644 research outputs found
Immunophenotypic characterization of normal blood CD56+lo versus CD56+hi NK‐cell subsets and its impact on the understanding of their tissue distribution and functional properties
Blood Cells Mol Dis. 2001 Jul-Aug;27(4):731-43.
Immunophenotypic characterization of normal blood CD56+lo versus CD56+hi NK-cell subsets and its impact on the understanding of their tissue distribution and functional properties.
Lima M, Teixeira MA, Queirós ML, Leite M, Santos AH, Justiça B, Orfão A.
Service of Clinical Hematology, Unit of Cytometry, Hospital Geral de Santo António, Porto, Portugal. [email protected]
Abstract
In the present study we have compared the immunophenotypic characteristics of the CD56+lo and CD56+hi NK-cell subsets in a group of normal healthy adults. Our results show that CD56+hi NK-cells display greater light-scatter properties than CD56+lo NK-cells at the same time they have higher levels of CD25 and CD122 IL-2 chains, together with a higher reactivity for HLA-DR and CD45RO and lower levels of CD45RA, supporting that, as opposed to the majority of the CD56+lo population, CD56+hi NK-cells might correspond to a subset of activated circulating NK-lymphocytes. Higher expression of the CD2 and CD7 costimulatory molecules found for the CD56+hi NK-cells would support their greater ability to respond to various stimuli. In addition, CD56+hi NK-cells expressed higher levels of several adhesion molecules such as CD2, CD11c, CD44, CD56, and CD62L compared to CD56+lo NK-cells, supporting a particular ability of these cells to migrate from blood to tissues and/or a potential advantage to form conjugates with target cells. Interestingly, CD56+lo and CD56+hi NK-cells showed a different pattern of expression of killer receptors that might determine different activation requirements for each of these NK-cell subsets. For instance, absence or low levels of CD16 expression might explain the lower antibody-dependent cytotoxicity activity of CD56+hi NK-cells. On the other hand, the virtual absence of expression of the CD158a and NKB1 immunoglobulin-like and the greater reactivity for the CD94 lectin-like killer receptors on CD56+hi in comparison to CD56+lo NK-cells might determine different MHC-class I specificities for both NK-cell subsets, a possibility that deserves further studies to be confirmed.
PMID: 11778657 [PubMed - indexed for MEDLINE
An unusual acute myeloid leukemia associated with hyper IgE: another case of AML‐M5c?
Haematologica. 2001 Feb;86(2):216-7.
An unusual acute myeloid leukemia associated with hyper IgE: another case of AML-M5c?
Lima M, Orfão A, Coutinho J, Ferreira G, Freitas I, Silvestre F, Justiça B.
PMID: 11224498 [PubMed - indexed for MEDLINE
Discrimination of biclonal B-cell chronic lymphoproliferative neoplasias by tetraspanin antigen expression
This work was supported by Grants from MEC SAF2004-02900 (PAL) and SAF 2002-03096 (AO), Fondo de Investigación Sanitaria PI02-0585 (PAL), and Fundación Memoria Samuel Solórzano Barruso (PAL).Peer Reviewe
Intraclonal diversity in a Sezary syndrome with a differential response to 2‐deoxycoformycin of the two lymphoma cell populations
Br J Haematol. 2002 Dec;119(3):629-33.
Intraclonal diversity in a Sezary syndrome with a differential response to 2-deoxycoformycin of the two lymphoma cell populations.
Granjo E, Lima M, Lopes JM, Cunha N, Teixeira Mdos A, Santos F, Candeias J, Resende C, Santos AH, Balanzategui A, Orfão A, Matutes E.
Department of Clinical Haematology, Hospital Geral de São João, Porto, Portugal. [email protected]
Abstract
We report a case of Sezary syndrome with two abnormal CD4+ T-cell populations detected in the peripheral blood by flow cytometry immunophenotyping and DNA cell content, suggesting a biclonal T-cell lymphoproliferative disorder. Despite these findings, molecular analysis of the T-cell receptor genes was consistent with a monoclonal T-cell proliferation, supporting the existence of intraclonal diversity rather than a true biclonal disease. The patient achieved a transient response with 2-deoxycoformycin, with a selective decrease of the larger/hyperploid T-cell population; later on, an increased representation of this T-cell population was observed concomitantly with clinical relapse.
PMID: 12437636 [PubMed - indexed for MEDLINE
Reactive phenotypes after acute and chronic NK‐cell activation
J Biol Regul Homeost Agents. 2004 Jul-Dec;18(3-4):331-4.
Reactive phenotypes after acute and chronic NK-cell activation.
Lima M, Almeida J, Teixeira MA, Santos AH, Queirós ML, Fonseca S, Moura J, Gonçalves M, Orfão A, Pinto Ribeiro AC.
Service of Clinical Hematology, Laboratory of Cytometry, Hospital Geral de Santo António, Porto, Portugal. [email protected]
Abstract
Several phenotypic changes have been shown to occur after NK-cell stimulation, involving molecules that have been proved to regulate NK-cell migration into tissues and NK-cell activation and proliferation as well as target cell recognition and killing. Here, we review the reactive phenotypes observed in vivo after acute and chronic NK-cell activation.
PMID: 15786700 [PubMed - indexed for MEDLINE
Immunophenotype and TCR‐Vbeta repertoire of peripheral blood T‐cells in acute infectious mononucleosis.
Blood Cells Mol Dis. 2003 Jan-Feb;30(1):1-12.
Immunophenotype and TCR-Vbeta repertoire of peripheral blood T-cells in acute infectious mononucleosis.
Lima M, Teixeira Mdos A, Queirós ML, Santos AH, Gonçalves C, Correia J, Farinha F, Mendonça F, Soares JM, Almeida J, Orfão A, Justiça B.
Service of Clinical Haematology, Hospital Santo António, Porto, Portugal. [email protected]
Abstract
Although a number of studies on the phenotypic changes that occur after T-cell activation have already been published, the specific immunophenotypic features of T-lymphocytes and the frequency at which TCR-variable region (TCR-V) restricted T-cell expansions occur "in vivo" during acute viral infection still remains to be established. We report on the immunophenotype and TCR-V repertoire of peripheral blood T-cells from 28 patients with acute infectious mononucleosis. Immunophenotypic studies were performed by flow cytometry using direct immunofluorescence techniques and stain-and-then-lyse sample preparation protocols with three- and four-colour combinations of monoclonal antibodies directed against a large panel of T- and NK-cell associated markers, activation- and adhesion-related molecules and TCR-Vbeta, -Vgamma and -Vdelta families. Nearly all patients (27/28) showed a massive expansion of CD8(+)/TCRalphabeta(+) T cells, the majority (>90%) of which displayed an immunophenotype compatible with T-cell activation: CD2(+high), CD7(+low), CD11a(+high), CD38(+high), HLA-DR(+high), CD28(+/-low), CD45RO(+high), CD45RA(-/+low), CD11b(-/+low), CD11c(+/-low), CD16(-), CD56(-), CD57(-), CD62L(-), CD94(-), CD158a(-), CD161(-), NKB1(-). Additionally, the levels of both CD3 and CD5 were slightly decreased compared to those found in normal individuals. Late-activation antigens, such as CD57, were found in small proportions of CD8(+)/TCRalphabeta(+) T-cells. Increased numbers of CD4(+)/TCRalphabeta(+) T-cells, TCRgammadelta(+) T-cells and NK-cells were also noticed in 17, 16 and 13 of the 28 cases studied, respectively. Evidence for activation of CD4(+)/TCRalphabeta(+) and TCRgammadelta(+) T-cells relied on changes similar to those described for CD8(+)/TCRalphabeta(+) although less pronounced, except for higher levels of both CD5 and CD28 in the absence of reactivity for CD11c on CD4(+)/TCRalphabeta(+) T-cells and higher levels of CD161 and CD94 on TCRgammadelta(+) T-cells. Small expansions of one or more TCR-Vbeta families accounting for 12 +/- 7% of either the CD8(+)/TCRalphabeta(+) or the CD4(+)/TCRalphabeta(+) T-cell compartment were found in 12 of 14 patients studied, whereas the distribution of the TCR-Vgamma and -Vdelta repertoires tested in 2 of the individuals with expanded TCRgammadelta(+) T-cells was similar to that observed in control individuals. The results presented here provide evidence for an extensive T-cell activation during acute viral infection and establish the immunophenotype patterns associated with this condition.
PMID: 12667982 [PubMed - indexed for MEDLINE
Molecular and cytogenetic characterization of expanded B-cell clones from multiclonal versus monoclonal B-cell chronic lymphoproliferative disorders
Chronic antigen-stimulation has been recurrently involved in the earlier stages of monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The expansion of two or more B-cell clones has frequently been reported in individuals with these conditions; potentially, such coexisting clones have a greater probability of interaction with common immunological determinants. Here, we analyzed the B-cell receptor repertoire and molecular profile, as well as the phenotypic, cytogenetic and hematologic features, of 228 chronic lymphocytic leukemia-like and non-chronic lymphocytic leukemia-like clones comparing multiclonal (n=85 clones from 41 cases) versus monoclonal (n=143 clones) monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The B-cell receptor of B-cell clones from multiclonal cases showed a slightly higher degree of HCDR3 homology than B-cell clones from mono clonal cases, in association with unique hematologic (e.g. lower B-lymphocyte counts) and cytogenetic (e.g. lower frequency of cytogenetically altered clones) features usually related to earlier stages of the disease. Moreover, a subgroup of coexisting B-cell clones from individual multiclonal cases which were found to be phylogenetically related showed unique molecular and cytogenetic features: they more frequently shared IGHV3 gene usage, shorter HCDR3 sequences with a greater proportion of IGHV mutations and del(13q14.3), than other unrelated B-cell clones. These results would support the antigen-driven nature of such multiclonal B-cell expansions, with potential involvement of multiple antigens/epitopes
MRD detection in multiple myeloma: comparison between MSKCC 10-color single-tube and EuroFlow 8-color 2-tube methods
[EN] In patients with multiple myeloma, obtaining posttreatment minimal residual disease (MRD) negativity is associated with longer progression-free survival and overall survival. Here, we compared the diagnostic performance of a single 10-color tube with that of a EuroFlow 8-color 2-tube panel for MRD testing. Bone marrow samples from 41 multiple myeloma patients were tested in parallel using the 2 approaches. Compared with the sum of the cells from the EuroFlow two 8-color tubes, the Memorial Sloan Kettering Cancer Center (MSKCC) single 10-color tube had a slight reduction in total cell number with a mean ratio of 0.85 (range, 0.57-1.46; P < .05), likely attributable to permeabilization of the cells. Percent of plasma cells showed a high degree of concordance (r2 = 0.97) as did normal plasma cells (r2 = 0.96), consistent with no selective plasma cell loss. Importantly, concordant measurement of residual disease burden was seen with abnormal plasma cells (r2 = 0.97). The overall concordance between the 2 tests was 98%. In 1 case, there was a discrepancy near the limit of detection of both tests in favor of the slightly greater theoretical sensitivity of the EuroFlow 8-color 2-tube panel (analytical sensitivity limit of MSKCC single 10-color tube: 6 cells in 1 million with at least 3 million cell acquisitions; EuroFlow 8-color 2-tube panel: 2 cells in 1 million with the recommended 10 million cell acquisitions)
Phenotypic profile of expanded NK cells in chronic lymphoproliferative disorders: a surrogate marker for NK-cell clonality
Currently, the lack of a universal and specific marker of clonality hampers the diagnosis and classification of chronic expansions of natural killer (NK) cells. Here we investigated the utility of flow cytometric detection of aberrant/altered NK-cell phenotypes as a surrogate marker for clonality, in the diagnostic work-up of chronic lymphoproliferative disorders of NK cells (CLPD-NK). For this purpose, a large panel of markers was evaluated by multiparametric flow cytometry on peripheral blood (PB) CD56low NK cells from 60 patients, including 23 subjects with predefined clonal (n = 9) and polyclonal (n = 14) CD56low NK-cell expansions, and 37 with CLPD-NK of undetermined clonality; also, PB samples from 10 healthy adults were included. Clonality was established using the human androgen receptor (HUMARA) assay. Clonal NK cells were found to show decreased expression of CD7, CD11b and CD38, and higher CD2, CD94 and HLADR levels vs. normal NK cells, together with a restricted repertoire of expression of the CD158a, CD158b and CD161 killer-associated receptors. In turn, NK cells from both clonal and polyclonal CLPD-NK showed similar/overlapping phenotypic profiles, except for high and more homogeneous expression of CD94 and HLADR, which was restricted to clonal CLPD-NK. We conclude that the CD94hi/HLADR+ phenotypic profile proved to be a useful surrogate marker for NK-cell clonality
Impact of blood storage and sample handling on quality of high dimensional flow cytometric data in multicenter clinical research
Obtaining reliable and reproducible high quality data in multicenter clinical research settings requires design of optimal standard operating procedures. While the need for standardization in sample processing and data analysis is well-recognized, the impact of sample handling in the pre-analytical phase remains underestimated. We evaluated the impact of sample storage time (approximate to transport time) and temperature, type of anticoagulant, and limited blood volume on reproducibility of flow cytometric studies.
EDTA and Na-Heparin samples processed with the EuroFlow bulk lysis protocol, stained and stored at 4 degrees C showed fairly stable expression of cell surface markers and distribution of the major leukocyte populations for up to 72 h. Additional sample fixation (1% PFA, Fix & Perm) did not have any beneficial effects. Blood samples stored for < 24 h at room temperature before processing and staining seemed suitable for reliable immunophenotyping, although losses in absolute cell numbers were observed. The major losses were observed in myeloid cells and monocytes, while lymphocytes seemed less affected. Expression of cell surface markers and population distribution were more stable in Na-Heparin blood than in EDTA blood. However, storage of Na-Heparin samples was associated with faster decrease in leukocyte counts over time. Whole blood fixation strategies (Cyto-Chex, TransFix) improved long-term population distribution, but were detrimental for expression of cellular markers. The main conclusions from this study on healthy donor blood samples were successfully confirmed in EDTA clinical (patient) blood samples with different time delays until processing. Finally, we recognized the need for adjustments in bulk lysis in case of insufficient blood volumes.
Despite clear overall conclusions, individual markers and cell populations had different preferred conditions. Therefore, specific guidelines for sample handling should always be adjusted to the clinical application and the main target leukocyte population
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