Development and Evaluation of a Novel Flow Cytometric Assay for Determination of Fcγ Receptor IIIa-158 V/F Dimorphism.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1366-1366
Author(s):  
Sebastian Boettcher ◽  
Matthias Ritgen ◽  
Christiane Pott ◽  
Andreas Humpe ◽  
Michael Kneba
Keyword(s):  
Flow Cytometry ◽  
Nk Cells ◽  
Single Agent ◽  
Amino Acid Position ◽  
Taqman Assay ◽  
Flow Cytometric Assay ◽  
Fcγ Receptor ◽  
Color Flow ◽  
Flow Cytometric

Abstract A recently described dimorphism at position 559 of FCGR3A gene results in two allotypes of Fcγ receptor IIIa (Fcγ RIIIa) with phenylalanine (F) or valine (V) at amino acid position 158. It has been shown that Fcγ RIIIa-VV homozygous patients with follicular lymphoma respond better to Rituximab as a single agent than F carriers. However, there is evidence that this disadvantage in F carriers can be overcome by higher Rituximab concentrations or by the use of defucosylated therapeutic antibodies. Therefore rapid, widely applicable, and cost-effective methods for the determination of this Fcγ RIIIa dimorphism are necessary. Currently available methods to determine this dimorphism are based on PCR techniques. To simplify the determination of Fcγ RIIIa-V/F dimorphism we developed a novel flow cytometric approach using known differences in epitope recognition of monoclonal antibodies (moabs) to Fcγ RIIIa. The moab MEM-154 recognizes Fcγ RIIIa-V only, whereas moab 3G8 recognizes Fcγ RIIIa irrespective of the dimorphism. We determined the expression level of epitopes recognized by 3G8 and MEM-154 in NK cells of 35 healthy donors (FF 14; V/F 17; VV 4) by three color flow cytometry and secondary immunofluorescence. Results were compared to genotypes determined by a TaqMan assay using allele specific fluorochrome labelled probes. Donors genotyped as Fcγ RIIIa FF, V/F, and VV demonstrated overlapping immunofluorescence levels detected by both 3G8 and MEM-154. However, the ratio of fluorescence measured using MEM-154 divided by the immunofluorescence measured using 3G8 was 100% accurate for predicting genotypes. Ratios below 0.05 were measured in Fcγ RIIIa FF individuals, ratios between 0.1 and 0.5 were measured in heterozygotes, whereas ratios higher than 0.6 were found in Fcγ RIIIa VV individuals only. Quantitative flow cytometry demonstrated a great variation in Fcγ RIIIa expression on NK cells between individuals with identical Fcγ R IIIa genotype explaining the failure to predict the genotype by a single Fcγ R IIIa moab only. This novel flow cytometric assay is cost-efficient, easy to implement, reliable and uses standard flow cytometric techniques. Compared to known methods to determine the dimorphism it is faster and applicable in laboratories without sophisticated PCR technology.

scholarly journals Identification and Characterization of Bacillus anthracis Spores by Multiparameter Flow Cytometry

2008 ◽  
Vol 74 (16) ◽  
pp. 5220-5223 ◽  
Author(s):  
William C. Schumacher ◽  
Craig A. Storozuk ◽  
Prabir K. Dutta ◽  
Andrew J. Phipps
Keyword(s):  
Flow Cytometry ◽  
Bacillus Anthracis ◽  
Protective Antigen ◽  
Multiparameter Flow Cytometry ◽  
Flow Cytometric Assay ◽  
Color Flow ◽  
Flow Cytometric ◽  
Bacillus Anthracis Spores ◽  
Identification And Characterization

ABSTRACT In response to the need for methods that can rapidly detect potentially virulent Bacillus anthracis spores, we developed a two-color flow cytometric assay capable of simultaneously identifying B. anthracis spores and the presence of spore-associated protective antigen, a virulence marker for strains harboring the pXO1 plasmid.

Immunophenotypic Study of Basophils by Multiparameter Flow Cytometry

2008 ◽  
Vol 132 (5) ◽  
pp. 813-819
Author(s):  
Xiaohong Han ◽  
Jeffrey L. Jorgensen ◽  
Archana Brahmandam ◽  
Ellen Schlette ◽  
Yang O. Huh ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Chronic Myelogenous Leukemia ◽  
Peripheral Blood ◽  
Myelogenous Leukemia ◽  
Multiparameter Flow Cytometry ◽  
Color Flow ◽  
Aberrant Expression ◽  
Flow Cytometric ◽  
Hla Dr

Abstract Context.—The immunophenotypic profile of basophils is not yet fully established, and the immunophenotypic changes in chronic myelogenous leukemia are not fully characterized. Objective.—To establish a comprehensive immunophenotypic spectrum of normal basophils and to assess the range of immunophenotypic aberrations of basophils in chronic myelogenous leukemia. Design.—Using 4-color flow cytometry, we compared the immunophenotypic profile of basophils in peripheral blood or bone marrow samples from 20 patients with no evidence of neoplasia to basophils from 15 patients with chronic myelogenous leukemia. Results.—Basophils in control cases were all positive for CD9, CD13, CD22, CD25 (dim), CD33, CD36, CD38 (bright), CD45 (dimmer than lymphocytes and brighter than myeloblasts), and CD123 (bright), and were negative for CD19, CD34, CD64, CD117, and HLA-DR. Basophils in all chronic myelogenous leukemia patients possessed 1 to 5 immunophenotypic aberrancies. The most common aberrancies were underexpression of CD38, followed by aberrant expression of CD64 and underexpression of CD123. CD34 and CD117 were present in cases with basophilic precursors. Myeloblasts showed a distinct immunophenotypic profile, as they typically expressed CD34 and CD117, showed dimmer expression (compared with basophils) of CD38, CD45, and CD123, and lacked expression of CD22. Conclusions.—Flow cytometric immunophenotyping can identify immunophenotypic aberrations of basophils in chronic myelogenous leukemia, and discriminate basophils from myeloblasts.

scholarly journals CD161 Is Expressed in a Subset of T-Cell Prolymphocytic Leukemia Cases and Is Useful for Disease Follow-up

2019 ◽  
Vol 152 (4) ◽  
pp. 471-478
Author(s):  
Scott R Gilles ◽  
Sophia L Yohe ◽  
Michael A Linden ◽  
Michelle Dolan ◽  
Betsy Hirsch ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cell ◽  
Nk Cells ◽  
Retrospective Review ◽  
T Cell Subsets ◽  
Prolymphocytic Leukemia ◽  
Flow Cytometry Data ◽  
Flow Cytometric ◽  
Flow Cytometric Evaluation

AbstractObjectivesCD161 (NKRP1) is a lectin-like receptor present on NK cells and rare T-cell subsets. We have observed CD161 expression in some cases of T-cell prolymphocytic leukemia (T-PLL) and found it to be useful in follow-up and detection of disease after treatment.MethodsRetrospective review of T-PLL cases with complete flow cytometry data including CD161.ResultsWe identified 10 cases of T-PLL with flow cytometric evaluation of CD161 available. Six of these cases were positive for CD161 expression. All CD161-positive cases were positive for CD8 with variable CD4 expression, whereas all CD161-negative cases were negative for CD8. In a case with two neoplastic subsets positive and negative for CD8, only the former expressed CD161.ConclusionsThese novel results suggest that CD161 is often aberrantly expressed in a defined subset of T-PLL positive for CD8. We are showing the utility of this immunophenotype in diagnosis and follow-up.

scholarly journals Flow cytometric analysis of herpes simplex virus type 1 susceptibility to acyclovir, ganciclovir, and foscarnet.

1997 ◽  
Vol 41 (12) ◽  
pp. 2686-2692 ◽  
Author(s):  
I Pavić ◽  
A Hartmann ◽  
A Zimmermann ◽  
D Michel ◽  
W Hampl ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cytopathic Effect ◽  
Flow Cytometric Analysis ◽  
Flow Cytometric ◽  
Resistant Strains ◽  
Simplex Virus

We established a quantitative flow cytometric method for determination of herpes simplex virus type 1 (HSV-1) susceptibility to acyclovir (ACV), ganciclovir, and foscarnet in vitro. Susceptibility was defined in terms of the drug concentration which reduced the number of cells expressing HSV-1 glycoprotein C (gpC) with a fluorescence intensity of > or =10(2) by 50% (IC50). Flow cytometry allowed us to use a high (1.0) as well as a low (0.005) multiplicity of infection, and determination of the IC50 was possible after one or more viral replicative cycles. IC50s were dependent on virus input and on time postinfection. In mixture experiments, 1 to 2% resistant viruses added to a sensitive strain could be detected. The results obtained by flow cytometry showed a good qualitative correlation with those achieved by cytopathic effect inhibitory assay. However, flow cytometry might detect more quantitative differences in drug susceptibility, especially among resistant strains, as confirmed also by determination of intracellular drug phosphorylation. The mean IC50s for ACV-sensitive strains were 0.45 to 1.47 microM, and those for ACV-resistant strains were between 140 and 3,134 microM. Flow cytometric analysis was fast and accurate, automatizable, and highly reproducible. Flow cytometry may be a more powerful tool than standard cytopathic effect-based assays and could have advantages for the detection of low levels of drug resistance or mixtures of sensitive and resistant virus strains.

Aspirin Does Not Affect the Flow Cytometric Detection of Fibrinogen Binding to, or Release of α-Granules or Lysosomes from, Human Platelets

1994 ◽  
Vol 87 (5) ◽  
pp. 575-580 ◽  
Author(s):  
Nicolas A. F. Chronos ◽  
Darren J. Wilson ◽  
Sarah L. Janes ◽  
Ronald A. Hutton ◽  
Nigel P. Buller ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Arachidonic Acid ◽  
Thromboxane A2 ◽  
Normal Subjects ◽  
Human Platelets ◽  
Aspirin Therapy ◽  
Flow Cytometric Assay ◽  
Blood Samples ◽  
Flow Cytometric ◽  
Fibrinogen Binding

1. Aspirin inhibits the conversion of arachidonic acid to thromboxane A2 which reinforces the effects of weak agonists such as ADP in platelets. 2. In this study the effect of aspirin (300 mg/day) on platelet agonist response was measured by whole blood flow cytometry of unfixed blood samples from normal subjects (n = 10), an assay that investigates aggregation-independent changes in the platelet. 3. Fibrinogen binding to unstimulated platelets or to platelets stimulated with ADP or thrombin was unaffected by aspirin. 4. Under the conditions of this assay, platelets undergo a partial degranulation of α-granules and lysosomes (evidenced by expression of P-selectin and CD63, respectively) in response to ADP, and full degranulation in response to thrombin. P-selectin expression was paralleled by release of β-thromboglobulin. None of these events was affected by aspirin. 5. Thromboxane formation was totally prevented by the aspirin treatment, as shown by Born aggregometry in which the platelet aggregatory response to arachidonic acid was abolished and secondary aggregation by ADP was inhibited. 6. The flow cytometric assay can therefore be used to investigate platelets in patients, regardless of aspirin therapy. 7. These findings suggest that platelet fibrinogen binding and the release of platelet α-granule and lysosomal contents, in response to stimulation with physiological agonists, can continue in patients despite aspirin therapy. This may help to explain why aspirin is only partially effective in preventing thrombotic events.

scholarly journals A flow cytometric assay of neutrophil degranulation.

1983 ◽  
Vol 31 (6) ◽  
pp. 737-744 ◽  
Author(s):  
W R Abrams ◽  
L W Diamond ◽  
A B Kane
Keyword(s):  
Flow Cytometry ◽  
Fluorescence Intensity ◽  
Ionophore A23187 ◽  
Flow Cytometric Assay ◽  
Elastase Activity ◽  
Flow Cytometric ◽  
Specific Granules ◽  
Neutrophil Degranulation ◽  
High Fluorescence Intensity ◽  
High Fluorescence

A quantitative assay of neutrophil degranulation was developed using flow cytometry. Dog neutrophils were purified to greater than 95% purity and viability by isopyknic density centrifugation in an isosmotic medium. These cells concentrated the fluorochrome acridine orange (AO) in their azurophilic granules, but not in specific granules. Also contained in the azurophilic granules are elastase, myeloperoxidase, and approximately 50% of the lysozyme activity. The fluorochrome was released concomitantly with elastase activity, as shown by flow cytometry, fluorescence microscopy, and biochemical assay in response to the ionophore A23187. By flow cytometry, unstimulated cells are distributed in a single broad peak of high fluorescence intensity. With increasing concentrations of A23187 (0.48-4.80 microM), a greater proportion of the cells shifted to a single peak of low fluorescence intensity. Few cells with intermediate fluorescence were observed. These analyses revealed that the neutrophils degranulated in a quantal, all-or-none response.

A New Algorithm and Panel Construction for Pediatric Leukemia Immunophenotyping Using 10-Color Flow Cytometry

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4799-4799
Author(s):  
Bettina Keller ◽  
Markus P Radsak ◽  
Joerg Faber ◽  
Alexandra Russo
Keyword(s):  
Flow Cytometry ◽  
Childhood Leukemia ◽  
Conflicts Of Interest ◽  
High Reliability ◽  
Maturation Stage ◽  
Specific Information ◽  
Color Flow ◽  
Pediatric Leukemia ◽  
Flow Cytometric

Abstract Abstract 4799 Background: Rapid identification and quantification of abnormal cell populations in minimal specimen are crucial for diagnosis and longitudinal minimal residual disease (MRD) testing of childhood leukemia. So far, most standard immunophenotypic analyses are performed using antibody panels with up to five-colors and require high cell numbers. For infant and pediatric specimen, high-level multicolor analyses is highly desirable to gather sufficient data for initial diagnostic and follow up monitoring of pathologic populations. Objective: In this study, we aimed to establish a newly defined pediatric multicolor flow cytometric panel algorithm with high reliability yet minimal specimen requirement. Results: We defined a 10-color flow cytometric panel using the new violet laser dye “KromeOrange (KO)”. Applying CD45-KO/Side Scatter gating, combined with 2 additional backbone markers the panel is designed in two consecutive steps. In the first step, a single standardized 10-color-“screening tube” (FITC-HLA-DR, PE-CD15/CD56, ECD-CD5, PC5.5-CD33, PC7-CD13, APC-CD117, APC A700-CD34, APC A750-CD19, PB-CD3, KrO-CD45) is applied for initial orientation of specific lineage assignment. Based on results obtained with the screening tube, a specific multi-tube “classification panel” is used to complete detailed characterization of lineage specific malignancy and maturation stage. Suitable specimens include fresh blood, bone marrow and all body fluids. All samples are stained directly with monoclonal antibodies, followed by the lyses of erythrocytes and a short wash. Compared to standard five color panel previously used the application of greater numbers of informative antibodies in the screening tube and in the 2ndstep muti-tube classification panel is cost and time efficient and results in a more precise characterization of any single event. Conclusion: Our panel construction and algorithm definition for infant and pediatric leukemia immunophenotyping is one of the first 10-color flow cytometry panels described for this application. Advantages are the possibility to obtain highly specific information from minimal specimens with significantly improved laboratory efficiency. The overall performance is currently tested in a routine clinical setting. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Use of Flow Cytometry To Monitor Legionella Viability

2008 ◽  
Vol 74 (24) ◽  
pp. 7813-7816 ◽  
Author(s):  
Séverine Allegra ◽  
Françoise Berger ◽  
Philippe Berthelot ◽  
Florence Grattard ◽  
Bruno Pozzetto ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Heat Shock ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Flow Cytometric Assay ◽  
Viable But Nonculturable ◽  
Flow Cytometric

ABSTRACT Legionella viability was monitored during heat shock treatment at 70°C by a flow cytometric assay (FCA). After 30 min of treatment, for 6 of the 12 strains tested, the FCA still detected 10 to 25% of cells that were viable but nonculturable (VBNC). These VBNC cells were able to produce ATP and to be resuscitated after culture on amoebae.

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