ABSTRACT
Pediatric small round cell tumors (PSRCTs) constitute a large proportion of childhood malignancies with overlapping diagnostic and clinical features but radically different therapies. Here, we report a case of 16-year-old male child presenting with diffuse abdominal and mediastinal mass, axillary lymphadenopathy, and pleural effusion. Bone marrow aspirate showed near total replacement by small round malignant cells. The bone marrow biopsy showed interstitial infiltration by malignant cells, which were CD45? CD3? CD20? MIC2+ FLI1+ and diagnosis of Ewing's sarcoma was established. In contrast, flowcytometric immunophenotyping of the bone marrow aspirate showed CD45? cells, which were CD19+ cytCD79a+ CD10+ CD81+ CD38+ HLA-DR+ CD22+ CD20? consistent with B-cell acute lymphoblastic leukemia (B-ALL). The extended immunostaining panel on bone marrow biopsy also showed positivity for cytCD79a, CD10, CD19, and BCL-2, whereas fluorescent in-situ hybridization for EWSR1 gene rearrangement was negative. Thus, a final diagnosis of CD45? FLI1+ MIC2+ B-ALL was established. Rare cases of CD45? B-ALL with immunoreactivity for MIC2 and Friend leukemia virus integration 1 (FLI1) have posed a diagnostic challenge for PSRCTs in the recent past. This case report highlights the role of multimodality approach in establishing a correct diagnosis in CD45? PSRCTs to ensure definitive therapy and better clinical outcome.
ABSTRACT
Objective To investigate the detectable significance of multiparameter flow cytometry (MFC) for the first visiting and minimal residual disease (MRD) in the patients with multiple myeloma .Methods MFC was used to identify the plasma cells by the expression of CD138 or CD38 antigen in 74 patients with multiple myeloma .By combining surface antigens like CD45 ,CD56 , CD19 ,CD20 ,CD117 and the cytoplasm Kappa and Lambda light chain ,the aberrant myeloma cells were differentiated from normal plasma cells .Results In the 44 first visiting cases ,the positive expression of CD138 can be detected in all cases ,while the expres‐sion of CD19 was negative and 42 cases (95% ) were negative or weak positive expression for CD45 .The detection rates of CD38 , CD56 ,CD20 and CD117 were 98% ,93% ,45% and 41% ,respectively .The cytoplasm Kappa and Lambda light chains were showed the limited expression .Of the patients with MM ,14 cases were used for evaluating the change of immunophenotype at first visiting and during the treatment process ,among them ,11 cases(79% ) appeared the changes in at least one of aberrant phenotypes .4 cases (29% ) had the significant enhancement of antigen marker fluorescence intensities after chemotherapy and 7 cases (50% ) had sig‐nificant decrease of antigen marker fluorescence intensities after chemotherapy .CD45 ,CD19 and cytoplasm immunoglobulin light chains were the most stable marker ,no obvious antigen marker changes were found during the treatment ,while there was a signifi‐cant antigen density change in 2 cases of CD38 (14% ) ,7 cases of CD56 (50% ) ,4 cases of CD20 (29% ) and 2 cases of CD117 (14% ) .Of the 30 cases for evaluating MRD immunophenotype ,the abnormal myeloma cells were detected in 25 cases .In 5 cases ,no expression of limited Kappa and Lambda light chains was found and the ratio of Kappa and Lambda was 0 .5 - 2 ,which were identi‐fied as negative for MRD .Conclusion The multiparameter flow cytometry has important significance in evaluating the diagnosis , therapeutical effect and prognosis .The detection by adopting cytoplasm immunoglobulin light chains can improve the accuracy in MRD detection .
ABSTRACT
Objetivo. Describir un protocolo estandarizado mediante citometría de flujo para cuantificar en términos absolutos y relativos distintas subpoblaciones celulares de médula ósea normal y analizar la expresión de diferentes marcadores celulares específicos de linaje cuya reactividad está asociada a la diferenciación celular para ser usado como parte del control de calidad de rutina en los laboratorios de citometría. Materiales y métodos. El análisis inmunofenotípico de distintas subpoblaciones celulares se realizó en muestras de MO normal empleando un panel de anticuerpos monoclonales y policlonales útiles para la caracterización fenotípica de leucemias agudas en 4 fluorescencias distintas, con un protocolo que combina marcaje celular de antígenos de membrana y de citoplasma. El análisis de expresión se realizó en términos de intensidad media de fluorescencia. Para el cálculo de recuentos absolutos se adicionaron esferas fluorescentes de concentración conocida. Resultados. El panel de anticuerpos utilizado permitió la identificación y cuantificación de las distintas subpoblaciones leucocitarias normales de origen linfoide y mieloide incluyendo células precursoras CD34+, y poblaciones celulares más diferenciadas incluidas en las líneas granulocítica, monocítica y eritroide. Se establecieron los valores de referencia de las poblaciones celulares y los rangos de expresión de los diferentes marcadores celulares importantes como parte del control de calidad de rutina en los laboratorios de citometría. Conclusión. Los patrones inmunofenotípicos identificados y la determinación de los valores absolutos y relativos de referencia de las distintas poblaciones leucocitarias normales en MO podrán ser utilizados por los laboratorios de citometría como modelo para establecer parámetros de referencia en el análisis fenotípico de neoplasias hematológicas.
Objective. To describe a standardized flow cytometry protocol for the relative and absolute quantification of hematopoietic cell subpopulations from normal bone marrow, and to evaluate the expression of different lineage-specific cell markers with a reactivity associated to cell differentiation to be used as part of the routine quality control in cytometry laboratories. Materials and methods. The immunophenotypical analysis of different cell subpopulations was done with samples from normal bone marrow using a panel of monoclonal and polyclonal antibodies useful in the characterization of acute leukemias with four different fluorescences, by means of a protocol that combines cell labeling of membrane and cytoplasm antigens. Expression analysis was done in terms of mean fluorescence intensity (MFI). Fluorescent beads at a known concentration were added for calculating the absolute count of cells. Results. The antibody panel used allowed the identification and quantification of different normal leukocyte subpopulations of lymphatic and myeloid origin, including CD34+ stem cells and more differentiated cell populations in the granulocytic, monocytic, and erythroid cell lines. We established reference values for cell populations and cell marker expression ranges as part of routine quality control of cytometry laboratories. Conclusion. Immunophenotypic patterns identified as well as absolute and relative reference values for the different normal leukocyte populations from bone marrow can be used by cytometry laboratories as a basis for establishing reference parameters in phenotypic analyses of hematologic neoplasia.
Objetivo. Descrever um protocolo padronizado por citometria de fluxo para quantificar em termos absolutos e relativos diferentes subpopulações de células de medula óssea normal e analisar a expressão de diferentes marcadores celulares de linhagem específica, cuja reatividade é associada com a diferenciação celular para ser usado como parte do controle de qualidade de rotina nos laboratórios de citometria de fluxo. Materiais e métodos. A análise imunofenotípica das subpopulações de células foi realizada em amostras de MO normais utilizando um painel de anticorpos monoclonais e policlonais úteis para a caracterização fenotípica de leucemia aguda em quatro fluorescências, com um protocolo que combina rotulagem celular de antígeno de membrana celular e de citoplasma. A análise de expressão foi realizada em termos de intensidade média de fluorescência. Para calcular a recontagem absoluta foram adicionadas esferas fluorescentes de concentração conhecida. Resultados. O painel de anticorpos utilizado permitiu a identificação e quantificação das subpopulações de leucócitos normais de origem linfóide e mielóide incluindo as células precursoras CD34+, e populações de células mais diferenciadas incluídas nas linhas granulocítica, monocítica e eritróide. Foram estabelecidos os valores de referência das populações celulares e os intervalos de expressão dos diferentes marcadores celulares importantes como parte da rotina de controle de qualidade em laboratórios de citometria. Conclusão. Os padrões imunofenotípicos identificados e a determinação dos valores absolutos e relativos de referência das diferentes populações de leucócitos normais em MOM podem ser utilizados pelos laboratórios de citometria como um modelo para estabelecer parâmetros de referencia na análise fenotípica de neoplasias hematológicas.
ABSTRACT
PURPOSE: Multiparametric flow cytometry is a powerful tool for analyzing the phenotypic, cell kinetic and ploidy heterogeneity of tumor cell populations. But there are major problems such as inaccurate results by the contribution of non-neoplastic cell contamination and the substantial spectral overlap of PI (propidium iodide) into PE (phycoery- thrin) fluorescent emissions on a standard flow cytometer. Recent studies suggested that the emission spectral overlap from PI into PE could be sufficiently compensated electrically and the cytokeratin, a marker for epithelial tumor cells, are successfully used in conjunction with DNA specific dye so as to obtain DNA profiles selectively for cytokeratin-positive tumor cells. The aim of this study was to investigate the feasibility that multiparametric analysis in heterogeneous cell populations of cell lines like solid tumors, which were stained triply with PE, fluorescein isothiocyanate FITC, and PI, can be done without any influences by the contaminated normal diploid cell populations and without spectral overlap between fluorochromes on a standard flow cytometer. MATERIALS AND METHODS: MCF-7 cell lines and heterogeneous cell populations mixed with MCF-7 cells and human peripheral blood lymphocytes were fixed with 1% paraformal- dehyde and permeabilized with 100% methanol. Cytokeratin was labeled with PE and some proliferat!on-associated markers were labeled with FITC, which were followed by DNA staining by PI. These triply stained cells were measured on a standard FACScan flow cytometer equipped with 488 nm single laser and those acquired data were analyzed with WinList 3.0 and ModFit LT software programs on personal computor. RESULTS: Coefficient of variation (CV) of GoG1> peak of MCF-7 cells alone was 4.3. GoG1, S, and G2M phase fractions were 44.9%, 45.9%, and 9.2% respectively. FITC, PE and PI fluorochromes could be detected without any interference between them. CVs of GoG1 peak of PBL and MCF-7 cells in those heterogeneous population were 2.3 and 4.2 respectively. The DNA index of MCF-7 cells was 1.7. MCF-7 cells expressed the cyto- keratin, PCNA, p53, c-erbB/2 and c-myc antigen and in contrast, PBL did not express cytokeratin. The cell cycle phase fractions and oncoprotein expressions could be detected separately in diploid PBL and aneuploid MCF-7 cells in the mixed cell population without any influences by each other. CONCLUSION: These results suggested that the cellular antigen expressions of the malignant cells can be analyzed selectively without influences of fluorescent signals from nonneo- plastic cells. The neoplastic tumor subpopulations are clearly identified on the basis of both ploidy status and antigen expressions. The positive cytokeratin expressions indicate that they were derived from the epithelium, providing objective evidence of the tissue of origin and more precise analysis of DNA contents, ploidy, and oncogene expressions selectively with possible correlation between them. Thus, this method offers new possibilities for multiparameter flow cytometric analysis in the heterogeneous solid tumor cell populations.