Publications (23)104.4 Total impact
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Article: Combined flow cytometric assessment of CD45, HLA-DR, CD34, and CD117 expression is a useful approach for reliable quantification of blast cells in myelodysplastic syndromes.
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ABSTRACT: BACKGROUND.: Quantification of bone marrow (BM) blasts by cytomorphology is essential for the diagnosis of myelodysplastic syndromes (MDS). Owing to its subjectivity and the potential impact of dysplastic features on accurate identification of blast cells, more objective approaches are required, multiparameter flow cytometry (MFC) being a particularly promising approach in this regard. However, no consensus exists about the optimal combination of markers and strategy to be used. METHODS.: BM blast counts from 74 MDS patients were evaluated by morphology versus four different MFC phenotypic criteria: "CD34+ ", "CD34+ and/or CD117+ ", "CD34+ , and/or CD117+ HLA-DR+ ", and "CD34+ and CD117+ HLA-DR+ plus CD64+ CD14-/lo " cells. For each criterium, the percentage of blasts was calculated using either all BM nucleated cells or non-erythroid CD45+ cells as denominator. RESULTS.: The number of "CD34+ and/or CD117+ HLA-DR+ "cells showed the highest correlation and agreement with morphological counts, only a minor proportion of cases being misclassified by MFC vs. morphology for the >5% and >10% classification thresholds. In turn, a CD34+ phenotype was insufficient to correctly identify and quantify blasts. Conversely, usage of non-erythroid BM cells as denominator, or inclusion of "CD34+ and/or CD117+ HLA-DR+ plus CD64+ CD14-lo" cells were both associated with overestimated blast counts. CONCLUSIONS.: Quantification of "CD34+ and/or CD117+ HLA-DR+ " cells (from all nucleated BM cells) by MFC is an efficient method for the enumeration of blasts in MDS. However, caution should be taken with replacing morphology by MFC blast counts; its combined use may rather provide complementary information increasing the accuracy and reproducibility of BM blast cell counts in these patients. © 2013 International Clinical Cytometry Society.Cytometry Part B Clinical Cytometry 03/2013; · 2.53 Impact Factor -
Article: Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.
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ABSTRACT: Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.Little is known about the distribution of normal lymphoid cells and their subsets in the peripheral blood (PB) of subjects with monoclonal B-cell lymphocytosis (MBL). In our study, we compared the absolute number of PB lymphoid cells and their subpopulations in 95 MBL cases with normal lymphocyte counts vs. 617 age-/sex-matched non-MBL healthy subjects (controls), using highly sensitive flow cytometry. MBL cases showed significantly reduced numbers of normal circulating B-cells, at the expense of immature and naive B-cells; in addition, CD4+CD8+ double-positive T-cells and CD8+ T-cells were significantly lower and higher vs. controls, respectively. Moreover, most normal B-cell subsets were significantly decreased in PB at >1% MBL-counts, vs. "low-count" MBL cases, and lower amounts of immature/naive B-cells were detected in biclonal (particularly in cases with coexisting CLL-like- and non-CLL-like B-cell clones) vs. monoclonal MBL subjects. In summary, our results show imbalanced (reduced) absolute numbers of recently produced normal circulating B-cells (e.g., immature and naıve B-cells) in MBL, which becomes more pronounced as the MBL cell count increases.American Journal of Hematology 03/2012; 87(7):721-4. · 4.67 Impact Factor -
Article: The proliferation index of specific bone marrow cell compartments from myelodysplastic syndromes is associated with the diagnostic and patient outcome.
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ABSTRACT: Myelodysplastic syndromes (MDS) are clonal stem cell disorders which frequently show a hypercellular dysplastic bone marrow (BM) associated with inefficient hematopoiesis and peripheral cytopenias due to increased apoptosis and maturation blockades. Currently, little is known about the role of cell proliferation in compensating for the BM failure syndrome and in determining patient outcome. Here, we analyzed the proliferation index (PI) of different compartments of BM hematopoietic cells in 106 MDS patients compared to both normal/reactive BM (n = 94) and acute myeloid leukemia (AML; n = 30 cases) using multiparameter flow cytometry. Our results show abnormally increased overall BM proliferation profiles in MDS which significantly differ between early/low-risk and advanced/high-risk cases. Early/low-risk patients showed increased proliferation of non-lymphoid CD34(+) precursors, maturing neutrophils and nucleated red blood cells (NRBC), while the PI of these compartments of BM precursors progressively fell below normal values towards AML levels in advanced/high-risk MDS. Decreased proliferation of non-lymphoid CD34(+) and NRBC precursors was significantly associated with adverse disease features, shorter overall survival (OS) and transformation to AML, both in the whole series and when low- and high-risk MDS patients were separately considered, the PI of NRBC emerging as the most powerful independent predictor for OS and progression to AML. In conclusion, assessment of the PI of NRBC, and potentially also of other compartments of BM precursors (e.g.: myeloid CD34(+) HPC), could significantly contribute to a better management of MDS.PLoS ONE 01/2012; 7(8):e44321. · 4.09 Impact Factor -
Article: Pedestrian navigation based on a waist-worn inertial sensor.
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ABSTRACT: We present a waist-worn personal navigation system based on inertial measurement units. The device makes use of the human bipedal pattern to reduce position errors. We describe improved algorithms, based on detailed description of the heel strike biomechanics and its translation to accelerations of the body waist to estimate the periods of zero velocity, the step length, and the heading estimation. The experimental results show that we are able to support pedestrian navigation with the high-resolution positioning required for most applications.Sensors 01/2012; 12(8):10536-49. · 1.74 Impact Factor -
Article: Cell-cycle distribution of different cell compartments in normal versus reactive bone marrow: a frame of reference for the study of dysplastic hematopoiesis.
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ABSTRACT: Limited information is currently available about the proliferation activity and cell-cycle distribution of different bone marrow (BM) cell subsets defined according to their lineage and maturation stage in normal versus cytopenia-associated reactive BM samples. Here, we report a three-color flow cytometry approach to investigate the cell-cycle distribution of different BM cell compartments-CD34(+) hematopoietic progenitor and precursor cells (HPC), maturing neutrophils and monocytic cells, mature lymphocytes, eosinophils, and nucleated red blood cell precursors (NRBC)-from normal (n = 47) versus cytopenia-associated reactive (n = 47) BM samples. Highly similar proliferation profiles were detected in normal versus reactive BM, with a higher proliferation index (PI) for the more immature CD34(+) HPC, CD11b(-) maturing neutrophils and NRBC versus other BM cell compartments. The only differences observed between normal and reactive BM were restricted to the more mature (CD13(hi) /CD11b(+) ) bands/neutrophils and to monocytic cells, which showed an increased PI (0.9% ± 0.8% vs. 0.6% ± 0.5% and 6 ± 3.6 vs. 4.6 ± 4.5, respectively) at the expense of a lower PI of CD34(+) HPC in reactive conditions. Of note, bands/mature neutrophils and mature lymphocytes showed either residual numbers or absence of S + G₂ /M-phase cells in both normal and reactive BM. Our results suggest that a slight shift of proliferation from the early precursors to the more mature granulomonocytic compartment occurs in reactive BM, which could reflect an attempt of the hematopoietic system to rapidly produce functional neutrophils and monocytes, at the expense of a lower expansion of the minor compartments of CD34(+) HPC.Cytometry Part B Clinical Cytometry 06/2011; 80(6):354-61. · 2.53 Impact Factor -
Article: Flow cytometry immunophenotyping of fine-needle aspiration specimens: utility in the diagnosis and classification of non-Hodgkin lymphomas.
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ABSTRACT: To establish the utility of flow cytometry (FCM) for screening and diagnosis of B cell non-Hodgkin lymphoma (B-NHL) from lymphoid tissue samples obtained by fine-needle aspiration (FNA). We compared prospectively FCM versus cytology/histology analysis of FNA samples for the diagnostic screening and further World Health Organization (WHO) subclassification of B-NHL. FCM and cytology showed a high degree of agreement (93%); however, diagnosis of reactive processes (RP), B-NHL and T-NHL by FCM showed higher sensitivity than cytology (92-100% versus 64-94%, respectively), without false positive NHL cases. The antibody combination used did not allow a positive diagnosis of Hodgkin lymphoma as distinct from a RP. A high concordance rate was found between FCM and histopathology (74%) in subtyping B-NHL. In this regard, mantle-cell lymphoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma showed the highest degree of agreement (100% concordant rates). In turn, FCM showed higher sensitivity/specificity in classifying follicular lymphoma (FL) and large B cell lymphomas, while the opposite occurred for marginal-zone and lymphoplasmacytic lymphomas. FCM enhances the diagnostic ability of FNA cytology, playing a crucial role in a rapid and accurate differential diagnosis between RP, B-NHL and T-NHL. In addition, immunophenotyping of FNA samples contributes to a more precise subclassification of B-NHL when combined with histopathology and genetic/molecular data.Histopathology 03/2011; 58(6):906-18. · 3.08 Impact Factor -
Article: Bone marrow cells from myelodysplastic syndromes show altered immunophenotypic profiles that may contribute to the diagnosis and prognostic stratification of the disease: a pilot study on a series of 56 patients.
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ABSTRACT: A heterogeneous spectrum of immunophenotypic abnormalities have been reported in myelodysplastic syndromes (MDS). However, most studies are restricted to the analysis of CD34(+) cells and/or other major subsets of CD34(-) cells, frequently not exploring the diagnostic and prognostic impact of immunophenotyping. We propose for the first time an immunophenotypic score (IS) based on the altered distribution and immunophenotypic features of maturing/mature compartments of bone marrow (BM) hematopoietic cells in 56 patients with MDS that could contribute to a refined diagnosis and prognostic evaluation of the disease. Although MDS-associated phenotypes were detected in reactive BM, the overall immunophenotypic profile of BM cells allowed an efficient discrimination between MDS and both normal and reactive BM, once the number and degree of severity of the abnormalities detected per patient were simultaneously considered in the proposed IS. Interestingly, increasingly higher IS were found among patients with MDS showing adverse prognostic factors and in low- versus high-grade cases. The most informative prognostic factors included the number of CD34(+) cells, presence of aberrant CD34(-)/CD117(+) precursors, decreased mature neutrophils and CD34(-) erythroid precursors, and increased numbers of CD36(-/lo) erythroid precursors; in addition, the IS was an independent prognostic factor for overall survival. Assessment of immunophenotypic abnormalities of maturing/mature BM cells allows an efficient discrimination between MDS and both normal and reactive BM, once the number and degree of severity of the abnormalities detected are simultaneously scored. Interestingly, progressively higher IS were found among patients with MDS with adverse prognostic features and shorter overall survival.Cytometry Part B Clinical Cytometry 03/2010; 78(3):154-68. · 2.53 Impact Factor -
Article: Utility of flow cytometry immunophenotyping in multiple myeloma and other clonal plasma cell-related disorders.
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ABSTRACT: In recent years, multiparameter flow cytometry (MFC) immunophenotyping has become mandatory in the clinical management of hematological malignancies, both for diagnostic and monitoring purposes. Multiple myeloma (MM) and other clonal plasma cell-related (PC) disorders should be no exception to this paradigm, but incorporation of immunophenotypic studies in the management of patients with PC disorders is still far from being routinely established in many diagnostic flow cytometry laboratories. For clonal PC disorders, MFC is of clear and established clinical relevance in: (1) the differential diagnosis between MM and other PC-related disorders; (2) the identification of high-risk MGUS and smoldering MM; (3) minimal residual disease investigation after therapy; additionally it may also be useful for (4) the definition of prognosis-associated antigenic profiles; and (5) the identification of new therapeutic targets. In this article, we review the clinical value of MFC in the study of PC disorders, with specific emphasis in those areas where consensus exists on the need to incorporate MFC into routine evaluation of MM and other clonal PC-related disorders.Cytometry Part B Clinical Cytometry 02/2010; 78(4):239-52. · 2.53 Impact Factor -
Article: Non-CLL-like monoclonal B-cell lymphocytosis in the general population: prevalence and phenotypic/genetic characteristics.
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ABSTRACT: Monoclonal B-cell lymphocytosis (MBL) indicates <5 × 10(9) peripheral blood (PB) clonal B-cells/L in healthy individuals. In most cases, MBL cells show similar phenotypic/genetic features to chronic lymphocytic leukemia cells-CLL-like MBL-but little is known about non-CLL-like MBL. PB samples from 639 healthy individuals (46% men/54% women) >40 years old (62 ± 13 years) with normal lymphocyte counts (2.1 ± 0.7 × 10(9)/L) were immunophenotyped using high-sensitive flow cytometry, based on 8-color stainings and the screening for >5 × 10(6) total PB leukocytes. Thirteen subjects (2.0%; 9 males/4 females, aged 73 ± 10 years; absolute lymphocyte count: 2.4 ± 0.8 × 10(9)/L) showed a non-CLL-like clonal B-cell population, whose frequency clearly increased with age: 0.4%, 3%, and 5.4% of subjects aged 40-59, 60-79, and ≥80 years, respectively. One single B-cell clone was detected in 9/13 cases, while two B-cell clones were found in 4/13 (n = 17 MBL populations). Nine MBL cell populations showed a CD5(-) phenotype (usually overlapping with marginal zone-derived (MZL) or lymphoplasmacytic (LPL) non-Hodgkin lymphoma (NHL) B-cells, or an unclassifiable NHL), but CD5(-/+d) (n = 3) and CD5(+) (n = 3 non-CLL-like MBL, consistent with a mantle-cell lymphoma (MCL)-like phenotype, and n = 2 CLL-like) MBL were also identified; iFISH supported the diagnosis in most cases. No preferential IGHV usage of B-cell receptor could be found. Twelve cases reevaluated at month +12 showed circulating clonal B-cells, at mean levels significantly higher than those initially detected. Non-CLL-like MBL cases frequently show biclonality, in association with MZL-, LPL-, MCL-like, or unclassifiable phenotypic profiles. As with CLL-like MBL, the frequency of non-CLL-like MBL increases with age, with a clear predominance of males.Cytometry Part B Clinical Cytometry 01/2010; 78 Suppl 1:S24-34. · 2.53 Impact Factor -
Article: Identification of leptomeningeal disease in aggressive B-cell non-Hodgkin's lymphoma: improved sensitivity of flow cytometry.
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ABSTRACT: Here, we evaluate the sensitivity and specificity of a new 11-parameter flow cytometry (FCM) approach versus conventional cytology (CC) for detecting neoplastic cells in stabilized CSF samples from newly diagnosed aggressive B-cell non-Hodgkin's lymphoma (B-NHL) at high risk of CNS relapse, using a prospective, multicentric study design. Moreover, we compared the distribution of different subpopulations of CSF leukocytes and the clinico-biologic characteristics of CSF+ versus CSF-, patients, in an attempt to define new algorithms useful for predicting CNS disease. Overall, 27 (22%) of 123 patients showed infiltration by FCM, while CC was positive in only seven patients (6%), with three other cases being suspicious (2%). CC+/FCM+ samples typically had more than 20% neoplastic B cells and/or >or= one neoplastic B cell/microL, while FCM+/CC- samples showed lower levels (P < .0001) of infiltration. Interestingly, in Burkitt lymphoma, presence of CNS disease by FCM could be predicted with a high specificity when increased serum beta2-microglobulin and neurological symptoms coexisted, while peripheral blood involvement was the only independent parameter associated with CNS disease in diffuse large B-cell lymphoma, with low predictive value. FCM significantly improves the sensitivity of CC for the identification of leptomeningeal disease in aggressive B-NHL at higher risk of CNS disease, particularly in paucicellular samples.Journal of Clinical Oncology 02/2009; 27(9):1462-9. · 18.37 Impact Factor -
Article: The effect of mesenchymal stem cells on the viability, proliferation and differentiation of B-lymphocytes.
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ABSTRACT: Mesenchymal stem cells are multilineage non-hematopoietic progenitor cells that play a key role in supporting the lymphohematopoietic system. Their distribution in bone marrow and secondary lymphoid organs allows an intimate interaction with T- and B-lymphocytes. While their effect on T-lymphocytes has been extensively analyzed, data on the effect of mesenchymal stem cells on B cells are more limited. We analyzed the effects of mesenchymal stem cells on B-lymphocytes and the pathways involved in these effects. The effect of MSC on the proliferation and viability of B cells was evaluated using MTT assays, annexin/7-amino-actinomycin D and propidium iodide staining. The B-cell maturation pattern was established using flow cytometry based on the expression of different markers related to the differentiation of B cells, such as CD38, CD138, CD19 and CCR7, and to the expression of surface and intracellular immunoglobulins. Finally, western blot assays were used to identify the pathways involved in the effects of mesenchymal stem cells on B-lymphocytes. Mesenchymal stem cells increased viability and blocked the cell cycle of B-lymphocytes in the G(0)/G(1) phase. In vitro exposure of B cells to plasmacytoid dendritic cells induced B-cell differentiation as shown by an increased number of CD38(++)/CD138(++) cells, which also displayed higher levels of cytoplasmic immunoglobulin and lower levels of CD19, CCR7 and surface immunoglobulin. Interestingly, this maturation pattern was inhibited by adding mesenchymal stem cells to the culture. Finally, mesenchymal stem cells modified the phosphorylation pattern of the extracellular response kinase 1/2 and p38 pathways which are both involved in B-cell viability, proliferation and activation. Mesenchymal stem cells increase B-cell viability while inhibiting proliferation, arresting B-lymphocytes in the G(0)/G(1) phase of the cell cycle. The presence of mesenchymal stem cells blocked B-cell differentiation as assessed by flow cytometry. Finally, mesenchymal stem cells modified the activation pattern of the extracellular response kinase and the p38 mitogen-activated protein kinase pathways in B-lymphocytes.Haematologica 09/2008; 93(9):1301-9. · 6.42 Impact Factor -
Article: Association between the proliferative rate of neoplastic B cells, their maturation stage, and underlying cytogenetic abnormalities in B-cell chronic lymphoproliferative disorders: analysis of a series of 432 patients.
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ABSTRACT: Limited knowledge exists about the impact of specific genetic abnormalities on the proliferation of neoplastic B cells from chronic lymphoproliferative disorders (B-CLPDs). Here we analyze the impact of cytogenetic abnormalities on the proliferation of neoplastic B cells in 432 B-CLPD patients, grouped according to diagnosis and site of sampling, versus their normal counterparts. Overall, proliferation of neoplastic B cells highly varied among the different B-CLPD subtypes, the greatest numbers of proliferating cells being identified in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Compared with normal B cells, neoplastic B-CLPD cells showed significantly increased S + G(2)/M-phase values in mantle cell lymphoma (MCL), B-chronic lymphocytic leukemia (B-CLL), BL, and some DLBCL cases. Conversely, decreased proliferation was observed in follicular lymphoma, lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM), and some DLBCL patients; hairy cell leukemia, splenic marginal zone, and MALT-lymphoma patients showed S + G(2)/M phase values similar to normal mature B lymphocytes from LN. Interestingly, in B-CLL and MCL significantly higher percentages of S + G(2)/M cells were detected in BM versus PB and in LN versus BM and PB samples, respectively. In turn, presence of 14q32.3 gene rearrangements and DNA aneuploidy, was associated with a higher percentage of S + G(2)/M-phase cells among LPL/WM and B-CLL cases, respectively.Blood 06/2008; 111(10):5130-41. · 9.90 Impact Factor -
Article: Impact of trisomy 12, del(13q), del(17p), and del(11q) on the immunophenotype, DNA ploidy status, and proliferative rate of leukemic B-cells in chronic lymphocytic leukemia.
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ABSTRACT: B-cell chronic lymphocytic leukemia (B-CLL) is a well-defined clinical entity with heterogeneous molecular and cytogenetic features. Here, we analyze the impact of trisomy 12, del(13q), del(17p), and del(11q) as determined by interphase fluorescence in situ hybridization analysis of purified neoplastic B-CLL cells on their immunophenotype, DNA ploidy status and proliferative rate.Overall, 111 of 180 (62%) B-CLL cases studied displayed one (50%) or more (12%) genetic abnormalities, del(13q) (35%) being more frequently detected than trisomy 12 (23%) followed by del(11q) (9%) and del(17p) (8%). Trisomy 12 was associated with a higher frequency of DNA aneuploidy, stronger expression of CD19, CD20, CD22, CD24, CD27, CD79b, CD38, and sIg and lower reactivity for CD43 with respect to cytogenetically nonaltered cases. In turn, cases with del(13q) displayed greater reactivity for CD20, FMC7, CD27, CD22, CD5, and bcl2, while del(11q) was associated with brighter expression of CD38, FMC7, CD25, and sIg. Hierarchical clustering analysis of the immunophenotype of B-CLL cases with cytogenetic abnormalities allowed the identification of three different groups of patients with increasing frequencies of trisomy 12, del(11q), and del(13q). Remarkably, none of the cytogenetic abnormalities analyzed except coexistence of 13q- and 17p- had a clear impact on the proliferative index of B-CLL cells.Cytometry Part B Clinical Cytometry 06/2008; 74(3):139-49. · 2.53 Impact Factor -
Article: Abnormalities of Peripheral Blood T Lymphocytes and Natural Killer Cells in Alcoholic Hepatitis Persist after a 3‐Month Withdrawal Period
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ABSTRACT: Present information about the behavior of the different lymphoid subsets in alcoholic hepatitis (AH), including cells displaying cyto-toxic activity, is scanty and contradictory. The aim of this study was to gain further insight into knowledge of the immunological abnormalities involved in AH and the possible role of ethanol (EtOH) consumption in these changes. We analyzed the distribution of a wide range of peripheral blood (PB) lymphoid subsets, both during active EtOH intake and after a 3-month withdrawal period, using multiple stainings with monoclonal antibodies and flow cytometry, as well as natural killer (NK) cytotoxic activity. AH patients entering the study were selected strictly; only those undergoing their first episode of AH with no other lesions at liver biopsy were enrolled. Regarding the alcohol intake period, the most striking finding was a significant increase of the absolute number of PB T cells affecting both CD4+ and CD8+ lymphocytes. These changes were associated with a higher expression of T-cell activation antigens, such as HLA DR and CD11c. Simultaneously, a significant increase in both NK cells (CD3−-/ CD56+) and the cytotoxic T cells coexpressing the CD3 and the CD56 molecules together with an increased NK cytotoxic activity were observed. By contrast, the CD19+/CD5+ B-cell subset was significantly decreased. No significant changes were observed with EtOH withdrawal except in CD5+ B lymphocytes, which returned to normal values. Our results show that, in AH patients, a significant expansion of both activated T cells and NK lymphocytes occurs in the PB, which is associated with an increased NK cytotoxic activity. Interestingly these abnormalities persist during the withdrawal period.Alcoholism Clinical and Experimental Research 05/2006; 21(4):672 - 676. · 3.34 Impact Factor -
Article: Differences in anti-apoptotic and multidrug resistance phenotypes in elderly and young acute myeloid leukemia patients are related to the maturation of blast cells.
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ABSTRACT: Elderly patients with acute myeloid leukemia (AML) have a less favorable outcome, which has been related, among other factors, to multidrug resistance (MDR) phenotypes. Freshly obtained erythrocyte-lysed bone marrow samples from 150 elderly patients (> 65 years) with de novo AML and 30 younger AML patients were analyzed using a 4-color immunofluorescence technique for quantitative expression of proteins associated with apoptosis (bcl-2, bax, APO2.7) and MDR (P-gp, MRP, LRP) in 3 blast cell subpopulations, defined according to their maturation stage. Although a homogeneous CD34+ blast cell population was more frequent in the elderly patients, (25% vs 7%, p=0.02), no statistically significant differences were detected between the two age groups in the expression of either apoptosis- or MDR-associated proteins, except for slightly higher quantities of LRP protein in the more immature CD34+ blast cell subset in the elderly AML cases (p=0.04). Interestingly, when different blast cell populations were compared, immature (CD34+) blast cells were characterized by higher levels of bcl-2 in both age groups and lower levels of APO2.7 in the elderly group. In addition, higher P-gp levels were found in CD34+ blast cells than in CD34-- ones in elderly AML patients. Reactivity for LRP was low in both elderly and younger patients. In summary, our results suggest that the higher resistance to chemotherapy observed in elderly AML patients could be related to a higher incidence of cases with a CD34+ homogeneous blast cell population, since these blast cells frequently display a more pronounced anti-apoptotic and MDR1 phenotype.Haematologica 01/2005; 90(1):54-9. · 6.42 Impact Factor -
Article: Intratumoral patterns of clonal evolution in meningiomas as defined by multicolor interphase fluorescence in situ hybridization (FISH): is there a relationship between histopathologically benign and atypical/anaplastic lesions?
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ABSTRACT: Meningiomas are cytogenetically heterogeneous tumors in which chromosome gains and losses frequently occur. Based on the intertumoral cytogenetic heterogeneity of meningiomas, hypothetical models of clonal evolution have been proposed in these tumors which have never been confirmed at the intratumoral cell level. The aim of this study was to establish the intratumoral patterns of clonal evolution associated with chromosomal instability in individual patients as a way to establish tumor progression pathways in meningiomas and their relationship with tumor histopathology and behavior. A total of 125 meningioma patients were analyzed at diagnosis. In all cases, multicolor interphase fluorescence in situ hybridization (iFISH) studies were performed on fresh tumor samples for the detection of quantitative abnormalities for 11 different chromosomes. In addition, overall tumor cell DNA content was measured in parallel by flow cytometry. iFISH studies were also performed in parallel on tissue sections in a subset of 30 patients. FISH studies showed that 56 (45%) of the 125 cases analyzed had a single tumor cell clone, all these cases corresponding to histologically benign grade I tumors. In the remaining cases (55%) more than one tumor cell clone was identified: two in 45 cases (36%), three in 19 (15%), and four or more clones in five cases (4%). Overall, flow cytometric analysis of cell DNA contents showed the presence of DNA aneuploidy in 44 of these cases (35%), 30% corresponding to DNA hyperdiploid and 5% to hypodiploid cases; from the DNA aneuploid cases, 35 (28%) showed two clones and 9 (7%) had three or more clones. A high degree of correlation (r >/= 0.89; P < 0.001) was found between FISH and flow cytometry as regards the overall quantitative DNA changes detected with both techniques, the former being more sensitive. Among the cases with chromosome abnormalities, the earliest tumor cell clone observed was frequently characterized by the loss of one or more chromosomes (64% of all meningiomas); loss of either a single chromosome 22 or, less frequently, of a sex chromosome (X or Y) and del (1p) was commonly found as the single initial cytogenetic aberration (30%, 5%, and 5% of the cases, respectively). Interestingly, an isolated loss of chromosome 22 was only found as the initial abnormality in one out of 14 atypical/anaplastic meningiomas, while the same cytogenetic pattern was present in the ancestral tumor cell clone of 32% of the benign tumors. Cytogenetic patterns based on chromosome gains were found in the ancestral tumor cell clone in 4% of the patients, 2% corresponding to tetraploid tumors. Overall, cytogenetic evolution of the earliest tumor cell clones was frequently associated with tetraploidization (31%). Our results show that meningiomas are genetically heterogeneous tumors that display different patterns of numerical chromosome changes, with the presence of more than one tumor cell clone detected in almost half of the cases including all atypical/anaplastic cases. Interestingly, the pathways of intratumoral clonal evolution observed in the benign tumors were different from those observed in atypical/anaplastic meningiomas, suggesting that the latter tumors might not always represent a more advanced stage of histologically benign meningiomas.Journal of Molecular Diagnostics 12/2004; 6(4):316-25. · 3.58 Impact Factor -
Article: CD34+ cells from acute myeloid leukemia, myelodysplastic syndromes, and normal bone marrow display different apoptosis and drug resistance-associated phenotypes.
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ABSTRACT: Myelodysplastic syndromes and acute myeloid leukemia (AML) are heterogeneous disorders in which conflicting results in apoptosis and multidrug resistance (MDR) have been reported. We have evaluated by multiparameter flow cytometry the expression of apoptosis- (APO2.7, bcl-2, and bax) and MDR-related proteins [P-glycoprotein (P-gp), multidrug resistance protein (MRP), and lung resistance protein (LRP)] specifically on bone marrow (BM) CD34+ cells, and their major CD32-/dim and CD32+ subsets, in de novo AML (n=90), high-risk myelodysplastic syndrome (n=9), and low-risk myelodysplastic syndrome (n=21) patients at diagnosis, and compared with normal BM CD34+ cells (n=6). CD34+ myeloid cells from AML and high-risk myelodysplastic syndrome patients displayed higher expression of bcl-2 (P <0.0001) and lower reactivity for APO2.7 (P=0.002) compared with low-risk myelodysplastic syndrome and normal controls. Similar results applied to the two predefined CD34+ myeloid cell subsets. No significant differences were found in the expression of P-gp, MRP, and LRP between low-risk myelodysplastic syndrome patients and normal BM, but decreased expression of MRP (P <0.03) in AML and high-risk myelodysplastic syndromes and P-gp (P=0.008) in high-risk myelodysplastic syndromes were detected. Hierarchical clustering analysis showed that low-risk myelodysplastic syndrome patients were clustered next to normal BM samples, whereas high-risk myelodysplastic syndromes were clustered together and mixed with the de novo AML patients. In summary, increased resistance to chemotherapy of CD34+ cells from both AML and high-risk myelodysplastic syndromes would be explained more appropriately in terms of an increased antiapoptotic phenotype rather than a MDR phenotype. In low-risk myelodysplastic syndromes abnormally high apoptotic rates would be restricted to the CD34- cell compartments.Clinical Cancer Research 11/2004; 10(22):7599-606. · 7.74 Impact Factor -
Article: Immunophenotypic analysis of mast cells in mastocytosis: When and how to do it. Proposals of the Spanish Network on Mastocytosis (REMA).
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ABSTRACT: Mastocytosis is a term used for a heterogeneous group of disorders characterized by an abnormal proliferation and accumulation of mast cells (MCs) in one or multiple tissues including skin, bone marrow, liver, spleen, and lymph nodes, among others. In recent years, multiparameter flow cytometric studies have shown that pathologic MCs from patients with mastocytosis display unique aberrant immunophenotypic characteristics as compared with normal MCs. Among other features, pathologic MCs show aberrant expression of CD25 and CD2 antigens and abnormally high levels of the CD11c and CD35 complement receptors, the CD59 complement regulatory molecule, the CD63 lysosomal membrane antigen, and the CD69 early-activation antigen. In addition, MCs from mastocytosis express abnormally low levels of CD117 and unexpectedly high light scatter and autofluorescence characteristics. These aberrant immunophenotypic features are of great relevance for the assessment of tissue involvement in mastocytosis with consequences in the diagnosis, classification, and follow-up of the disease and in its differential diagnosis with other entities. In this paper we provide the reader with information for the objective and reproducible identification of pathologic MCs by using quantitative multiparametric flow cytometry, information for their phenotypic characterization, and the criteria currently used for a correct interpretation of the immunophenotypic results obtained.Cytometry Part B Clinical Cytometry 04/2004; 58(1):1-8. · 2.53 Impact Factor -
Article: Immunophenotypic analysis of myelodysplastic syndromes.
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ABSTRACT: In contrast with hematologic malignancies in which the value of immunophenotypic studies is well established, information on the immunophenotypic characteristics of myelodysplastic syndromes (MDS) is scanty. The main goal of the present study was to explore the immunophenotypic differences between patients with MDS and normal individuals, including changes in distribution of cell lineages as well as phenotypic aberrations and blockades in cell maturation pathways. In MDS the proportion of bone marrow CD34+ cells was higher than in normal patients but the most immature progenitors (CD34+CD38-) were less represented. By contrast the proportion of myelomonocytic CD34+ cells was greater than in normal individuals, translating into an increased myeloid/non-myeloid CD34+ hematopoietic progenitor cell ratio. This suggests that in MDS, the majority of CD34+ cells are already committed to the myeloid lineage. Upon analyzing the granulo-monocytic differentiation pathway, MDS patients showed an increased proportion of monocytic cells with a decreased percentage of cells of neutrophil lineage, leading to a lower neutrophil/monocytic cell ratio. Maturational arrests in the monocytic but not in the neutrophil differentiation pathway were observed. In refractory anemia with excess blasts in transformation (RAEB-t) such blockades mainly occurred during the earliest stages of differentiation but in the other MDS subtypes they occurred in later stages. Phenotypic aberrations occurred in 90% of patients and a high proportion of cases showed >=2 aberrations. In summary, our results show that, in addition to an abnormal distribution of the bone marrow cell compartment, MDS patients frequently show aberrant phenotypes and maturational arrests. Some of these features may help in cases in which the diagnosis of MDS is questionable.Haematologica 04/2003; 88(4):402-7. · 6.42 Impact Factor -
Article: Overexpression of complement receptors and related antigens on the surface of bone marrow mast cells in patients with systemic mastocytosis
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ABSTRACT: Depending on their stage of maturation and other factors, mast cell (MC) subsets differ from each other in terms of the expression of complement-associated antigens. This study analysed the expression of various complement-related cell surface antigens (CD11b/CR3, CD11c/CR4, CD35/CR1, CD55/DAF, CD59/MIRL, CD88/C5aR) on bone marrow mast cells (BMMC) in patients suffering from systemic mastocytosis (SM), other haematological diseases and non-haematological disorders (control groups). Expression of complement-associated cell surface antigens was analysed by flow cytometry. There were clear immunophenotypic differences between BMMC obtained from patients with SM and those from the control subjects: the percentage of patients expressing surface CD11c, CD35 and CD88 was significantly higher in patients with SM (76%, 100%, 54%) than in the control subjects (58%, 11%, 18%) (P < 0·05). In addition, the levels of CD11c, CD35 and CD88 expressed per MC (sites per cell) were significantly higher (P < 0·05) in SM than in the control group. Expression of the complement regulatory molecules CD55 and CD59 was detected in BMMC in all patients analysed. However, the levels of CD59 per BMMC were higher in patients with SM as compared with the control subjects, which could help to explain the formation of BMMC aggregates in the former group of individuals. Together, our results showed that BMMC in systemic mastocytosis overexpressed the cell surface membrane receptors involved in binding of complement components and complement-mediated cell activation. Whether this pathological expression of complement receptors is of pathophysiological significance remains to be determined.British Journal of Haematology 01/2003; 120(2):257 - 265. · 4.94 Impact Factor
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Institutions
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2000–2012
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Universidad de Salamanca
- • Departamento de Medicina y Servicio General de Citometría
- • Departamento de Medicina
Salamanca, Castile and Leon, Spain
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2005–2008
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Hospital Universitario de Salamanca
Salamanca, Castile and Leon, Spain
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2006
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Universidad de Alcalá
Alcalá de Henares, Madrid, Spain
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2003–2004
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Hospital Universitario Ramón y Cajal
Madrid, Madrid, Spain
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