Quantitative Flow Cytometry Can Predict Childhood Acute Lymphoblastic Leukaemia Presenting with Aplasia

Atra, Ayad; Abboudi, Zaid; Farahat, Nahla; Catovsky, Daniel

doi:10.3109/10428199709068284

Cited by 4 publications

(5 citation statements)

References 4 publications

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“…Estimation of specific antigen numbers had been described as an useful diagnostic or prognostic tool in various diseases (2)(3)(4). Numerous publications support the relevance of FI determination in diagnostic, differential diagnosis, prognostic evaluation, and therapy monitoring of leukemias and lymphomas (5)(6)(7)(8)(9)(10)(11)(12).…”

Section: Introductionmentioning

confidence: 99%

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Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemia

Rossmann

Lenkei

Lundin

et al. 2007

Cytometry Part B Clinical

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Background: The fluorescence intensities of CD3, CD4 on T cells and CD20, CD22 molecules on B cells were quantitatively measured on lymphocytes from chronic lymphocytic leukemia (CLL) patients and healthy donors.Methods: The performance of three different types of microbeads was compared, i.e. Quantum molecules of equivalent soluble fluorochrome (Q-MESF), Quantum simply cellular (QSC), and QuantiBRITE TM (QB). As all PE-conjugates had a F/P ratio of 1:1, the MESF units represented also the antibody binding capacity (ABC).Results: The ABCs of CD4 and CD20 antigens estimated with QSC (ABC QSC ) were higher than those assigned with QB (ABC QB ) with an average difference 49%. Higher numbers of antigenic sites were obtained with Q-MESF than with QSC for CD20 antigen. On the contrary, CD4 antigenic sites numbers estimated with QSC were higher than those estimated with Q-MESF. ABC values estimated with Quantum MESF PE (ABC Q-MESF ) were *15% higher than ABC QSC , whereas ABC Q-MESF was *49% higher than ABC QB INTRODUCTIONQuantitative measurements of fluorescence intensity by flow cytometry (QFCM) assess the numbers of monoclonal antibody (mAb) molecules bound to a cell. The fluorescence intensity (FI) of staining correlates to the number of fluorochrome conjugated mAb molecules bound to the cell, and consequently, the amount of receptors on the cell. Thus, the number of antigen receptors can be determined by QFCM, through estimation of the exact numbers of bound fluorescent antibody molecules, provided that appropriate standards and fluorescence controls are tested in parallel and reagents in saturating amounts are used. In addition, the process of quantitation facilitates standardization and quality control (1).

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Section: Introductionmentioning

confidence: 99%

“…Numerous publications support the relevance of FI determination in diagnostic, differential diagnosis, prognostic evaluation, and therapy monitoring of leukemias and lymphomas (5)(6)(7)(8)(9)(10)(11)(12).…”

Section: Introductionmentioning

confidence: 99%

Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemia

Rossmann

Lenkei

Lundin

et al. 2007

Cytometry Part B Clinical

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“…Abnormally dim CD22 expression is characteristic of chronic lymphocytic leukemia (CLL) while abnormally bright CD22 expression is typical in hairy cell leukemia. In several studies, determining the degree of antigen expression is useful in diagnosis, prognostication, and monitoring of therapy in leukemias and lymphomas (1)(2)(3). Furthermore, the increased use of antibody-based therapy in hematolymphoid neoplasia has raised interest in correlating levels of expression of the targeted antigen (e.g., CD52 in Campath therapy) with response to therapy.…”

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confidence: 99%

Variables affecting the quantitation of CD22 in neoplastic B cells

Jasper

Arun

Venzon

et al. 2010

Cytometry Part B Clinical

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Background: Quantitative flow cytometry (QFCM) is being applied in the clinical flow cytometry laboratory for diagnosis, prognosis, and assessment of patients receiving antibody-based therapy. ABC values and the effect of technical variables on CD22 quantitation in acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), follicular lymphoma (FCL), hairy cell leukemia (HCL) and normal B cells were studied.Methods: The QuantiBrite System V R was used to determine the level of CD22 expression (mean antibody bound per cell, ABC) by malignant and normal B cells. The intra-assay variability, number of cells required for precision, effect of delayed processing as well as shipment of peripheral blood specimens (delayed processing and exposure to noncontrolled environments), and the effect of paraformaldehyde fixation on assay results were studied.Results: The QuantiBRITE method of measuring CD22 ABC is precise (median CV 1.6%, 95% confidence interval, 1.2-2.3%) but a threshold of 250 malignant cells is required for reliable CD22 ABC values. Delayed processing and overnight shipment of specimens resulted in significantly different ABC values whereas fixation for up to 12 h had no significant effect. ABC measurements determined that CD22 expression is lower than normal in ALL, CLL, FCL, and MCL but higher than normal in HCL.Conclusions: CD22 expression was atypical in the hematolymphoid malignancies studied and may have diagnostic utility. Technical variables such as cell number analyzed and delayed processing or overnight shipment of specimens impact significantly on the measurement of antigen expression by QFCM in the clinical laboratory. Published

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“…This suggests that the use of the combined assessment of these markers by QFC may distinguish more precisely between normal and leukemic B-precursors than the nonquantitative methods of flow cytometry, especially in the analysis of samples from children, who present a high percentage of normal B-precursors in BM that mimic the immunophenotypic features of ALL (11,32). Moreover, the approach described here may be useful in those cases of ALL presenting with pancytopenia, a condition of difficult diagnosis by morphological analysis alone (17,18).…”

Section: Discussionmentioning

confidence: 97%

“…The introduction of quantitative fluorescence cytometry (QFC) techniques allowed quantifying antigen expression in an accurate and reproducible manner (13,14) and previous reports have suggested that leukemic cells may express antigens at densities distinct from those presented by their normal counterparts (4,15,16). This method may be useful for MRD detection, as well as for the diagnosis of ALL, especially in those cases preceded by transient pancytopenia, a presentation more common in children and of difficult diagnosis (17,18).…”

Section: Introductionmentioning

confidence: 99%

Immunophenotype of normal and leukemic bone marrow B-precursors in a Brazilian population. A comparative analysis by quantitative fluorescence cytometry

Rego

Garcia

Carneiro

et al. 2001

Braz J Med Biol Res

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The distinction between normal and leukemic bone marrow (BM) Bprecursors is essential for the diagnosis and treatment monitoring of acute lymphoblastic leukemia (ALL). In order to evaluate the potential use of quantitative fluorescence cytometry (QFC) for this distinction, we studied 21 normal individuals and 40 patients with CD10 + ALL. We characterized the age-related changes of the CD10, CD19, TdT, CD34 and CD79a densities in normal and leukemic BM. Compared to normal adults, the B-precursors from normal children expressed significantly lower values of CD34-specific antibody binding capacity (SABC) (median value of 86.6 vs 160.2 arbitrary units (a.u.) in children and adults, respectively). No significant age-related difference was observed in the expression of the other markers in the normal BM, or in any of the markers in the leukemic BM. Based on the literature, we set the cut-off value for the normal CD10 expression at 45 x 10 3 a.u. for both age groups. For the remaining markers we established the cut-off values based on the minimum-maximum values in the normal BM in each age group. The expression of CD10 was higher than the cut-off in 30 ALL cases and in 18 of them there was a concomitant aberrant expression of other markers. In 9 of the 10 CD10 + ALL with normal CD10 SABC values, the expression of at least one other marker was aberrant. In conclusion, the distinction between normal and leukemic cells by QFC was possible in 38/40 CD10 + ALL cases.

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Quantitative Flow Cytometry Can Predict Childhood Acute Lymphoblastic Leukaemia Presenting with Aplasia

Cited by 4 publications

References 4 publications

Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemia

Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemia

Variables affecting the quantitation of CD22 in neoplastic B cells

Immunophenotype of normal and leukemic bone marrow B-precursors in a Brazilian population. A comparative analysis by quantitative fluorescence cytometry

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