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BACKGROUND: Measurable residual disease (MRD) assessed by multiparametric flow cytometry (MFC) has gained importance in clinical decision-making for acute myeloid leukemia (AML) patients. However, complying with the recent In Vitro Diagnostic Regulations (IVDR) in Europe and Food and Drug Administration (FDA) guidance in the United States requires rigorous validation prior to their use in investigational clinical trials and diagnostics. Validating AML MRD-MFC assays poses challenges due to the unique underlying disease biology and paucity of patient specimens. In this study, we describe an experimental framework for validation that meets regulatory expectations. METHODS: Our validation efforts focused on evaluating assay accuracy, analytical specificity, analytical and functional sensitivity (limit of blank (LoB), detection (LLoD) and quantitation (LLoQ)), precision, linearity, sample/reagent stability and establishing the assay background frequencies. RESULTS: Correlation between different MFC methods was highly significant (r = 0.99 for %blasts and r = 0.93 for %LAIPs). The analysis of LAIP specificity accurately discriminated from negative control cells. The assay demonstrated a LoB of 0.03, LLoD of 0.04, and LLoQ of 0.1%. Precision experiments yielded highly reproducible results (Coefficient of Variation <20%). Stability experiments demonstrated reliable measurement of samples up to 96 h from collection. Furthermore, the reference range of LAIP frequencies in non-AML patients was below 0.1%, ranging from 0.0% to 0.04%. CONCLUSION: In this manuscript, we present the validation of an AML MFC-MRD assay using BM/PB patient specimens, adhering to best practices. Our approach is expected to assist other laboratories in expediting their validation activities to fulfill recent health authority guidelines.
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Leucemia Mieloide Aguda , Humanos , Citometría de Flujo/métodos , Leucemia Mieloide Aguda/diagnóstico , Neoplasia Residual/diagnóstico , InmunofenotipificaciónRESUMEN
Current guidelines recommend flow cytometric analysis as part of the diagnostic assessment of patients with cytopenia suspected for myelodysplastic syndrome. Herein we describe the complete work-up of six cases using multimodal integrated diagnostics. Flow cytometry assessments are illustrated by plots from conventional and more recent analysis tools. The cases demonstrate the added value of flow cytometry in case of hypocellular, poor quality, or ambiguous bone marrow cytomorphology. Moreover, they demonstrate how immunophenotyping results support clinical decision-making in inconclusive and clinically 'difficult' cases.
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Síndromes Mielodisplásicos , Humanos , Citometría de Flujo/métodos , Síndromes Mielodisplásicos/diagnóstico , Médula Ósea , Células de la Médula Ósea , InmunofenotipificaciónRESUMEN
This article discusses the rationale for inclusion of flow cytometry (FCM) in the diagnostic investigation and evaluation of cytopenias of uncertain origin and suspected myelodysplastic syndromes (MDS) by the European LeukemiaNet international MDS Flow Working Group (ELN iMDS Flow WG). The WHO 2016 classification recognizes that FCM contributes to the diagnosis of MDS and may be useful for prognostication, prediction, and evaluation of response to therapy and follow-up of MDS patients.
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Síndromes Mielodisplásicos , Humanos , Citometría de Flujo , Síndromes Mielodisplásicos/diagnósticoRESUMEN
Given its myeloid-restricted expression, myeloperoxidase (MPO) is typically used for lineage assignment (myeloid vs. lymphoid) during acute leukaemia (AL) diagnostics. In the present study, a robust flow cytometric definition for MPO positivity was established based on the standardised EuroFlow protocols, the standardised Acute Leukaemia Orientation Tube and 1734 multicentre AL cases (with confirmed assay stability). The best diagnostic performance was achieved by defining MPO positivity as ≥20% of the AL cells exceeding a lymphocyte-based threshold. The methodology employed should be applicable to any form of standardised flow cytometry.
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Citometría de Flujo/normas , Inmunofenotipificación/normas , Leucemia , Proteínas de Neoplasias , Peroxidasa , Enfermedad Aguda , Femenino , Humanos , Leucemia/diagnóstico , Leucemia/enzimología , Leucemia/inmunología , Masculino , Proteínas de Neoplasias/sangre , Proteínas de Neoplasias/inmunología , Peroxidasa/sangre , Peroxidasa/inmunologíaRESUMEN
Flow-cytometric detection of now termed measurable residual disease (MRD) in acute myeloid leukemia (AML) has proven to have an independent prognostic impact. In a previous multicenter study we developed protocols to accurately define leukemia-associated immunophenotypes (LAIPs) at diagnosis. It has, however, not been demonstrated whether the use of the defined LAIPs in the same multicenter setting results in a high concordance between centers in MRD assessment. In the present paper we evaluated whether interpretation of list-mode data (LMD) files, obtained from MRD assessment of previously determined LAIPs during and after treatment, could reliably be performed in a multicenter setting. The percentage of MRD positive cells was simultaneously determined in totally 173 LMD files from 77 AML patients by six participating centers. The quantitative concordance between the six participating centers was meanly 84%, with slight variation of 75%-89%. In addition our data showed that the type and number of LAIPs were of influence on the performance outcome. The highest concordance was observed for LAIPs with cross-lineage expression, followed by LAIPs with an asynchronous antigen expression. Our results imply that immunophenotypic MRD assessment in AML will only be feasible when fully standardized methods are used for reliable multicenter assessment.
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Inmunofenotipificación , Leucemia Mieloide Aguda/diagnóstico , Neoplasia Residual/diagnóstico , Biomarcadores , Femenino , Citometría de Flujo/métodos , Humanos , Inmunofenotipificación/métodos , Masculino , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: While it is known that CD123 is normally strongly expressed on plasmacytoid dendritic cells and completely absent on nucleated red blood cells, detailed information regarding CD123 expression in acute leukemia is scarce and, if available, hard to compare due to different methodologies. METHODS: CD123 expression was evaluated using standardized EuroFlow immunophenotyping in 139 pediatric AML, 316 adult AML, 193 pediatric BCP-ALL, 69 adult BCP-ALL, 101 pediatric T-ALL, and 28 adult T-ALL patients. Paired diagnosis-relapse samples were available for 57 AML and 19 BCP-ALL patients. Leukemic stem cell (LSC) data was available for 32 pediatric AML patients. CD123 expression was evaluated based on mean fluorescence intensity, median fluorescence intensity, and percentage CD123 positive cells. RESULTS: EuroFlow panels were stable over time and between laboratories. CD123 was expressed in the majority of AML and BCP-ALL patients, but absent in most T-ALL patients. Within AML, CD123 expression was lower in erythroid/megakaryocytic leukemia, higher in NPM1 mutated and FLT3-ITD mutated leukemia, and comparable between LSC and leukemic blasts. Within BCP-ALL, CD123 expression was higher in patients with (high) hyperdiploid karyotypes and the BCR-ABL fusion gene. Interestingly, CD123 expression was increased in BCP-ALL relapses while highly variable in AML relapses (compared to CD123 expression at diagnosis). CONCLUSIONS: Authors evaluated CD123 expression in a large cohort of acute leukemia patients, based on standardized and reproducible methodology. Our results may facilitate stratification of patients most likely to respond to CD123 targeted therapies and serve as reference for CD123 expression (in health and disease). © 2018 The Authors. Cytometry Part B: Clinical Cytometry published by Wiley Periodicals, Inc. on behalf of International Clinical Cytometry Society.
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Subunidad alfa del Receptor de Interleucina-3/biosíntesis , Leucemia Mieloide Aguda/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Estudios de Cohortes , Citometría de Flujo , Humanos , Inmunofenotipificación , Subunidad alfa del Receptor de Interleucina-3/análisis , Subunidad alfa del Receptor de Interleucina-3/inmunología , Leucemia Mieloide Aguda/inmunología , Nucleofosmina , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/inmunologíaRESUMEN
BACKGROUND: A flow cytometry score (FCS) based on four parameters has been proposed for analysis of myelodysplastic syndromes patients with <5% blasts. We evaluated whether bone marrow aspirate samples isolated from femoral heads could be used for verification of cutoff values of the individual parameters score (IPS), contributing to the FCS and compared the applicability of FCS parameters in two centers. STUDY DESIGN AND METHODS: Bone marrow cells were obtained from femoral heads of patients who underwent hip replacement surgery. The score of the 4 individual parameters of the cell samples were obtained independently in two centers, using their own facilities and methods. Flow cytometry data files were subsequently exchanged and reanalyzed in the other center. The resulting four data sets were compared to assess reproducibility and outcomes in both centers. RESULTS: Twenty-nine of 40 bone marrow samples contained sufficient cells for analysis. Proposed cutoff values for 3 of 4 individual parameters were appropriate. All 29 samples showed a positive individual parameters score (IPS:1) in 1 of the 4 obtained data sets. Most differences in IPS scores were a result of reanalyzing the data file in the other center, rather than data acquisition. FCS: ≥2 were observed in 11 samples. CONCLUSION: Bone marrow samples from femoral heads are appropriate for verification of the proposed reference cutoff values of the individual parameters. Proposed reference cutoff values needed to be adjusted for reliable interpretation. Standardization of both data acquisition and data analysis is necessary for obtaining uniform results.
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Células de la Médula Ósea/metabolismo , Cabeza Femoral/metabolismo , Citometría de Flujo/métodos , Citometría de Flujo/normas , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/metabolismo , Anciano , Anciano de 80 o más Años , Células de la Médula Ósea/patología , Femenino , Cabeza Femoral/patología , Humanos , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/patologíaAsunto(s)
ADP-Ribosil Ciclasa 1/metabolismo , Leucemia/metabolismo , Linfoma/metabolismo , ADP-Ribosil Ciclasa 1/antagonistas & inhibidores , ADP-Ribosil Ciclasa 1/genética , Adolescente , Factores de Edad , Antineoplásicos Inmunológicos/uso terapéutico , Biomarcadores de Tumor , Niño , Preescolar , Expresión Génica , Humanos , Lactante , Leucemia/tratamiento farmacológico , Leucemia/genética , Linfoma/tratamiento farmacológico , Linfoma/genética , Terapia Molecular DirigidaAsunto(s)
ADP-Ribosil Ciclasa 1/sangre , Antígenos CD34/sangre , Leucemia Mieloide Aguda/sangre , Glicoproteínas de Membrana/sangre , Proteínas de Neoplasias/sangre , Células Madre Neoplásicas/metabolismo , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Leucemia Mieloide Aguda/patología , Masculino , Células Madre Neoplásicas/patología , Valor Predictivo de las Pruebas , RecurrenciaRESUMEN
Despite diagnostic criteria are currently available for the distinct subtypes of monocytic-lineage neoplasias, a number of partially overlapping features still remain evident, which may hamper their differential diagnosis. An accurate identification and characterization of monocytic cells is of major relevance for the diagnosis and classification of these neoplasias. In this regard, as compared to other conventional techniques, flow cytometry has shown the highest sensitivity for detection of early monocytic commitment of (normal and neoplastic) bone marrow CD34+ hematopoietic precursors as well as of monocytic aberrations and maturation blockades, which are frequently associated with clonal myeloid disorders. In the present paper we provide basic principles and criteria for multiparameter flow cytometry identification and characterization of bone marrow monocytic cells that contribute to an improved diagnostic and classification of monocytic lineage-associated acute leukemias in clinical settings, particularly when using the EuroFlow antibody panels. © 2015 International Clinical Cytometry Society.
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Citometría de Flujo/métodos , Leucemia Monocítica Aguda/diagnóstico , Monocitos/patología , Neoplasias/diagnóstico , Células de la Médula Ósea/patología , Diferenciación Celular/genética , Linaje de la Célula , Diagnóstico Diferencial , Células Madre Hematopoyéticas , Humanos , Leucemia Monocítica Aguda/sangre , Leucemia Monocítica Aguda/patología , Neoplasias/sangre , Neoplasias/patologíaRESUMEN
Flow cytometric analysis is a recommended tool in the diagnosis of myelodysplastic syndromes. Current flow cytometric approaches evaluate the (im)mature myelo-/monocytic lineage with a median sensitivity and specificity of ~71% and ~93%, respectively. We hypothesized that the addition of erythroid lineage analysis could increase the sensitivity of flow cytometry. Hereto, we validated the analysis of erythroid lineage parameters recommended by the International/European LeukemiaNet Working Group for Flow Cytometry in Myelodysplastic Syndromes, and incorporated this evaluation in currently applied flow cytometric models. One hundred and sixty-seven bone marrow aspirates were analyzed; 106 patients with myelodysplastic syndromes, and 61 cytopenic controls. There was a strong correlation between presence of erythroid aberrancies assessed by flow cytometry and the diagnosis of myelodysplastic syndromes when validating the previously described erythroid evaluation. Furthermore, addition of erythroid aberrancies to two different flow cytometric models led to an increased sensitivity in detecting myelodysplastic syndromes: from 74% to 86% for the addition to the diagnostic score designed by Ogata and colleagues, and from 69% to 80% for the addition to the integrated flow cytometric score for myelodysplastic syndromes, designed by our group. In both models the specificity was unaffected. The high sensitivity and specificity of flow cytometry in the detection of myelodysplastic syndromes illustrates the important value of flow cytometry in a standardized diagnostic approach. The trial is registered at www.trialregister.nl as NTR1825; EudraCT n.: 2008-002195-10.
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Linaje de la Célula , Células Eritroides/metabolismo , Citometría de Flujo , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Estudios de Casos y Controles , Femenino , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana EdadRESUMEN
A fully-standardized EuroFlow 8-color antibody panel and laboratory procedure was stepwise designed to measure minimal residual disease (MRD) in B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) patients with a sensitivity of ≤10-5, comparable to real-time quantitative polymerase chain reaction (RQ-PCR)-based MRD detection via antigen-receptor rearrangements. Leukocyte markers and the corresponding antibodies and fluorochromes were selected based on their contribution in separating BCP-ALL cells from normal/regenerating BCP cells in multidimensional principal component analyses. After 5 multicenter design-test-evaluate-redesign phases with a total of 319 BCP-ALL patients at diagnosis, two 8-color antibody tubes were selected, which allowed separation between normal and malignant BCP cells in 99% of studied patients. These 2 tubes were tested with a new erythrocyte bulk-lysis protocol allowing acquisition of high cell numbers in 377 bone marrow follow-up samples of 178 BCP-ALL patients. Comparison with RQ-PCR-based MRD data showed a clear positive relation between the percentage concordant cases and the number of cells acquired. For those samples with >4 million cells acquired, concordant results were obtained in 93% of samples. Most discordances were clarified upon high-throughput sequencing of antigen-receptor rearrangements and blind multicenter reanalysis of flow cytometric data, resulting in an unprecedented concordance of 98% (97% for samples with MRD < 0.01%). In conclusion, the fully standardized EuroFlow BCP-ALL MRD strategy is applicable in >98% of patients with sensitivities at least similar to RQ-PCR (≤10-5), if sufficient cells (>4 × 106, preferably more) are evaluated.
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Citometría de Flujo/métodos , Neoplasia Residual/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Citometría de Flujo/normas , Reordenamiento Génico , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Antígenos de Linfocitos B/genética , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Current recommendations for diagnosing myelodysplastic syndromes endorse flow cytometry as an informative tool. Most flow cytometry protocols focus on the analysis of progenitor cells and the evaluation of the maturing myelomonocytic lineage. However, one of the most frequently observed features of myelodysplastic syndromes is anemia, which may be associated with dyserythropoiesis. Therefore, analysis of changes in flow cytometry features of nucleated erythroid cells may complement current flow cytometry tools. The multicenter study within the IMDSFlow Working Group, reported herein, focused on defining flow cytometry parameters that enable discrimination of dyserythropoiesis associated with myelodysplastic syndromes from non-clonal cytopenias. Data from a learning cohort were compared between myelodysplasia and controls, and results were validated in a separate cohort. The learning cohort comprised 245 myelodysplasia cases, 290 pathological, and 142 normal controls; the validation cohort comprised 129 myelodysplasia cases, 153 pathological, and 49 normal controls. Multivariate logistic regression analysis performed in the learning cohort revealed that analysis of expression of CD36 and CD71 (expressed as coefficient of variation), in combination with CD71 fluorescence intensity and the percentage of CD117+ erythroid progenitors provided the best discrimination between myelodysplastic syndromes and non-clonal cytopenias (specificity 90%; 95% confidence interval: 84-94%). The high specificity of this marker set was confirmed in the validation cohort (92%; 95% confidence interval: 86-97%). This erythroid flow cytometry marker combination may improve the evaluation of cytopenic cases with suspected myelodysplasia, particularly when combined with flow cytometry assessment of the myelomonocytic lineage.
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Células Eritroides/metabolismo , Células Eritroides/patología , Síndromes Mielodisplásicos/metabolismo , Síndromes Mielodisplásicos/patología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Biomarcadores , Células de la Médula Ósea/metabolismo , Estudios de Casos y Controles , Femenino , Citometría de Flujo , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Refractory cytopenia of childhood is the most common type of childhood myelodysplastic syndrome. Because the majority of children with refractory cytopenia have a normal karyotype and a hypocellular bone marrow, differentiating refractory cytopenia from the immune-mediated bone marrow failure syndrome (very) severe aplastic anemia can be challenging. Flow cytometric immunophenotyping of bone marrow has been shown to be a valuable diagnostic tool in differentiating myelodysplastic syndrome from non-clonal cytopenias in adults. Here, we performed the first comprehensive flow cytometric analysis of immature myeloid, lymphoid cells and erythroid cells, and granulocytes, monocytes, and lymphoid cells in bone marrow obtained from a large prospective cohort of 81 children with refractory cytopenia. Children with refractory cyotopenia had a strongly reduced myeloid compartment, but not as severe as children with aplastic anemia. Furthermore, the number of flow cytometric abnormalities was significantly higher in children with refractory cytopenia than in healthy controls and in children with aplastic anemia, but lower than in advanced myelodysplastic syndrome. We conclude that flow cytometric immunophenotyping could be a relevant addition to histopathology in the diagnosis of refractory cytopenia of childhood. (The multi-center studies EWOG-MDS RC06 and EWOG-MDS 2006 are registered at clinicaltrials.gov identifiers 00499070 and 00662090, respectively).
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Anemia Aplásica/diagnóstico , Médula Ósea/inmunología , Inmunofenotipificación , Síndromes Mielodisplásicos/diagnóstico , Pancitopenia/diagnóstico , Adolescente , Anemia Aplásica/inmunología , Anemia Aplásica/patología , Antígenos CD/inmunología , Médula Ósea/patología , Niño , Preescolar , Diagnóstico Diferencial , Células Eritroides/inmunología , Células Eritroides/patología , Femenino , Citometría de Flujo , Granulocitos/inmunología , Granulocitos/patología , Humanos , Lactante , Linfocitos/inmunología , Linfocitos/patología , Monocitos/inmunología , Monocitos/patología , Síndromes Mielodisplásicos/inmunología , Síndromes Mielodisplásicos/patología , Pancitopenia/inmunología , Pancitopenia/patología , Índice de Severidad de la EnfermedadRESUMEN
B-cell precursors (BCP) regeneration in bone marrow (BM) after induction chemotherapy is prognostic for good treatment response in adult acute myeloid leukaemia (AML). We detected BCP regeneration in 81% of 59 paediatric AML patients at first complete remission; this compared to 46% in an adult study. BCP regeneration did not correlate with outcome or minimal residual disease levels. In 36 healthy BM controls, BCP levels were significantly higher in children as compared to adults. Therefore, BCP regeneration does not reflect good response to treatment in paediatric AML, possibly due to the relatively high base-line levels of BCP in children.
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Leucemia Mieloide Aguda/metabolismo , Células Precursoras de Linfocitos B/metabolismo , Adolescente , Adulto , Anciano , Células de la Médula Ósea/metabolismo , Estudios de Casos y Controles , Niño , Preescolar , Humanos , Inmunofenotipificación , Quimioterapia de Inducción , Lactante , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamiento farmacológico , Persona de Mediana Edad , Fenotipo , Pronóstico , Recurrencia , Resultado del Tratamiento , Adulto JovenRESUMEN
An international working group within the European LeukemiaNet gathered, aiming to determine the role of flow cytometry (FC) in myelodysplastic syndromes (MDS). It was agreed that FC has a substantial application in disease characterization, diagnosis and prognosis. FC may also be useful in predicting treatment responses and monitoring novel and standard therapeutic regimens. In this article the rationale is discussed that flow cytometry should be integrated as a part of diagnostic and prognostic scoring systems in MDS.
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Citometría de Flujo/métodos , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/terapia , Evaluación de Resultado en la Atención de Salud/métodos , Humanos , Agencias Internacionales , Síndromes Mielodisplásicos/clasificación , Pronóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sociedades CientíficasRESUMEN
Flow cytometry (FC) is recognized as an important tool in the diagnosis of myelodysplastic syndromes (MDS) especially when standard criteria fail. A working group within the Dutch Society of Cytometry aimed to implement FC in the diagnostic work-up of MDS. Hereto, guidelines for data acquisition, analysis and interpretation were formulated. Based on discussions on analyses of list mode data files and fresh MDS bone marrow samples and recent literature, the guidelines were modified. Over the years (2005-2011), the concordance between the participating centers increased indicating that the proposed guidelines contributed to a more objective, standardized FC analysis, thereby ratifying the implementation of FC in MDS.
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Citometría de Flujo/normas , Síndromes Mielodisplásicos/diagnóstico , Guías de Práctica Clínica como Asunto , Anciano , Anciano de 80 o más Años , Separación Celular/métodos , Separación Celular/normas , Femenino , Citometría de Flujo/métodos , Adhesión a Directriz , Humanos , Masculino , Países BajosRESUMEN
Gemtuzumab ozogamicin (GO) is a chemotherapy-conjugated anti-CD33 monoclonal antibody effective in some patients with acute myeloid leukemia (AML). The optimal treatment schedule and optimal timing of GO administration relative to other agents remains unknown. Conventional pharmacokinetic analysis has been of limited insight for the schedule optimization. We developed a mechanism-based mathematical model and employed it to analyze the time-course of free and GO-bound CD33 molecules on the lekemic blasts in individual AML patients treated with GO. We calculated expected intravascular drug exposure (I-AUC) as a surrogate marker for the response to the drug. A high CD33 production rate and low drug efflux were the most important determinants of high I-AUC, characterizing patients with favorable pharmacokinetic profile and, hence, improved response. I-AUC was insensitive to other studied parameters within biologically relevant ranges, including internalization rate and dissociation constant. Our computations suggested that even moderate blast burden reduction prior to drug administration enables lowering of GO doses without significantly compromising intracellular drug exposure. These findings indicate that GO may optimally be used after cyto-reductive chemotherapy, rather than before, or concomitantly with it, and that GO efficacy can be maintained by dose reduction to 6 mg/m(2) and a dosing interval of 7 days. Model predictions are validated by comparison with the results of EORTC-GIMEMA AML19 clinical trial, where two different GO schedules were administered. We suggest that incorporation of our results in clinical practice can serve identification of the subpopulation of elderly patients who can benefit most of the GO treatment and enable return of the currently suspended drug to clinic.
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Aminoglicósidos/farmacología , Anticuerpos Monoclonales Humanizados/farmacología , Modelos Teóricos , Aminoglicósidos/farmacocinética , Anticuerpos Monoclonales Humanizados/farmacocinética , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Antineoplásicos/farmacología , Línea Celular Tumoral , Gemtuzumab , Humanos , Leucemia Mieloide Aguda/metabolismo , Lectina 3 Similar a Ig de Unión al Ácido SiálicoRESUMEN
The myelodysplastic syndromes are a group of clonal hematopoietic stem cell diseases characterized by cytopenia(s), dysplasia in one or more cell lineages and increased risk of evolution to acute myeloid leukemia (AML). Recent advances in immunophenotyping of hematopoietic progenitor and maturing cells in dysplastic bone marrow point to a useful role for multiparameter flow cytometry (FCM) in the diagnosis and prognostication of myelodysplastic syndromes. In March 2008, representatives from 18 European institutes participated in a European LeukemiaNet (ELN) workshop held in Amsterdam as a first step towards standardization of FCM in myelodysplastic syndromes. Consensus was reached regarding standard methods for cell sampling, handling and processing. The group also defined minimal combinations of antibodies to analyze aberrant immunophenotypes and thus dysplasia. Examples are altered numbers of CD34(+) precursors, aberrant expression of markers on myeloblasts, maturing myeloid cells, monocytes or erythroid precursors and the expression of lineage infidelity markers. When applied in practice, aberrant FCM patterns correlate well with morphology, the subclassification of myelodysplastic syndromes, and prognostic scoring systems. However, the group also concluded that despite strong evidence for an impact of FCM in myelodysplastic syndromes, further (prospective) validation of markers and immunophenotypic patterns are required against control patient groups as well as further standardization in multi-center studies. Standardization of FCM in myelodysplastic syndromes may thus contribute to improved diagnosis and prognostication of myelodysplastic syndromes in the future.