M Gonzalez

Universidad de Salamanca, Salamanca, Castile and Leon, Spain

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Publications (42)169.23 Total impact

  • Article: Prognostic implications of DNA aneuploidy in 156 untreated multiple myeloma patients
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    ABSTRACT: In this study the incidence of DNA aneuploidy in a large series of untreated multiple myeloma (MM) patients was assessed in order to determine its clinical and prognostic significance. A total of 156 MM patients were included in the study. DNA measurements were performed in all cases at diagnosis using two different flow cytometry methods: (1) propidium iodide (PI) staining on isolated nuclei, and (2) CD38/PI double staining on whole cells. The DNA ploidy status was correlated with the most relevant clinical and haematological disease characteristics. From the 156 cases analysed, 91 (58%) were aneuploid (56% hyperdiploid and 2% hypodiploid). The correlation between the two techniques on the detection of DNA aneuploidy was excellent, although CD38/PI double staining would be preferable in cases with <5% of DNA aneuploid plasma cells (PC). Upon comparing the clinical and haematological disease characteristics of hyperdiploid versus diploid cases, the former group was characterized by a lower age, reduced incidence of anaemia, lower 02M levels, higher proliferative activity within the residual normal haemopoietic cells, increased expression of CD 5 6 antigen in PC, and higher proportion of PB CD4+ T cells. In contrast, diploid cases had a higher expression of the CD10, CD20 and CD15 antigens and greater numbers of PB CD56+CD3 NK cells (P < 0–05). Circulating PC were identified in six cases, all being diploid. Overall survival was significantly longer in hyperdiploid compared to diploid MM (P = 0–02).
    British Journal of Haematology 03/2008; 90(1):106 - 112. · 4.94 Impact Factor
  • Article: Hyperhomocysteinemia is a risk factor of recurrent coronary event in young patients irrespective to the MTHFR C677T polymorphism.
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    ABSTRACT: Despite the well-known pro-coagulant effect of hyperhomocysteinemia, data is limited regarding the result on recurrent coronary event (RCE) in young people. One hundred and forty patients <55 years old with a first acute coronary syndrome (ACS) were prospectively followed for a mean (+/-S.D.) follow-up of 49+/-14 months in order to investigate the relationship between homocysteine levels (tHcy) at admission and the incidence of RCE. The tHcy values were divided into quartiles to examine their relationship with end points. Furthermore, we determined the effect of C677T methylene tetrahydrofolate reductase (MTHFR) polymorphism, as well as other risk factors for developing a RCE. The median plasma homocysteine concentration was 9.6 mumol/L (interquartile range, 3.7). In the screening of MTHFR C677T polymorphism in patients with ACS, the T allele frequency was 0.4 and the genotype frequency distributions were in Hardy-Weinberg equilibrium. At time of final evaluation, 49 (35%) of the 140 valuable patients had developed a RCE. Increasing numbers of RCE were observed for increasing quartiles of tHcy according to Kaplan-Meier survival (Log-rank test=0.0092). The MTHFR C677T polymorphism was not associated with an increased incidence of RCE. In multivariate analysis, the variables independently associated with a higher risk of RCE were age older than 45 years [HR=2.7; (95% CI, 1.3-6.1); p=0.030], body mass index more than 25 [HR=2.6; (95% CI, 1.1-5.9); p=0.034] and tHcy levels into quartile 4 (tHcy>12.37 mumol/L) [HR=2.5; (95% CI, 1.1-4.7); p=0.04]. Elevated plasma homocysteine level at admission is an independent risk factor for RCE after the first episode of ACS in young patients irrespective of the status of MTHFR C677T.
    Thrombosis Research 01/2007; 119(6):691-8. · 2.44 Impact Factor
  • Article: TCRgammadelta+ large granular lymphocyte leukemias reflect the spectrum of normal antigen-selected TCRgammadelta+ T-cells.
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    ABSTRACT: T-cell large granular lymphocytes (LGL) proliferations range from reactive expansions of activated T cells to T-cell leukemias and show variable clinical presentation and disease course. The vast majority of T-LGL proliferations express TCRalphabeta. Much less is known about the characteristics and pathogenesis of TCRgammadelta+ cases. We evaluated 44 patients with clonal TCRgammadelta+ T-LGL proliferations with respect to clinical data, immunophenotype and TCR gene rearrangement pattern. TCRgammadelta+ T-LGL leukemia patients had similar clinical presentations as TCRalphabeta+ T-LGL leukemia patients. Their course was indolent and 61% of patients were symptomatic. The most common clinical manifestations were chronic cytopenias - neutropenia (48%), anemia (23%), thrombocytopenia (9%), pancytopenia (2%) - and to a lesser extent splenomegaly (18%). Also multiple associated autoimmune (34%) and hematological (14%) disorders were found. Leukemic LGLs were predominantly positive for CD2, CD5, CD7, CD8, and CD57, whereas variable expression was seen for CD16, CD56, CD11b, and CD11c. The Vgamma9/Vdelta2 immunophenotype was found in 48% of cases and 43% of cases was positive for Vdelta1, reflecting the TCR-spectrum of normal TCRgammadelta+ T-cells in adult PB. Identification of the well-defined post-thymic Vdelta2-Jdelta1 selection determinant in all evaluable Vgamma9+/Vdelta2+ patients, is suggestive of common (super)antigen involvement in the pathogenesis of these TCRgammadelta+ T-LGL leukemia patients.
    Leukemia 04/2006; 20(3):505-13. · 9.56 Impact Factor
  • Article: Chimerism analysis following allogeneic peripheral blood stem cell transplantation with reduced-intensity conditioning.
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    ABSTRACT: We have performed a prospective study to evaluate early chimerism and its kinetics after allogeneic peripheral blood stem cell transplantation among 68 patients who received a reduced-intensity conditioning (RIC) regimen with fludarabine plus melphalan (n=40) or busulphan (n=28). Chimerism was analyzed by polymerase chain reaction amplification of short tandem repeats in unfractionated (UF) and/or fractionated nucleated cells from bone marrow and peripheral blood (PB). All of the patients showed initial donor engraftment and no patient presented primary or secondary graft failure. In UF samples, the probability of achieving stable complete donor chimerism (CDC) in PB within the first 6 months was 70% on day +30, 85% on day +100 and 95% on day +180. CDC in granulocytes was observed in nearly all cases from day +30 onwards. CDC in T cells, however, differed among melphalan and busulphan recipients during the first 3 months (100 vs 0% on day +30 and 93 vs 20% on day +90, respectively). In multivariate analysis, the only significant variable associated with the achievement of early CDC was having received more than two lines of chemotherapy pretransplant (P<0.02). No correlation was found between the rate of achieving early CDC and the occurrence of acute graft-versus-host disease (GVHD) or disease progression post-transplant. In multivariate analysis, the only variable that influenced the incidence of disease progression post-transplant was the development of chronic extensive GVHD (P<0.05). In conclusion, a state of CDC is readily obtained within the first 6 months after our RIC protocols. Donor myeloid engraftment occurs rapidly in all cases, while early T-cell CDC is more common in more immunosuppressed hosts and, perhaps, in melphalan recipients.
    Bone Marrow Transplantation 03/2003; 31(5):387-92. · 3.75 Impact Factor
  • Article: Chimerism and minimal residual disease monitoring after reduced intensity conditioning (RIC) allogeneic transplantation.
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    ABSTRACT: Since graft-versus-leukemia (GVL) is the main weapon for disease eradication after reduced intensity conditioning (RIC) allogeneic SCT, the availability of sensitive and specific techniques to monitor changes in tumor load after transplant are especially helpful. These minimal residual disease techniques would allow an early intervention in the event of low tumor burden, for which immunotherapy is highly effective. Some authors have found an association between persistence of MRD, mixed chimerism and risk of relapse. Nevertheless, data from the literature remain contradictory and further correlations should be established, especially in RIC transplants. In this study we have analyzed the impact of MRD and chimerism monitoring on the outcome of 34 patients undergoing RIC allogeneic SCT who were considered poor candidates for conventional transplantation due to advanced age or other concurrent medical conditions. At day +100 25 (75%) patients reached complete remission (CR), there were five (15%) partial responses and three patients progressed. Incidence of grade 2-4 aGVHD and extensive cGVHD were 35% and 58%, respectively. Sixteen percent of patients developing aGVHD relapsed as compared to 47% in those without aGVHD (P = 0.03) and also 10% of patients developing cGVHD relapsed as compared to 50% relapses in those without cGHVD (P = 0.03). Four patients (12%) died due to early (n = 1) and late (n = 3) transplant-related mortality. After a median follow-up of 15 months, 24 out of the 34 patients remain alive. Projected overall survival and disease-free survival at 3 years are 68% and 63%, respectively. Early chimerism analysis showed 67% of patients with complete chimerism (CC) in bone marrow (BM), 86% in peripheral blood (PB), 89% in granulocytes and 68% in T lymphocytes. On day +100, these figures were 68%, 79%, 90% and 73%, respectively, and on day +180 there were 83% patients with CC in BM, 100% in PB, 100% in granulocytes and 100% in T lymphocytes. We observed a trend to a higher incidence of relapse in patients with mixed chimerism (MC) as compared to patients with CC. MRD monitoring by flow cytometry and/or RT-PCR analysis was performed in 23 patients. MRD assessment on days +21 to +56 after transplant allowed identification of patients at risk of relapse. In this sense, seven out of 12 patients (58.3%) who had positive MRD on days +21 to +56 relapsed as compared to none out of 11 patients who had negative MRD (P = 0.002). Of the seven patients with criteria to monitor MRD who relapsed after transplant, all but one remained MRD positive until relapse. By contrast, 10 patients remained MRD negative and all of them are in continuous CR. In nine additional patients, persistence of MRD or mixed chimerism was observed after transplant and withdrawal of cyclosporin with or without DLI was performed. Only two out of these nine patients relapsed. MRD clearance was preceded by CC and GVHD. In conclusion, in our study we found that RIC allogeneic transplantation can be used in patients considered poor candidates for conventional transplantation due to advanced age or other concurrent medical conditions with both low toxicity and low transplant-related mortality. Simultaneous studies of both chimerism and MRD are a useful tool in order to predict risk of relapse in patients undergoing RIC transplants and so can be helpful for individualizing treatment strategies after transplant.
    Leukemia 09/2002; 16(8):1423-31. · 9.56 Impact Factor
  • Article: Immunophenotypic analysis of the TCR-Vbeta repertoire in 98 persistent expansions of CD3(+)/TCR-alphabeta(+) large granular lymphocytes: utility in assessing clonality and insights into the pathogenesis of the disease.
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    ABSTRACT: At present, a major challenge in the initial diagnosis of leukemia of large granular lymphocytes (LGLs) is to establish the clonal nature of the expanded population. In the present study we have analyzed by flow cytometry immunophenotyping the TCR-Vbeta repertoire of 98 consecutive cases of persistent expansions of CD4(+) or CD8(+bright) CD3(+)/TCR-alphabeta(+) LGLs and compared the results with those obtained in molecular studies of TCR-beta gene rearrangements. Fifty-eight cases were considered to be monoclonal in molecular studies whereas in the remaining 40 cases there was no evidence for monoclonality (11 cases were considered oligoclonal and 29 polyclonal). The TCR-Vbeta repertoire was biased to the preferential use of one or more TCR-Vbeta families in 96% of cases, a total of 124 TCR-Vbeta expansions being diagnosed: one TCR-Vbeta expansion in 71 cases and two or more TCR-Vbeta expansions in 23 cases. The highest TCR-Vbeta expansion observed in each case was higher among monoclonal (74 +/- 19%) as compared to nonmonoclonal cases (24 +/- 14%) (P = 0.001), as did the fraction of LGLs that exhibited a TCR-Vbeta-restricted pattern (86 +/- 16% and 42 +/- 23%, respectively; P = 0.0001); by contrast, the proportion of cases displaying more than one TCR-Vbeta expansion was higher in the latter group: 7% versus 48%, respectively (P = 0.001). Results obtained in oligoclonal cases were intermediate between those obtained in polyclonal and monoclonal cases and similar results were observed for CD4(+) as for CD8(+bright) T-cell expansions. TCR-Vbeta families expressed in CD8(+bright) T-cell-LGL proliferations showed a pattern of distribution that mimics the frequency at which the individual TCR-Vbeta families are represented in normal peripheral blood T cells. Assuming that a given proliferation of LGLs is monoclonal whenever there is an expansion of a given TCR-Vbeta family of at least 40% of the total CD4(+) or CD8(+bright) T-cell compartment, we were able to predict clonality with a sensitivity of 93% and a specificity of 80%. By increasing the cut-off value to 60%, sensitivity and specificity were of 81% and 100%. In summary, our results suggest that flow cytometry immunophenotypic analysis of the TCR-Vbeta repertoire is a powerful screening tool for the assessment of T-cell clonality in persistent expansions of TCR-alphabeta(+) LGLs.
    American Journal Of Pathology 12/2001; 159(5):1861-8. · 4.89 Impact Factor
  • Article: Clinical significance of CD34+ cell dose in long-term engraftment following autologous peripheral blood stem cell transplantation.
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    ABSTRACT: The number of CD34+ cells has been described as the best parameter for predicting the quality of engraftment in peripheral blood progenitor cell (PBPC) transplantation in the early post-transplant period. In this study we have determined the optimal number of CD34+cells in order to maintain engraftment in the long term in a series of 100 patients receiving autologous PBPC transplantation. Based on our previous experience on the speed of early hematopoietic recovery, four subgroups of patients were established: patients infused less than 0.75 x 106/kg CD34+ (n = 9), 0.75 to 1.25 (n = 24), 1.25 to 2.0 (n = 37) and more than 2.0 (n = 30). These groups were designated as low, intermediate-low, intermediate-high and high CD34 groups, respectively. Transitory loss of neutrophil engraftment was observed in 67%, 30%, 16% and 6% of patients in the four mentioned CD34 groups respectively, with statistically significant differences between the different groups. Significant differences were also observed between the low CD34 group and the rest of the groups as regards platelet and red blood cell transfusion requirements, fever episodes, days of hospitalization and antibiotic requirements throughout the first year. Our results show that the dose of CD34+ cells influences engraftment also in the late post-transplant period, and correlates with transfusion and antibiotic requirements, fever episodes and days of hospitalization during the first year post-transplant.
    Bone Marrow Transplantation 01/2000; 24(12):1279-83. · 3.75 Impact Factor
  • Article: The flow cytometric pattern of CD34, CD15 and CD13 expression in acute myeloblastic leukemia is highly characteristic of the presence of PML-RARalpha gene rearrangements.
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    ABSTRACT: Rapid identification of AML patients carrying the t(15;17) translocation for treatment decision-making is currently made on the basis of morphologic screening. However, the existence of both false positives and negatives highlights the need for more objective methods of screening AML cases and further molecular confirmation of the t(15;17) translocation. In the present study we analyzed a total of 111 AML cases in order to investigate whether immunophenotyping based on the assessment of multiple-stainings analyzed at flow cytometry could improve the sensitivity and specificity of morphologic identification of acute promyelocytic leukemia (APL) carrying the t(15;17) translocation. FISH analysis was used as a complementary technique for cases in which morphology and molecular biology yielded discrepant results. Concordant results between morphology and RT-PCR were found in 102/111 (91.8%) cases: 34 patients had M3/PML-RARalpha+ and 68 non-M3/PML-RARalpha- disease. Nine cases showed discrepants results. Multivariate analysis showed that the best combination of immunologic markers for discriminating between M3/PML-RARalpha+ and non-M3/PML-RARalpha- cases was that of the presence of heterogeneous expression of CD13, the existence of a single major blast cell population, and a characteristic CD34/CD15 phenotypic pattern (p<0.02). A score system based on these parameters was designed, and the 34 M3/PML-RARalpha+ cases showed a score of 3 (presence of the 3 phenotypic characteristics). In contrast, only 1 out of the 68 (1.3%) non-M3/PML-RARalpha- cases had this score, most o these latter cases (53/68, 78%) scoring either 0 or 1. Therefore, among these cases, immunophenotyping showed a sensitivity of 100% and a specificity of 99% for predicting PML/RARalpha gene rearrangements. Of the 9 cases in which morphology and molecular biology results were discrepant, four cases displayed M3 morphology without PML/RARalpha rearrangements by RT-PCR. In only one of these 4 cases did the immunophenotype score 3, this being the only FISH positive case. From the remaining five discrepant cases (non-M3 morphology while positive for PML/RARalpha) two cases had a phenotypic score of 3 and were FISH positive while the other three were negative by FISH. Upon repeating RT-PCR studies, two of these latter three cases became negative. Our results show that immunophenotyping may be of great value for quick screening of APL with PML/RARalpha rearrangements.
    Haematologica 05/1999; 84(5):405-12. · 6.42 Impact Factor
  • Article: BEAM chemotherapy followed by autologous stem cell support in lymphoma patients: analysis of efficacy, toxicity and prognostic factors.
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    ABSTRACT: In the present paper, we evaluate tolerability, outcome and prognostic factors in patients with poor prognosis non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) when uniformly treated with BCNU, etoposide, cytarabine and melphalan (BEAM) and autologous stem cell transplant (ASCT). On hundred and forty-eight patients with NHL (n = 112) or HD (n = 36) received BEAM followed by infusion of bone marrow (n = 55), peripheral blood stem cells (n = 79) or both (n = 14). Twenty-eight patients had low-grade lymphoma (LGL), 68 intermediate- and 16 high-grade lymphoma (IGL). Within the NHL group, 21 patients were in 2nd or subsequent complete remission (CR) at transplant, 34 had sensitive disease and 11 resistant disease; 46 patients were transplanted in 1st CR due to the presence of > or = 2 adverse prognostic features at diagnosis or to a slow CR. Of the HD patients at transplant 17 had active disease, 16 were in > or = 2 CR and three in 1st CR. The overall percentage of toxic deaths was 5.4%, while in the group of patients transplanted with PBSC it was only 1.3%. NHL patients: 78% were in CR following ASCT, including 25 out of 45 patients (56%) who were transplanted with active disease. Only two of the 11 patients transplanted with resistant disease achieved CR. Incidence of overall survival (OS) and disease-free survival (DFS) at 3 years was 65 and 75%, respectively. As far as histology was concerned, OS was significantly better for patients with LGL in comparison with IGL (88 vs 56%) (P = 0.002). DFS was significantly higher for patients transplanted in first CR or first partial remission (PR) than it was for those transplanted in a later CR or PR (86 vs 53%) (P = 0.02). Multivariate analysis for OS showed that histology, bulky disease, poor performance status at transplant and achievement of CR were independent prognostic factors. In addition, a high number of infused MNC was associated with poor DFS. HD patients: 30 (83%) were in CR after transplantation, with 25 maintaining CR at the end of the study. Only one of the four patients transplanted with resistant disease reached CR. Incidence of OS and DFS at 3 years was 78 and 81%. DFS was similar for patients transplanted with early or late relapse (95 and 93%). With multivariate analysis, the only independent variable for OS was CR after transplant. In conclusion, the present results demonstrate the efficacy and low toxicity of the BEAM regimen in high-risk lymphoma patients with sensitive disease. Other strategies should be investigated for patients with refractory lymphoma.
    Bone Marrow Transplantation 09/1997; 20(6):451-8. · 3.75 Impact Factor
  • Article: Alternating mini-BEAM/ESHAP as salvage therapy for refractory non-Hodgkin's lymphomas.
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    ABSTRACT: Mini-BEAM and ESHAP are two non-cross-resistant salvage regimens that have been used separately in patients with lymphoma. The aim of the present study was to investigate the efficacy of the combination of these two regimens, administered in alternating cycles, as salvage therapy for refractory non-Hodgkin's lymphoma (NHL) patients. A total of 28 patients were included in the study: 14 patients were primary refractory, seven were partial responders, and seven were in relapse. The alternating cycles of mini-BEAM and ESHAP were given until there was maximum response or progression. The overall response rate to mini-BEAM/ESHAP was 39%; 25% of patients achieved a complete response and 14% a partial response. Nevertheless, it should be noted that none of the primary refractory patients responded to this protocol. Nine of the 11 patients who responded to mini-BEAM/ESHAP were consolidated with autologous transplantation using BEAM as a conditioning regimen. The survival at 3 years in this group of 11 patients who responded to the salvage regimen is 64%, with a disease-free survival of 67% at 2 years. No major toxic effects were observed with mini-BEAM/ESHAP. Myelosuppression was the most frequent complication, especially with the mini-BEAM cycles. Other toxicities were infrequent and no treatment-related deaths were observed. These results suggest that alternating mini-BEAM/ESHAP chemotherapy is a safe regimen that is effective in partial responders or relapsing patients with NHL who have sensitive disease, but not in primary refractory patients. Moreover, although this therapy has a potential advantage, combining as it does two non-cross-resistant regimens, it does not seem superior to ESHAP alone.
    Annals of Hematology 03/1997; 74(2):79-82. · 2.62 Impact Factor
  • Article: Expression of the CD117 antigen (c-Kit) on normal and myelomatous plasma cells.
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    ABSTRACT: The surface expression of CD117 on plasma cells (PCs) from normal individuals and patients with multiple myeloma (MM) has been analysed using triple-stained cells for flow cytometry. In addition, the clinical significance of CD117 expression in MM patients and its possible value for the evaluation of minimal residual disease was explored. A total of 11 healthy volunteers and 56 untreated MM patients were included in the study. The expression of CD117 was analysed by flow cytometry, using simultaneous staining with the MAbs BB4, CD117 and CD38. Cell acquisition was performed in two consecutive steps using a live gate drawn on SSC/CD38 cells and a total of 300,000 events were acquired. For data analysis, the Paint-a-Gate Plus software (Becton Dickinson) was used. PCs were identified according to their strong reactivity for CD38 and their positivity for BB4, as well as by their light scatter distribution. Dilution experiments of CD117+ myelomatous PCs with normal bone marrow (BM) cells were performed in order to assess the sensitivity level of the technique for detection of CD117+ residual PCs. None of the PCs from normal BM samples showed reactivity for the CD117 antigen. In contrast, CD117 antigen was present in 18/56 MM patients (32%), the proportion of positive cells in these cases being as high as 92.1 +/- 9%. Therefore, within PC lineage the c-Kit antigen would be restricted to the myelomatous population and thus could be considered as a 'tumour-associated marker' for monitoring minimal residual disease in about one third of MM patients. Dilution experiments indicate that the detection limit with this marker would be 10(-4) (one myelomatous PC/10(4) normal BM cells). Upon comparing the clinical and haematological disease characteristics of CD117-positive and CD117-negative cases, no significant differences were found.
    British Journal of Haematology 01/1997; 95(3):489-93. · 4.94 Impact Factor
  • Article: A randomized study comparing the effect of GM-CSF and G-CSF on immune reconstitution after autologous bone marrow transplantation.
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    ABSTRACT: Haemopoietic growth factors (HGFs) have been shown to accelerate recovery from severe neutropenia after autologous bone marrow transplantation (ABMT) but their effect on immune reconstitution is not well defined. The present study compares, through randomized trial, the in vivo effect of GM-CSF and G-CSF administration on the immune recovery of patients who underwent ABMT. For that purpose, we have sequentially analysed 14 different T, B and NK lymphoid cell subsets using appropriate dual staining during the first year following transplant (days +6, +17, +31, +66, +90, +120, +180, +360). 24 patients with lymphoproliferative disorders (20 lymphomas and four multiple myelomas) and who had undergone ABMT were included in the study. The median age was 43 years (range 22-62 years). All lymphoma patients were homogenously conditioned with BEAM. Our results show that both GM-CSF and G-CSF aid T-cell (CD3+/alpha beta) recovery though their contribution varies depending on the T-cell subset analysed. G-CSF contributed to a significantly faster recovery of CD8+ cells (P = 0.03). The CD8+ cell regeneration was produced mainly by activated cells (CD38+/HLA-DR+) which lacked the CD11b antigen. In contrast, GM-CSF favoured the regeneration of CD4+ cells (through both the CD45RO+ and CD45RA+ subset), leading to a higher CD4+:CD8+ ratio (P = 0.007). No statistically significant differences were detected in the three groups of patients as regards both the recovery of NK cells and NK activity. Furthermore, the use of HGF did not seem to exert a significant influence on the recovery of B lymphocytes. This recovery was based on the CD5+ subpopulation that showed a rapid rise after the first month. We suggest that G-CSF and GM-CSF not only influence myeloid recovery, but also regeneration of the immune system after ABMT.
    British Journal of Haematology 08/1996; 94(1):140-7. · 4.94 Impact Factor
  • Article: Incidence of chromosome numerical changes in multiple myeloma: fluorescence in situ hybridization analysis using 15 chromosome-specific probes.
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    ABSTRACT: The presence of complex karotypes with frequent numerical and structural abnormalities has been reported in 20 to 50% of multiple myeloma (MM) patients. This variability is mainly due to the difficulty of conventional cytogenetics to obtain tumor metaphases representative of all possible neoplastic clones in MM. To gain insight into the real incidence of numerical chromosome changes in MM we have studied by fluorescence in situ hybridization technique 15 different human chromosomes, 1, 3, 6, 7, 8, 9, 10, 11, 12, 13, 15, 17, 18, X, and Y, in a series of 52 MM patients. In all cases, the DNA index assessed by a propidium iodide/CD38 double-staining technique with flow cytometry was simultaneously investigated for correlation, with fluorescence in situ hybridization results. Additional aims of this study were 1) to analyze whether the abnormalities detected were common to all plasma cells or were present in only a subpopulation of tumor cells, 2) to explore changes caused by disease progression, and 3) to establish possible associations among the altered chromosomes. Although the overall incidence of numerical abnormalities was 67%, this frequency increased to 80% in the 41 cases in which 7 or more chromosomes were analyzed. Trisomies were significantly more common than monosomies (84% versus 16%). Chromosomes 9 and 15 were the most frequently altered (52% and 48% of cases, respectively), with all of their abnormalities corresponding to trisomies. The most frequent losses involved chromosomes 13 (26%) and X in females (32%). Other common numerical changes corresponded to chromosomes 1 (39%), 11 (37%), 6 (32%), 3 (31%), 18 (29%), 7 (28%), and 17 (22%). By contrast, chromosomes 8(13%), 10(8%), and 12(3%) were rarely altered. DNA aneuploidy by flow cytometry was detected in 67% of patients, and a high degree of correlation was observed between the DNA index obtained by flow cytometry and the chromosome index derived from fluorescence in situ hybridization studies, calculated according to two mathematical formulas (coefficient of correlation of 0.82 and 0.91 when at least 7 or 12 chromosomes were considered, respectively). The frequency of numeric chromosome aberrations was higher in those patients with progressive disease and, interestingly, trisomy of chromosome 8 was exclusively detected in this latter group of patients. Our study shows that, with the exception of chromosome 8, a possible marker of clonal evolution, the numeric chromosome changes are present in nearly all malignant plasma cells (r > 0.84). Finally, frequent associations between chromosomal aberrations were observed (ie, chromosomes 6, 7, 9, and 17; 7 and 15; and 11 and 17). By excluding them, it was found that two triple combinations of chromosome-specific probes, chromosomes 1 and 9 together with either chromosome 13 or 15, could be a useful marker for detection of residual disease, as it permits the identification of most MM patients displaying numerical changes.
    American Journal Of Pathology 08/1996; 149(1):153-61. · 4.89 Impact Factor
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    Article: Phenotypic changes in acute myeloid leukaemia: implications in the detection of minimal residual disease.
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    ABSTRACT: To explore the role of phenotypic changes as possible limiting factors in the immunological detection of minimal residual disease in patients with acute myeloid leukaemia (AML). 20 relapses were evaluated, with special attention to changes in the criteria used for the definition of a phenotype as "aberrant". In all cases the same monoclonal antibody and fluorochrome were used at diagnosis and in relapse. Six out of the 16 patients showed aberrant phenotypes at diagnosis. At relapse, no changes in the aberrant phenotypes were detected in most of the patients; nevertheless, in two of the four patients with asynchronous antigen expression this aberration disappeared at relapse. At diagnosis in both cases there were already small blast cell subpopulations showing the phenotype of leukaemic cells at relapse. Ten out of the 16 cases analysed showed significant changes in the expression of at least one of the markers analysed. At relapse in AML the "leukaemic phenotypes" usually remained unaltered, while other phenotypic features--not relevant for distinguishing leukaemic blast cells among normal progenitors--changed frequently; however, they were not a major limitation in the immunological detection of minimal residual disease.
    Journal of Clinical Pathology 02/1996; 49(1):15-8. · 2.31 Impact Factor
  • Article: Phenotypic analysis of CD34 subpopulations in normal human bone marrow and its application for the detection of minimal residual disease.
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    ABSTRACT: In the past, studies on CD34+ cells have been based on the use of monoclonal antibodies conjugated with different fluorochromes that show different fluorescence intensity and yield variable results. Moreover, most of these studies have neither specifically focused on adult human BM samples nor have they used combinations to explore specifically the phenotype of myeloid committed CD34+ cells. The aim of the present study has been to characterize the normal human CD34+ precursor cells from adult BM in order to identify missing or extremely rare phenotypes that can be used for detecting minimal residual disease (MRD) in patients with AML. For this purpose we have utilized the fluorochrome conjugates that provide the most sensitive signals for identifying low antigenic expression, and the technique has been adapted to the characterization of cells present at very low frequencies. Normal human BM samples from 13 adult healthy volunteers have been analyzed using triple stainings at flow cytometry. The mean percentage of CD34+ cells detected was 0.72 +/- 0.33%; these cells displayed an heterogeneous light-scatter distribution. Most CD34+ cells coexpressed CD38 (96.7 +/- 5.7%), HLADR (81.6 +/- 14.0%), CD33 (84.7 +/- 18.3%), CD13 (84.6 +/- 16.2%) and CD71 antigens (65.5 +/- 9.1%). In addition, almost half of CD34+ cells were CD117+ (60 +/- 26.8%). Only a small proportion of CD34+ cells coexpressed CD4 (15.5 +/- 11.7%, CD36 (31.7 +/- 6.2%), CD61 (16.3 +/- 12.9%), CD41 (6.5 +/- 5.5%) or the lymphoid associated markers CD10 (18.6 +/- 11.8%) and CD19 (12.3 +/- 13.2%). Reactivity for the CD15 antigen was observed in a small population of CD34+HLADR+ cells (11.6 +/- 11.2%) although its intensity of expression was lower than that of the more mature granulocytic cells. No CD34+ cells displayed CD14, CD65, CD20, strong CD22, CD3 and CD56 antigens. Accordingly, most adult bone marrow CD34+ cells appeared to be committed to the myeloid lineage (CD13+/CD33+) and displayed an intermediate-to-large FSC/SSC while the lymphoid-committed CD34+ cells (CD19+, CD10+) were in a minority with low FSC/SSC values. By triple marker stainings several phenotypes of CD34+ precursor cells were found to be either undetectable or present at very low frequencies (< 1 x 10(-3)) in the normal human adult bone marrow. These data may be of great value for defining leukemia 'associated' phenotypes used to detect minimal residual disease in adult acute leukemia patients.
    Leukemia 11/1995; 9(11):1896-901. · 9.56 Impact Factor
  • Article: Clinical, biological, and immunophenotypical characteristics of B-cell chronic lymphocytic leukemia with trisomy 12 by fluorescence in situ hybridization.
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    ABSTRACT: The clinical, biological, and immunophenotypical characteristics of B-cell chronic lymphocytic leukemia (B-CLL) patients with trisomy 12 detected by fluorescence in situ hybridization (FISH) using a chromosome 12 alpha-centromeric probe (D12Z3) were analyzed in the present study. From a total of 104 consecutive B-CLL patients, 21 (20%) displayed trisomy 12, the percentage of trisomic cells ranging from 13% to 76%. From the clinico-biological point of view, patients with trisomy 12 were associated with atypical CLL morphology (43% vs 10%, P = 0.04) and BM diffuse pattern (75% vs. 25%, P = 0.02) together with increased WBC counts (141 +/- 220 vs. 58 +/- 67 x 10(9)/L, P = 0.04). In contrast, no association was detected between the presence of trisomy 12 and other disease characteristics such as age, sex, clinical stage, hepatomegaly, lymphadenopathies, haemoglobin levels and platelet counts, and the cell cycle distribution of PB leukocytes in both groups of patients. Trisomy 12 patients had a significantly higher expression of the FMC7 antigen both in percentage (34 +/- 34% vs. 13 +/- 20%, P = 0.02) and absolute numbers (29 +/- 62 vs. 7 +/- 17 x 10(9)/L, P = 0.007). No major differences were found regarding the expression of mouse rosettes, CD19+, and CD19+/CD5+ lymphocytes. Upon analyzing the correlations between the disease characteristics of trisomy 12 cases, significant associations were found between the percentage of trisomic cells and both the WBC count (r = 0.52, P = 0.02) and the PB lymphocyte count (r = 0.60, P = 0.007).(ABSTRACT TRUNCATED AT 250 WORDS)
    Cytometry 10/1995; 22(3):217-22.
  • Article: Immunological detection of blast cell subpopulations in acute myeloblastic leukemia at diagnosis: implications for minimal residual disease studies.
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    ABSTRACT: The aim of the present study was to analyze the incidence of AML cases displaying more than one blast cell subpopulation by immunophenotype at diagnosis, since, any of them, although minimal, can be responsible for the relapse. For this purpose we have prospectively investigated the immunophenotype of blast cells from 40 de novo AML patients at diagnosis with a large panel of monoclonal antibodies in double and triple staining combinations analyzed at flow cytometry. The discrimination between the different cell populations was based on: (1) the existence of aberrant phenotypes; (2) differences in light-scatter characteristics; and (3) the expression of differentiation-associated antigens (CD34, CD117, HLADR, CD33, CD15, CD14, CD11b and CD4). More than one blast cell subpopulation was identified in 34 patients (85%), two subpopulations in 12 patients (30%), three in three cases (7.7%), four in 13 patients (32.5%) and five populations in six cases (15%). The most common criteria for discrimination of blast cell subpopulations was based on the expression of maturation-associated antigens and, interestingly, the blast subpopulations defined by higher reactivity for myeloid differentiation-associated markers had a more mature FSC/SSC pattern. In 53% of the patients at least one of the subpopulations identified was minimal (< 10% of the total leukemic cells). Regarding the existence of aberrant phenotypes three situations were observed: (1) none of the subpopulations had antigenic aberrations (10 cases); (2) coexistence of normal and aberrant subpopulations (five cases); and (3) all the subpopulations displayed aberrant phenotypes (19 cases). In 17 of the 23 patients (74%) who had two or more blast cell subpopulations with phenotypic aberrations, at least one aberrant criteria was common to all the subpopulations; this criteria by itself would permit the simultaneous identification of all subpopulations in minimal residual disease (MRD) studies. In the remaining cases the investigation of MRD should be based on the phenotypic characteristics of each subpopulation.
    Leukemia 07/1995; 9(6):993-8. · 9.56 Impact Factor
  • Article: Flow cytometry in the diagnosis of cancer.
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    ABSTRACT: Flow cytometry has rapidly expanded from basic research to clinical laboratories mainly due to its unique characteristics regarding cell analysis. Among the clinical uses of flow cytometry cancer represents one of the most relevant. Several applications of flow cytometry can currently be applied to the study of cancer, including the detection of tumour cell DNA aneuploidy, the analysis of tumour cell proliferation and the immunophenotyping of leukemias. Although standardized flow cytometry protocols for these applications are scanty, the clinical value has been clearly established. The presence of DNA aneuploidy and a high proportion of S-phase tumour cells have been associated with tumour malignancy and a poor prognosis. The immunophenotype of leukaemia is of great help both for the diagnosis and classification of chronic lymphoproliferative disorders and acute leukaemias, especially in acute lymphoblastic leukemia cases and the M0, M3-variant, M6 and M7 acute myeloblastic leukaemia subtypes. In addition, it allows the identification of relatively rare leukemia cases such as the biphenotypic and the Nk-cell lineage leukemias. The development of flow cytometry is continuously bringing new applications into the clinical laboratory in the area of cancer diagnosis.
    Scandinavian journal of clinical and laboratory investigation. Supplementum 02/1995; 221:145-52.
  • Article: The phenotype of L-CFU and its correlation with the immunological characteristics of the blast cell population in AML.
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    ABSTRACT: The membrane phenotype of AML clonogenic cells (L-CFU) was analyzed in 19 AML patients using an in vitro culture technique after a complement-mediated lysis assay employing a panel of six monoclonal antibodies (McAb) -HLA-DR, FMC56 (CD9), FMC27 (CD9), CD14, CD15, CD41a-. Our results show that L-CFU has a heterogeneous but immature phenotype lacking on the expression of differentiation antigens (CD14, CD15, CD41a). In addition, we observed that the L-CFU phenotype is different from that of the whole blast cell population. Interestingly, L-CFU showed a higher expression of HLA-DR antigens with respect to their progeny. Upon analyzing whether the L-CFU phenotype was related to both the morphological and immunological features of AML blast cells, it was observed that, while there is no correlation with the FAB classification, there was a partial relationship between the immunological phenotype of AML blast cells and that of L-CFU. Accordingly, the more immature AML cases showed a more differentiated L-CFU phenotype (HLA-DR+, CD9+, FMC27+) when compared with cases with a more mature blast cell phenotype. These results suggest that those AML cases with a relatively immature myeloblastic phenotype may arise from a progenitor cell that has undergone partial differentiation and that is unable to acquire myeloid differentiation antigens, while those AML cases with mature blast cells might emerge from a very early L-CFU that has the capacity to undergo a greater degree of differentiation.
    Annals of Hematology 06/1994; 68(5):233-6. · 2.62 Impact Factor
  • Article: Acute lymphoblastic leukemia (ALL): detection of minimal residual disease (MRD) at flow cytometry.
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    ABSTRACT: In the present study the usefulness of a method combining multiple staining direct immunofluorescence technique together with flow cytometry in order to predict relapse in ALL is analyzed in a group of 47 patients (11 T-ALL and 36 B-ALL). Results show that this method can be applied to at least two-thirds of all ALL patients being specially useful for the T-ALL cases (100% vs 56%) as this corresponding to the incidence of "aberrant" phenotypes. The detection of an increase in the percentage of bone marrow cells displaying "aberrant" phenotypes in two consecutive samples from the same patient is of great help on predicting relapse (sensitivity of 92% and specificity of 75%).
    Leukemia and Lymphoma 02/1994; 13 Suppl 1:87-90. · 2.58 Impact Factor

Institutions

  • 1994–2008
    • Universidad de Salamanca
      Salamanca, Castile and Leon, Spain
  • 1988–2007
    • Hospital Universitario de Salamanca
      Salamanca, Castile and Leon, Spain