ABSTRACT
SUMMARY OBJECTIVE: Ki-67 is a nuclear protein associated with cellular proliferation in normal or leukemic conditions that can help identify more aggressive diseases and is usually evaluated with immunohistochemistry. The aim of this was to assess Ki-67 expression on mature B-cell neoplasms samples with flow cytometry immunophenotyping. METHOD: After surface staining with CD19 and CD45, intracellular staining for Ki-67 was performed in leukemic mature B-cells. Ki-67 expression was evaluated with flow cytometry. RESULTS: Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma, and diffuse large B-cell lymphoma cases. It was also associated with CD38 mean fluorescence intensity. CONCLUSIONS: Ki-67 expression evaluated by flow cytometry can be a useful tool in the diagnosis of mature B-cell neoplasms. More studies are needed to validate Ki-67 assessment with flow cytometry immunophenotyping.
RESUMO OBJETIVO: Ki-67 é uma proteína nuclear associada à proliferação celular em condições normais ou leucêmicas que pode ajudar a Identificar doenças mais agressivas. Este marcador é geralmente avaliado com imuno-histoquímica. O objetivo deste estudo foi avaliar a expressão de Ki-67 em amostras de neoplasias de células B maduras com imunofenotipagem por citometria de fluxo. MÉTODO: Após marcação de superfície com CD19 e CD45, foi realizada marcação intracelular para Ki-67 em células B maduras leucémicas. A expressão de Ki-67 foi avaliada por citometria de fluxo. RESULTADOS: A expressão de Ki-67 foi maior em células de linfomas de manto, linfoma de Burkitt e linfoma difuso de grandes células B. Também houve associação de Ki-67 à intensidade de fluorescência média de CD38. CONCLUSÃO: A expressão de Ki-67 avaliada por citometria de fluxo pode ser útil no diagnóstico de neoplasias de células B maduras. São necessários mais estudos para validar a avaliação de Ki-67 com Imunofenotipagem por citometria de fluxo.
Subject(s)
Humans , B-Lymphocytes/metabolism , Leukemia, B-Cell/metabolism , Ki-67 Antigen/metabolism , Immunophenotyping/methods , Antigens, CD19 , Lymphoma, Mantle-Cell/metabolism , Flow Cytometry/methodsABSTRACT
We evaluated the expression of 10 adhesion molecules on peripheral blood tumor cells of 17 patients with chronic lymphocytic leukemia, 17 with mantle-cell lymphoma, and 13 with nodal or splenic marginal B-cell lymphoma, all in the leukemic phase and before the beginning of any therapy. The diagnosis of B-cell non-Hodgkin's lymphomas was based on cytological, histological, immunophenotypic, and molecular biology methods. The mean fluorescence intensity of the adhesion molecules in tumor cells was measured by flow cytometry of CD19-positive cells and differed amongst the types of lymphomas. Comparison of chronic lymphocytic leukemia and mantle-cell lymphoma showed that the former presented a higher expression of CD11c and CD49c, and a lower expression of CD11b and CD49d adhesion molecules. Comparison of chronic lymphocytic leukemia and marginal B-cell lymphoma showed that the former presented a higher expression of CD49c and a lower expression of CD11a, CD11b, CD18, CD49d, CD29, and CD54. Finally, comparison of mantle-cell lymphoma and marginal B-cell lymphoma showed that marginal B-cell lymphoma had a higher expression of CD11a, CD11c, CD18, CD29, and CD54. Thus, the CD49c/CD49d pair consistently demonstrated a distinct pattern of expression in chronic lymphocytic leukemia compared with mantle-cell lymphoma and marginal B-cell lymphoma, which could be helpful for the differential diagnosis. Moreover, the distinct profiles of adhesion molecules in these diseases may be responsible for their different capacities to invade the blood stream.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged, 80 and over , Cell Adhesion Molecules/biosynthesis , Leukocytes, Mononuclear/metabolism , Lymphoma, B-Cell/metabolism , Diagnosis, Differential , Flow Cytometry , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Lymphoma, Mantle-Cell/metabolism , Lymphoma, B-Cell, Marginal Zone/metabolism , Biomarkers, Tumor/blood , Biomarkers, Tumor/metabolismABSTRACT
The differential diagnosis of certain B CD5+ lymphoproliferative processes, such as mantle cell lymphoma (MCL) and atypical chronic lymphocytic leukemia (ACLL), is difficult. The aim of this study was to correlate morphological findings, cyclin D1 (cD1) detection by immunohistochemistry (IHC) and immunophenotype by flow cytometry (FC) with the results obtained by molecular biology in this type of neoplasias. We analyzed 20 samples classified as B CD5+ lymphoproliferative processes by FC. PCR was used for t(11;14) bcl-1/IgH determination. Histopathological and IHC studies for cD1 were done in 14 cases. Twelve cases were diagnosed as MCL, with positive cD1 in 5 (5/9), five as ACLL and three as B lymphoproliferative process. PCR revealed t(11;14) in 6/12 MCL and negative results in the other groups (0/8). Molecular biology evidenced translocation in 4/5 MCL positive for cD1 with IHC. The presence of translocation could be demonstrated by IHC and PCR in 7/12 MCL: 4 with both techniques, 2 with PCR alone, and 1 with IHC alone. These findings show a significant association between cD1 by IHC and bcl-1/ IgH gene detection by PCR, which implies that both techniques are complementary for MCL typing.
Algunos procesos linfoproliferativos B CD5+ son de difícil diagnóstico diferencial como es el casodel linfoma del manto (LM) y la leucemia linfocítica crónica atípica (LLCA). El motivo del presenteestudio fue correlacionar los hallazgos morfológicos, la detección de ciclina D1 (cD1) por inmunohistoquímica(IHQ) y el inmunofenotipo por citometría de flujo (CF) con los resultados obtenidos por biología molecular en este tipo de neoplasias. Se estudiaron 20 muestras clasificadas como procesos linfoproliferativos B CD5+ por CF. Se realizó la determinación de t(11;14) bcl-1/IgH por PCR. El estudio histopatológico e IHQ para cD1 se efectuó en 14 casos. Doce casos fueron diagnosticados como LM, con cD1 positiva en 5 (5/9); cinco como LLCA y tres como proceso linfoproliferativo B. Con PCR se observó t(11;14) en 6/12 LM y negatividad en losrestantes grupos (0/8). Se pudo demostrar la presencia de traslocación en 7/12 LM mediante IHQ Y PCR: 4con ambas técnicas, 2 con PCR exclusivamente y 1 con IHQ, evidenciando una alta asociación entre cD1 por IHQ y la detección del gen bcl-1/IgH por PCR, ambas técnicas complementarias en la tipificación de LM.