymphoid antigens between diagnosis and relapse were observed. Antigen changes were observed in 92 of 239 antigens (38.5%) expressed in 25 patients, in 49 of 117 antigens (41.9%) expressed in 13 ALL patients, and in 43 of 122 antigens (35.2%) expressed in 12 AML patients. Phenotypic changes were characterized by the expression of cross-lineage antigens. The intralineage change was observed in the majority of patients. However, myeloid lineage shift was identified by MFC in two patients with T-ALL. Multiple panels of three or more McAbs are likely to be required in the monitoring of MRD and diagnosis of relapse in acute leukemia by MFC. [source] Utility of flow cytometry immunophenotyping in multiple myeloma and other clonal plasma cell-related disorders,CYTOMETRY, Issue 4 2010Bruno Paiva Abstract In recent years, multiparameter flow cytometry (MFC) immunophenotyping has become mandatory in the clinical management of hematological malignancies, both for diagnostic and monitoring purposes. Multiple myeloma (MM) and other clonal plasma cell-related (PC) disorders should be no exception to this paradigm, but incorporation of immunophenotypic studies in the management of patients with PC disorders is still far from being routinely established in many diagnostic flow cytometry laboratories. For clonal PC disorders, MFC is of clear and established clinical relevance in: (1) the differential diagnosis between MM and other PC-related disorders; (2) the identification of high-risk MGUS and smoldering MM; (3) minimal residual disease investigation after therapy; additionally it may also be useful for (4) the definition of prognosis-associated antigenic profiles; and (5) the identification of new therapeutic targets. In this article, we review the clinical value of MFC in the study of PC disorders, with specific emphasis in those areas where consensus exists on the need to incorporate MFC into routine evaluation of MM and other clonal PC-related disorders. © 2010 Clinical Cytometry Society [source] Four- and five-color flow cytometry analysis of leukocyte differentiation pathways in normal bone marrow: A reference document based on a systematic approach by the GTLLF and GEIL,,CYTOMETRY, Issue 1 2010Christine Arnoulet Abstract Background: The development of multiparameter flow cytometry (FCM) and increasingly sophisticated analysis software has considerably improved the exploration of hematological disorders. These tools have been widely applied in leukaemias, lymphomas, and myelodysplasias, yet with very heterogeneous approaches. Consequently, there is no extensive reference document reporting on the characteristics of normal human bone marrow (BM) in multiparameter FCM. Here, we report a reference analysis procedure using relevant antibody combinations in normal human BM. Methods: A first panel of 23 antibodies, constructed after literature review, was tested in four-color combinations (including CD45 in each) on 30 samples of BM. After evaluation of the data, a second set of 22 antibodies was further applied to another 35 BM samples. All list-modes from the 65 bone marrow samples were reviewed collectively. A systematised protocol for data analysis was established including biparametric representations and color codes for the three major lineages and undifferentiated cells. Results: This strategy has allowed to obtain a reference atlas of relevant patterns of differentiation antigens expression in normal human BM that is available within the European LeukemiaNet. This manuscript describes how this atlas was constructed. Conclusions: Both the strategy and atlas could prove very useful as a reference of normality, for the determination of leukemia-associated immunophenotypic patterns, analysis of myelodysplasia and, ultimately, investigation of minimal residual disease in the BM. © 2009 Clinical Cytometry Society [source] Diagnosing PNH with FLAER and multiparameter flow cytometryCYTOMETRY, Issue 3 2007D. Robert Sutherland Abstract Background: PNH is an acquired hematopoietic stem cell disorder leading to a partial or absolute deficiency of all glycophosphatidyl-inositol (GPI)-linked proteins. The classical approach to diagnosis of PNH by cytometry involves the loss of at least two GPI-linked antigens on RBCs and neutrophils. While flow assays are more sensitive and specific than complement-mediated lysis or the Hams test, they suffer from several drawbacks. Bacterial aerolysin binds to the GPI moiety of cell surface GPI-linked molecules and causes lysis of normal but not GPI-deficient PNH cells. FLAER is an Alexa488-labeled inactive variant of aerolysin that does not cause lysis of cells. Our goals were to develop a FLAER-based assay to diagnose and monitor patients with PNH and to improve detection of minor populations of PNH clones in other hematologic disorders. Methods: In a single tube assay, we combined FLAER with CD45, CD33, and CD14 allowing the simultaneous analysis of FLAER and the GPI-linked CD14 structure on neutrophil and monocyte lineages. Results: Comparison to standard CD55 and CD59 analysis showed excellent agreement. Because of the higher signal to noise ratio, the method shows increased sensitivity in our hands over single (CD55 or CD59) parameter analysis. Using this assay, we were able to detect as few as 1% PNH monocytes and neutrophils in aplastic anemia, that were otherwise undetectable using CD55 and CD59 on RBC's. We also observed abnormal FLAER staining of blast populations in acute leukemia. In these cases, the neutrophils stained normally with FLAER, while the gated CD33bright cells failed to express normal levels of CD14 and additionally showed aberrant CD45 staining and bound lower levels of FLAER. Conclusion: FLAER combined with multiparameter flow cytometry offers an improved assay for diagnosis and monitoring of PNH clones and may have utility in detection of unsuspected myeloproliferative disorders. © 2007 Clinical Cytometry Society [source] Routine immunophenotyping in acute leukemia: Role in lineage assignment and reassignmentCYTOMETRY, Issue 5 2006Misbah Qadir Abstract Diagnostic evaluation of acute leukemia at Roswell Park Cancer Institute has routinely included immunophenotyping by multiparameter flow cytometry. In a retrospective analysis of 646 cases, morphology and cytochemistry established lineage in 612, but not in 34 (5%), of which 26, 5, and 3 were myeloid, undifferentiated, and lymphoid, respectively, based on immunophenotyping. In addition, immunophenotyping changed the lineage assigned based on morphology and cytochemistry in 11 cases (2%); 8 changed from lymphoid to myeloid, and 3 from myeloid to lymphoid. The data support routine inclusion of at least limited immunophenotyping in the diagnostic evaluation of acute leukemia. © 2006 International Society for Analytical Cytology [source] Flow cytometric measurement of circulating endothelial cells: The effect of age and peripheral arterial disease on baseline levels of mature and progenitor populationsCYTOMETRY, Issue 2 2006Rebecca Gusic Shaffer Abstract Background: Age and cardiovascular disease status appear to alter numbers and function of circulating endothelial progenitor cells (EPCs). Despite no universal phenotypic definition, numerous studies have implicated progenitors with apparent endothelial potential in local responses to vascular injury and with cardiovascular disease in general. To further define the role of this lineage in peripheral artery disease (PAD), we developed a multiparameter flow cytometry assay to analyze multiple phenotypic definitions of progenitor cells (PCs), EPCs, and mature endothelial cells (ECs) and evaluate effects of age and PAD on baseline levels of each subset. Methods: Blood was collected from young healthy subjects (N = 9, mean age 33 ± 8 years), older healthy subjects (N = 13, mean age 66 ± 8 years), and older subjects with PAD (N = 15, mean age 69 ± 8 years). After ammonium chloride lysis, cells were stained and analyzed on a Becton-Dickinson LSR II with a 5-color antibody panel: FITC-anti-CD31, PE-anti-CD146, PE-anti-CD133, PerCP-Cy5.5-anti-CD3,-CD19,-CD33 (lineage panel), PE-Cy7-anti-CD34, and APC-anti-VEGF-R2. Viability was assessed by propidium iodide exclusion, and only viable, low to medium side scatter lineage-negative singlets were analyzed. In some studies, cells were sorted for morphological studies. Subsets were defined as indicated later. Results: Our results, using a comprehensive flow cytometric panel, indicate that CD133+, CD34+, and CD133+/CD34+ PCs are elevated in younger healthy individuals compared to older individuals, both healthy and with PAD. However, the number of EPCs and mature ECs did not significantly differ among the three groups. Assessment of endothelial colony forming units and dual acLDL-lectin staining supported the flow cytometric findings. Conclusions: We describe a comprehensive flow cytometric method to detect circulating mature and progenitor endothelial populations confirmed by conventional morphological and functional assays. Our findings suggest that aging may influence circulating levels of PCs, but not EPCs or ECs; PAD had no effect on baseline levels of any populations investigated. This study provides the basis for evaluating the potential effects of acute stress and therapeutic intervention on circulating progenitor and endothelial populations as a biomarker for cardiovascular status. © 2005 International Society for Analytical Cytology [source] Clinical utility of CD23 and FMC7 antigen coexistent expression in B-cell lymphoproliferative disorder subclassificationCYTOMETRY, Issue 1 2002Ejaz Ahmad Abstract Background: CD23 and FMC7 are normal B-cell antigens utilized during diagnostic immunophenotyping of suspected lymphoproliferative disorders. However, the diagnostic utility of coexistent antigenic expression patterns with simultaneous two-color staining and flow cytometric analysis has not been studied extensively. Methods: Using multiparameter flow cytometry, we evaluated the expression pattern of FMC7 and CD23 in 218 cases of B-cell lymphoma from blood and bone marrow specimens. Results: The CD23(+)/FMC7(-) pattern was the most common pattern in patients with chronic lymphocytic leukemia and related variants. The widest variation of patterns was found in patients with follicular cell lymphoma, large cell lymphoma, and Waldenström's macroglobulinemia, a lymphoplasmacytoid disorder, although most cases expressed the CD23-/FMC7(+) pattern. The CD23 and FMC7 antigen, along with the CD5 coexpression pattern, provides critical adjunctive data. These data allow accurate classification of the majority of cases, thereby providing a key aspect of a reliable diagnostic algorithm. The CD23 and FMC7 antigen expression pattern, along with selected other antigens, was predictive of subtypes in >95% of lymphoproliferative cases and narrowed the differential diagnosis in the remaining cases. Conclusion: The flow cytometric CD23/FMC7 expression pattern achieved by multicolor immunophenotyping facilitates accurate and reproducible classification of B-cell lymphomas and has diagnostic utility. Cytometry (Clin. Cytometry) 50:1,7, 2002. © 2002 Wiley-Liss, Inc. [source] A chromatic explosion: the development and future of multiparameter flow cytometryIMMUNOLOGY, Issue 4 2008Pratip K. Chattopadhyay Summary Multiparameter flow cytometry has matured tremendously since the 1990s, giving rise to a technology that allows us to study the immune system in unprecedented detail. In this article, we review the development of hardware, reagents, and data analysis tools for multiparameter flow cytometry and discuss future advances in the field. Finally, we highlight new applications that use this technology to reveal previously unappreciated aspects of cell biology and immunity. [source] CD146-based immunomagnetic enrichment followed by multiparameter flow cytometry: a new approach to counting circulating endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2008A. WIDEMANN Summary.,Background: Circulating endothelial cells (CECs) have emerged as non-invasive biomarkers of vascular dysfunction. The most widely used method for their detection is CD146-based immunomagnetic separation (IMS). Although this approach has provided consensus values in both normal and pathologic situations, it remains tedious and requires a trained operator. Objectives: Our objective was to evaluate a new hybrid assay for CEC measurement using a combination of pre-enrichment of CD146+ circulating cells and multiparametric flow cytometry measurement (FCM). Patients and methods: CECs were determined in peripheral blood from 20 healthy volunteers, 12 patients undergoing coronary angioplasty, and 30 renal transplant recipients, and blood spiked with cultured endothelial cells. CD146+ cells were isolated using CD146-coated magnetic nanoparticles and labeled using CD45,fluorescein isothiocyanate and CD146,PE or isotype control antibody and propidium iodide before FCM. The same samples were also processed using CD146-based immunomagnetic separation as the reference method. Results: The hybrid assay detected CECs, identified as CD45dim/CD146bright/propidium iodide+, with high size-related scatter characteristics, and clearly discriminated these from CD45bright/CD146dim activated T lymphocytes. The method demonstrated both high recovery efficiency and good reproducibility. Both IMS and the hybrid assay similarly identified increased CEC levels in patients undergoing coronary angioplasty and renal transplantation, when compared to healthy controls. In patients, CEC values from these two methods were of the same order of magnitude and highly correlated. Bland,Altman analysis revealed poor statistical agreement between methods, flerrofluid,FCM providing higher values than IMS. Conclusion: This new hybrid FCM assay constitutes an accurate alternative to visual counting of CECs following CD146-based IMS. [source] Quantitative specificity-based display library screening identifies determinants of antibody-epitope binding specificity,PROTEIN SCIENCE, Issue 9 2009Sejal S. Hall Abstract Despite the critical importance of molecular specificity in bimolecular systems, in vitro display technologies have been applied extensively for affinity maturation of peptides and antibodies without explicitly measuring the specificity of the desired interaction. We devised a general strategy to measure, screen, and evolve specificity of protein ligand interactions analogous to widely used affinity maturation strategies. The specificity of binding to target and nontarget antibodies labeled with spectrally distinct fluorophores was measured simultaneously in protein mixtures via multiparameter flow cytometry, thereby enabling screening for high target antibody specificity. Isolated antibody specific ligands exhibited varying specificity, revealing critical amino acid determinants for target recognition and nontarget avoidance in complex mixtures. Molecular specificity in the mixture was further enhanced by quantitative directed evolution, yielding a family of epitopes exhibiting improved specificities equivalent, or superior to, the native peptide antigen to which the antibody was raised. Specificity screening simultaneously favored affinity, yielding ligands with three-fold improved affinity relative to the parent epitope. Quantitative specificity screening will be useful to screen, evolve, and characterize the specificity of protein and peptide interactions for molecular recognition applications. [source] Reactivity with dichotomous determinants of Ro 60 stratifies autoantibody responses in lupus and primary Sjögren's syndromeARTHRITIS & RHEUMATISM, Issue 5 2010Joanne H. Reed Objective Analysis of B cell determinants of Ro 60 exposed on the surface of apoptotic cells (apotopes) or intracellular epitopes provides insight into the structural forms of the autoantigen that break immune tolerance. This study was initiated to compare anti,Ro 60 responses in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS) against membrane-bound and intracellular forms of Ro 60. Methods The reactivity of autoantibodies from patients with SLE and primary SS to Ro 60 apotopes and epitopes was assessed by multiparameter flow cytometry and solid-phase immunoassay. Anti,Ro 60 IgG was eluted from early apoptotic cells or recombinant Ro 60 immobilized on nitrocellulose, and binding to membrane-bound and intracellular forms of Ro 60 was quantitated by flow cytometry. Results An immunodominant apotope, which was recognized by IgG from a subset of SLE patients with anti-Ro, but not anti-La, autoantibodies, was mapped to a region forming a helix-loop-helix at the apical tip of the Ro 60 molecule. Immobilization of this region to the solid phase exposed an epitope that was recognized by IgG from primary SS and SLE patients whose sera had both anti-Ro and anti-La autoantibodies. Autoantibodies eluted from either the surface of apoptotic cells or the Ro 60 epitope on the solid phase were non,cross-reactive and specifically recognized membrane-bound or cytoplasmic forms of Ro 60. Conclusion This is the first example of a dichotomy of human autoantibody responses against mutually exclusive determinants linked to a single domain of a systemic autoantigen and supports a model in which tolerance is broken by different immunogenic forms of Ro 60. [source] Systemic activation of the immune system induces aberrant BAFF and APRIL expression in B cells in patients with systemic lupus erythematosusARTHRITIS & RHEUMATISM, Issue 7 2009Van Trung Chu Objective Elevated levels of BAFF and APRIL are characteristic of patients with systemic lupus erythematosus (SLE). The reasons for enhanced cytokine production are not well understood. This study was undertaken to identify the cells responsible for the overproduction of these cytokines. Methods BAFF expression was analyzed on peripheral blood mononuclear cells by multiparameter flow cytometry and in tissue samples by immunofluorescence staining. The levels of BAFF and APRIL mRNA were quantified in sorted B cells. In vitro cultures were used to analyze whether B cell survival and differentiation was supported by autocrine BAFF and/or APRIL. Results Aberrant activation of B cells in patients with SLE was associated with a significant up-regulation of BAFF expression in naive, memory, and plasma cells. Furthermore, strong expression of BAFF and APRIL was found in plasma cells from the lymph node, bone marrow, and kidney. The levels of BAFF and APRIL mRNA in CD19+ B cells correlated both with the titer of anti-double stranded DNA antibodies and with the SLE Disease Activity Index. In vitro experiments demonstrated that B cells released functional BAFF/APRIL upon activation. Conclusion Our data show that B cells contribute to the enhanced levels of circulating BAFF and APRIL. The aberrant up-regulation of these cytokines may initiate a vicious circle in which enhanced levels of BAFF and APRIL act in an autocrine manner to reinforce the systemic activation of the humoral immune system. [source] Ro 60 functions as a receptor for ,2 -glycoprotein I on apoptotic cellsARTHRITIS & RHEUMATISM, Issue 3 2009Joanne H. Reed Objective The autoantigens 60-kd Ro/SSA (Ro 60) and ,2 -glycoprotein I (,2GPI) are both displayed on the surface membrane of apoptotic cells. Epitope-spreading experiments have suggested that these autoantigens may be present as a complex on the apoptotic cell surface. This study was undertaken to investigate whether ,2GPI interacts with Ro 60 on apoptotic cells and alters the binding of anti,Ro 60 IgG. Methods The interaction between soluble recombinant Ro 60 fragments and ,2GPI was investigated in vitro by direct and saturation binding assays using native human ,2GPI and recombinant domain deletion mutants. Binding of ,2GPI to early and late apoptotic cells was assessed by multiparameter flow cytometry, and specificity of binding was determined by competitive inhibition with soluble recombinant Ro 60 and anti,Ro 60 IgG. Results The Ro 60 fragment expressing a surface-exposed epitope (apotope) bound with high affinity (Kd = ,15 nM) to domain V of ,2GPI in vitro. Beta2 -glycoprotein I bound to the surface of apoptotic cells in a dose-dependent manner and was blocked by the Ro 60 apotope fragment. In reciprocal competitive inhibition studies, ,2GPI blocked the binding of anti,Ro 60 autoantibodies to apoptotic cells in a dose-dependent manner, and anti,Ro 60 IgG inhibited the binding of ,2GPI. Moreover, ,2GPI showed a 2-fold increase in binding to apoptotic cells that overexpress Ro 60 on the surface. Conclusion These results demonstrate that Ro 60 functions as a novel receptor for ,2GPI on the surface of apoptotic cells. The formation of Ro 60,,2GPI complexes may protect against anti,Ro 60 autoantibody,mediated tissue injury. [source] Increased numbers of circulating polyfunctional Th17 memory cells in patients with seronegative spondylarthritidesARTHRITIS & RHEUMATISM, Issue 8 2008Camilla Jandus Objective A distinct subset of proinflammatory CD4+ T cells that produce interleukin-17 was recently identified. These cells are implicated in different autoimmune disease models, such as experimental autoimmune encephalomyelitis and collagen-induced arthritis, but their involvement in human autoimmune disease has not yet been clearly established. The purpose of this study was to assess the frequency and functional properties of Th17 cells in healthy donors and in patients with different autoimmune diseases. Methods Peripheral blood was obtained from 10 psoriatic arthritis (PsA), 10 ankylosing spondylitis (AS), 10 rheumatoid arthritis (RA), and 5 vitiligo patients, as well as from 25 healthy donors. Synovial tissue samples from a separate group of patients were also evaluated (obtained as paraffin-embedded sections). Peripheral blood cells were analyzed by multiparameter flow cytometry and immunohistochemistry. Cytokine production was examined by enzyme-linked immunosorbent assay and intracellular cytokine staining using specific monoclonal antibodies. Synovial tissue was examined for infiltrating T cells by immunohistochemical analysis. Results We found increased numbers of circulating Th17 cells in the peripheral blood of patients with seronegative spondylarthritides (PsA and AS), but not in patients with RA or vitiligo. In addition, Th17 cells from the spondylarthritis patients showed advanced differentiation and were polyfunctional in terms of T cell receptor,driven cytokine production. Conclusion These observations suggest a role of Th17 cells in the pathogenesis of certain human autoimmune disorders, in particular the seronegative spondylarthritides. [source] | ||||||||||