Multiparametric Flow Cytometry versus Conventional Cytology in the Study of Leptomeningeal Involvement in Malignant Hematological Diseases.

BACKGROUND: CNS involvement is a complication in hematologic malignant neoplasms. The advantage of multiparametric flow cytometry (MFC) over conventional cytology (CC) in detecting occult leptomeningeal disease in CSF has been proven previously, as reported in the literature. In this study, we reviewed the experience of our laboratory in evaluating CSF specimens by MFC and CC after refinement of technical procedures. METHODS: MFC analysis was performed in 159 specimens. In 91 specimens, simultaneous CC and MFC analysis was requested and results compared. RESULTS: Neoplastic cells were identified in 27 (17.0%) of the total samples and in 17 (18.7%) of the paired specimens group by MFC, compared with 2 (2.2%) specimens with positive results as determined by CC. MFC enabled identification of malignant cells in low-cellularity specimens (<5 cells/µL) and all neoplasm categories. CONCLUSION: MFC allowed the detection of minimal numbers of tumor cells in CSF specimens from individuals with leukemia and lymphoma in whom CC had not been able to identify those tumor cells.

Evaluation of CD307a expression patterns during normal B-cell maturation and in B-cell malignancies by flow cytometry.

BACKGROUND: Flow cytometric immunophenotyping is deemed a fundamental tool for the diagnosis of B-cell neoplasms. Currently, the investigation of novel immunophenotypic markers has gained importance, as they can assist in the precise subclassification of B-cell malignancies by flow cytometry. Therefore, the purpose of the present study was to evaluate the expression of CD307a during normal B-cell maturation and in B-cell malignancies as well as to investigate its potential role in the differential diagnosis of these entities. METHODS: CD307a expression was assessed by flow cytometry in normal precursor and mature B cells and in 115 samples collected from patients diagnosed with precursor and mature B-cell neoplasms. CD307a expression was compared between neoplastic and normal B cells. RESULTS: B-acute lymphoblastic leukemia cases exhibited minimal expression of CD307a, displaying a similar expression pattern to that of normal B-cell precursors. Mantle cell lymphoma (MCL) cases showed the lowest levels of CD307a among mature B-cell neoplasms. CD307a expression was statistically lower in MCL cases than in chronic B lymphocytic leukemia (CLL) and marginal zone lymphoma (MZL) cases. No statistical differences were observed between CD307a expression in neoplastic and normal plasma cells. CONCLUSION: These results indicate that the assessment of CD307a expression by flow cytometry could be helpful to distinguish CLL from MCL, and the latter from MZL. Although these results are not entirely conclusive, they provide a basis for further studies in a larger cohort of patients. © 2018 International Clinical Cytometry Society.

Determination of normal expression patterns of CD86, CD210a, CD261, CD262, CD264, CD358, and CD361 in peripheral blood and bone marrow cells by flow cytometry.

In 2010, new monoclonal antibodies were submitted to the 9th International Workshop on Human Leukocyte Differentiation Antigens, and there are few studies demonstrating normal expression patterns of these markers. Thus, the objective of this study was to determine the normal patterns of cell expression of CD86, CD210a, CD261, CD262, CD264, CD358, and CD361 in peripheral blood (PB) and bone marrow (BM) samples by flow cytometry. In the present study, CD86 was expressed only in monocytes and B lymphocytes in PB and in monocytes and plasma cells in BM. Regarding CD210a expression, in PB samples, monocytes and NK cells showed weak expression, while neutrophils, B and T lymphocytes, and basophils showed weak and partial expression. In BM samples, expression of CD210a was observed in eosinophils, monocytes, and B and T/NK lymphocytes. Weak expression of CD210a was also observed in neutrophilic cells and plasma cells. All B cell maturation stages had weak expression of CD210a except for immature B cells, which did not express this marker. In the present study, no cell type in PB samples showed positivity for CD261 and, in BM samples, there was very weak expression in neutrophilic series, monocytes, and B lymphocytes. Conversely, plasma cells showed positivity for CD261 with a homogeneous expression. For CD262, there was weak expression in monocytes, neutrophils, and B lymphocytes in PB samples and weak expression in monocytes, B lymphocytes, and plasma cells in BM samples. The evaluation of CD264 showed very weak expression in B cells in PB samples and no expression in BM cells. Very weak expression of CD358 was observed in neutrophils, monocytes, and B lymphocytes in PB and BM samples. In addition, in BM samples, plasma cells and T lymphocytes showed weak expression of CD358. In relation to the maturation stages of B cells, there was weak expression in pro-B cel, pre-B cell, and mature B cell. In the present study, it was possible to observe expression of CD361 in all cell types analyzed in PB and BM samples. The analyzed markers presented varied profiles of expression and, in some cases, these profiles were different from those observed in other studies. Further studies are needed to evaluate these molecules, mainly in relation to a possible application in the diagnosis of hematological malignancies or as new therapeutic targets for the treatment of hematological neoplasms or autoimmune diseases.

The importance of CD39, CD43, CD81, and CD95 expression for differentiating B cell lymphoma by flow cytometry.

BACKGROUND: B cell lymphomas' (BCL) current diagnosis is usually based on a combination of morphology, immunophenotype, recurrent cytogenetic aberration and clinical features. However, even with these diagnostic tools, a definitive diagnosis can be difficult to achieve. Therefore, the aim of this study was to assess the profile of CD39, CD43, CD81, and CD95 expressions in diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and Burkitt lymphoma (BL) cases. METHODS: To address this issue, we investigated the expression of CD39, CD43, CD81, and CD95 by eight-color flow cytometry in retrospective cases from 2014 to 2016. RESULTS: The study included 27 adult patients diagnosed with DLBCL, FL, and BL during the study period. Four patients were diagnosed with germinal center B cell-like DLBCL (GCB DLBCL), seven with non-GCB DLBCL, nine with FL, and seven with BL. CD39 seems to be especially relevant to differentiate non-GCB DLBCL from BL and from FL. BL showed stronger expression of CD43 when compared to FL and GCB DLBCL. Moreover, CD43 may help to distinguish non-GCB DLBCL from GCB DLBCL. CD81 expression was much stronger in BL when compared to the other three groups of patients. Lastly, CD95 may also help to distinguish BL from the other subtypes, as BL cells expressed this antigen at low levels. CONCLUSIONS: In combination, CD39, CD43, CD81, and CD95 expressions appear to be helpful to distinguish CD10+ BCL, particularly BL. Phenotypic distinction between FL and GCB DLBCL remains challenging and requires further studies. © 2017 International Clinical Cytometry Society.