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Introduction: Although B-cell acute lymphoblastic leukemia (B-cell ALL) survival rates have improved in recent years, Hispanic children continue to have poorer survival rates. There are few tools available to identify at the time of diagnosis whether the patient will respond to induction therapy. Our goal was to identify predictive biomarkers of treatment response, which could also serve as prognostic biomarkers of death, by identifying methylated and differentially expressed genes between patients with positive minimal residual disease (MRD+) and negative minimal residual disease (MRD-). Methods: DNA and RNA were extracted from tumor blasts separated by immunomagnetic columns. Illumina MethlationEPIC and mRNA sequencing assays were performed on 13 bone marrows from Hispanic children with B-cell ALL. Partek Flow was used for transcript mapping and quantification, followed by differential expression analysis using DEseq2. DNA methylation analyses were performed with Partek Genomic Suite and Genome Studio. Gene expression and differential methylation were compared between patients with MRD-/- and MRD+/+ at the end of induction chemotherapy. Overexpressed and hypomethylated genes were selected and validated by RT-qPCR in samples of an independent validation cohort. The predictive ability of the genes was assessed by logistic regression. Survival and Cox regression analyses were performed to determine the association of genes with death. Results: DAPK1, BOC, CNKSR3, MIR4435-2HG, CTHRC1, NPDC1, SLC45A3, ITGA6, and ASCL2 were overexpressed and hypomethylated in MRD+/+ patients. Overexpression was also validated by RT-qPCR. DAPK1, BOC, ASCL2, and CNKSR3 can predict refractoriness, but MIR4435-2HG is the best predictor. Additionally, higher expression of MIR4435-2HG increases the probability of non-response, death, and the risk of death. Finally, MIR4435-2HG overexpression, together with MRD+, are associated with poorer survival, and together with overexpression of DAPK1 and ASCL2, it could improve the risk classification of patients with normal karyotype. Conclusion: MIR4435-2HG is a potential predictive biomarker of treatment response and death in children with B-cell ALL.
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The main objective of the National Project for Research and Incidence of Childhood Leukemias is to reduce early mortality rates for these neoplasms in the vulnerable regions of Mexico. This project was conducted in the states of Oaxaca, Puebla, and Tlaxcala. A key strategy of the project is the implementation of an effective roadmap to ensure that leukemia patients are the target of maximum benefit of interdisciplinary collaboration between researchers, clinicians, surveyors, and laboratories. This strategy guarantees the comprehensive management of diagnosis and follow-up samples of pediatric patients with leukemia, centralizing, managing, and analyzing the information collected. Additionally, it allows for a precise diagnosis and monitoring of the disease through immunophenotype and measurable residual disease (MRD) studies, enhancing research and supporting informed clinical decisions for the first time in these regions through a population-based study. This initiative has significantly improved the diagnostic capacity of leukemia in girls, boys, and adolescents in the regions of Oaxaca, Puebla, and Tlaxcala, providing comprehensive, high-quality care with full coverage in the region. Likewise, it has strengthened collaboration between health institutions, researchers, and professionals in the sector, which contributes to reducing the impact of the disease on the community.
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INTRODUCTION: The expression pattern of CD27 and CD44 was found to correlate with the differentiation stages of B cell precursors, which were known to be involved in a variety of immunological responses. AIM OF THE STUDY: This study aimed to determine the biological significance of CD27 and CD44 expression in patients with B-precursor acute lymphoblastic leukemia (B-ALL), as well as their association with standard prognostic factors and therapeutic response. PATIENTS AND METHODS: This case-control study included 60 pediatric patients newly diagnosed with B-ALL and 30 pediatric controls. The patient CD27 and CD44 levels were measured using the Beckman Coulter Navios Flow Cytometer. RESULTS: Most malignant cells (91.6 %) expressed CD44, but only 50 % of the patients had CD27 expressed. The positive CD 44 expression was associated with unfavorable prognostic markers, including a decrease.
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OPINION STATEMENT: Treatment of chronic lymphocytic leukemia (CLL) has evolved dramatically during the last decade, from chemoimmunotherapy (CIT)-based therapies to newer B-cell receptor (BCR) signaling targeting agents, which are sometimes given as continuous schemes. Response to treatment was traditionally defined according to clinical variables designed to assign a response category. Interest in assessing for deeper responses in CLL by the means of measurable residual disease (MRD) testing has been the subject of research during the last several years. Analyses and sub-analyses of clinical trials have shown that achieving undetectable MRD (uMRD) in CLL is an important prognostic factor. In this review, we summarize the available evidence about MRD in CLL, from the various assays available for measurement, the compartment to test, the impact of reaching uMRD according to the treatment regimen, and the results of fixed duration treatment guided by MRD trials. Finally, we summarize how MRD can be incorporated in clinical practice and how it may guide fixed duration treatment in the future should evidence continue to accumulate in that direction.
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Leucemia Linfocítica Crônica de Células B , Humanos , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/etiologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Imunoterapia/métodos , Neoplasia Residual/diagnósticoRESUMO
Intensified pediatric chemotherapy regimens to treat adolescents and young adults (AYA) patients with Philadelphia negative acute lymphoblastic leukemia (ALL) have been associated with better outcomes. The local BFM 2009-based scheme complements the risk stratification assessing the measurable residual disease (MRD) along the induction phase with increasing levels of sensitivity. The present retrospective multicenter analysis included 171 AYA (15-40 years) patients treated accordingly between 2013 and 2019. Ninety-one percent obtained morphological complete remission, 67% a negative (<0.1%) MRD at day 33 (TP1), and 78% a negative (<0.01%) MRD at day 78 (TP2). The overall survival (OS) and the event-free survival (EFS) at 2 years were 62%±4.1 and 55%±4.1, respectively. The OS and EFS were significant better for prednisone responders, who achieved <10% BM blast at day 15, a negative MRD at TP1 or at TP2, and for low-risk patients. Age ≤30 years and WBC <30×109/L, particularly among B-phenotype, were also associated with longer OS. In the multivariable analyses, TP1 MRD positive (OS HR 2.8, 95% CI 1.4-5.7, p=0.004; EFS HR 3.0, 95% CI 1.6-5.7, p=0.001) and at TP2 (OS HR 2.6, 95% CI 1.3-5.3, p=0.012; EFS HR 2.6, 95% CI 1.3-5.1, p=0.006) were independently associated with earlier events. Age >30 years was also associated with a shorter survival (HR 3.1, 95% CI 1.3-7.5, p=0.014). Therefore, those 68 patients ≤30 years with TP1/TP2 negative MRD depicted a longer OS (2 years 85%±4.8). Based on our real-world data, the pediatric-based scheme is feasible in Argentina associated with better outcomes for younger AYA patients who achieved negative MRD at day 33 and 78.
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Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Prednisona/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Indução de Remissão , Risco , Estudos Retrospectivos , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/genética , Prognóstico , Intervalo Livre de Doença , Estudos Multicêntricos como AssuntoRESUMO
Introduction: The decisive key to disease-free survival in B-cell precursor acute lymphoblastic leukemia in children, is the combination of diagnostic timeliness and treatment efficacy, guided by accurate patient risk stratification. Implementation of standardized and high-precision diagnostic/prognostic systems is particularly important in the most marginalized geographic areas in Mexico, where high numbers of the pediatric population resides and the highest relapse and early death rates due to acute leukemias are recorded even in those cases diagnosed as standard risk. Methods: By using a multidimensional and integrated analysis of the immunophenotype of leukemic cells, the immunological context and the tumor microenvironment, this study aim to capture the snapshot of acute leukemia at disease debut of a cohort of Mexican children from vulnerable regions in Puebla, Oaxaca and Tlaxcala and its potential use in risk stratification. Results and discussion: Our findings highlight the existence of a distinct profile of ProB-ALL in children older than 10 years, which is associated with a six-fold increase in the risk of developing measurable residual disease (MRD). Along with the absence of CD34+ seminal cells for normal hematopoiesis, this ProB-ALL subtype exhibited several characteristics related to poor prognosis, including the high expression level of myeloid lineage markers such as MPO and CD33, as well as upregulation of CD19, CD34, CD24, CD20 and nuTdT. In contrast, it showed a trend towards decreased expression of CD9, CD81, CD123, CD13, CD15 and CD21. Of note, the mesenchymal stromal cell compartment constituting their leukemic niche in the bone marrow, displayed characteristics of potential suppressive microenvironment, such as the expression of Gal9 and IDO1, and the absence of the chemokine CXCL11. Accordingly, adaptive immunity components were poorly represented. Taken together, our results suggest, for the first time, that a biologically distinct subtype of ProB-ALL emerges in vulnerable adolescents, with a high risk of developing MRD. Rigorous research on potential enhancing factors, environmental or lifestyle, is crucial for its detection and prevention. The use of the reported profile for early risk stratification is suggested.
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Minimal Residual Disease (MRD) is the most important independent prognostic factor in acute lymphoblastic leukemia (ALL) and refers to the deep level of measurable disease in cases with complete remission by conventional pathologic analysis, especially by cytomorphology. MRD can be detected by multiparametric flow cytometry, molecular approaches such as quantitative polymerase chain reaction for immunoglobulin and T-cell receptor (IG/TR) gene rearrangements or fusion genes transcript, and high-throughput sequencing for IG/TR. Despite the proven clinical usefulness in detecting MRD, these methods have differences in sensitivity, specificity, applicability, turnaround time and cost. Knowing and understanding these differences, as well as the principles and limitations of each technology, is essential to laboratory standardization and correct interpretation of MRD results in line with treatment time points, therapeutic settings, and clinical trials. Here, we review the methodological approaches to measure MRD in ALL and discuss the advantages and limitations of the most commonly used techniques.
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Neoplasia Residual/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Animais , Linfócitos B/patologia , Citometria de Fluxo/métodos , Fusão Gênica , Rearranjo Gênico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Imunoglobulina G/genética , Neoplasia Residual/genética , Neoplasia Residual/patologia , Reação em Cadeia da Polimerase/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/patologiaRESUMO
Klebsiella pneumoniae é um patógeno oportunista, responsável por diversos tipos de infecções nosocomiais, e é considerado um microrganismo multirresistente. Dados na literatura que forneçam informações a respeito da resistência desse microrganismo a antimicrobianos em amostras de animais são escassos. Dessa forma, o objetivo deste trabalho foi avaliar o perfil e o seu aumento das resistências a antimicrobianos dentro da medicina veterinária. Um total de 67 isolados de K. pneumoniae, provenientes de diferentes sítios de isolamento de animais domésticos (39/67) e silvestres (28/67), foi confirmado por sequenciamento do gene 16S rRNA. O maior percentual de isolamento de K. pneumoniae foi de amostras de urina, com 16% (11/67), fezes, com 15% (10/67), e pulmão, com 13,5% (09/67). No perfil de resistência, foram testadas 11 categorias de antibióticos, sendo a maior taxa de resistência ao metronidazol 97% (65/67), à ampicilina 94% (63/67), à amoxicilina 93% (62/67), às sulfonamidas 93% (62/67), à colistina 93% (62/67) e à nitrofurantoína 88% (59/67). Aqueles que apresentaram menor taxa de resistência foram: meropenem 3% (2/67), imipenem 6% (4/67) e amicacina 16% (11/67). Todos os isolados foram considerados bactérias multirresistentes (MRD), com o índice de resistência múltipla aos antibióticos (IRMA) variando de 0,15 a 0,85 e com 60 tipos de padrões de resistência. O resultado deste estudo reforça que os animais são reservatórios de K. pneumoniae multirresistentes.(AU)
Klebsiella pneumoniae is an opportunistic pathogen responsible for several types of nosocomial infections and is considered a multiresistant microorganism. Data in the literature that provide information regarding the resistance of this microorganism to antimicrobials in animal samples are scarce. Thus, the objective of this work was to evaluate the profile and its increase of antimicrobial resistance within Veterinary Medicine. A total of 67 K. pneumoniae isolates from different domestic (39/67) and wild (28/67) isolation sites were confirmed by sequencing the 16S rRNA gene. The highest percentage of K. pneumoniae isolation was from urine samples with 16% (11/67), faeces 15% (10/67) and lung 13.5% (09/67). In the resistance profile, 11 categories of antibiotics were tested, with the highest resistance to metronidazole being 97% (65/67), ampicillin 94% (63/67), amoxicillin 93% (62/67), sulfonamides 93% (62 / 67), 93% colistin (62/67), and 88% nitrofurantoin (59/67). The ones with the lowest resistance were: meropenem 3% (2/67), imipenem 6% (4/67) and amikacin 16% (11/67). All isolates were considered multiresistant bacteria (MDR), with the Multiple Resistance to Antibiotics Index (IRMA) ranging from 0.15 to 0.85 and with 60 types of resistance patterns. The result of this study reinforces that the animals are reservoirs of multiresistant K. pneumoniae.(AU)
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Animais , Farmacorresistência Bacteriana , Klebsiella pneumoniae/isolamento & purificação , Animais Domésticos/microbiologia , Animais Selvagens/microbiologiaRESUMO
Klebsiella pneumoniae é um patógeno oportunista, responsável por diversos tipos de infecções nosocomiais, e é considerado um microrganismo multirresistente. Dados na literatura que forneçam informações a respeito da resistência desse microrganismo a antimicrobianos em amostras de animais são escassos. Dessa forma, o objetivo deste trabalho foi avaliar o perfil e o seu aumento das resistências a antimicrobianos dentro da medicina veterinária. Um total de 67 isolados de K. pneumoniae, provenientes de diferentes sítios de isolamento de animais domésticos (39/67) e silvestres (28/67), foi confirmado por sequenciamento do gene 16S rRNA. O maior percentual de isolamento de K. pneumoniae foi de amostras de urina, com 16% (11/67), fezes, com 15% (10/67), e pulmão, com 13,5% (09/67). No perfil de resistência, foram testadas 11 categorias de antibióticos, sendo a maior taxa de resistência ao metronidazol 97% (65/67), à ampicilina 94% (63/67), à amoxicilina 93% (62/67), às sulfonamidas 93% (62/67), à colistina 93% (62/67) e à nitrofurantoína 88% (59/67). Aqueles que apresentaram menor taxa de resistência foram: meropenem 3% (2/67), imipenem 6% (4/67) e amicacina 16% (11/67). Todos os isolados foram considerados bactérias multirresistentes (MRD), com o índice de resistência múltipla aos antibióticos (IRMA) variando de 0,15 a 0,85 e com 60 tipos de padrões de resistência. O resultado deste estudo reforça que os animais são reservatórios de K. pneumoniae multirresistentes.(AU)
Klebsiella pneumoniae is an opportunistic pathogen responsible for several types of nosocomial infections and is considered a multiresistant microorganism. Data in the literature that provide information regarding the resistance of this microorganism to antimicrobials in animal samples are scarce. Thus, the objective of this work was to evaluate the profile and its increase of antimicrobial resistance within Veterinary Medicine. A total of 67 K. pneumoniae isolates from different domestic (39/67) and wild (28/67) isolation sites were confirmed by sequencing the 16S rRNA gene. The highest percentage of K. pneumoniae isolation was from urine samples with 16% (11/67), faeces 15% (10/67) and lung 13.5% (09/67). In the resistance profile, 11 categories of antibiotics were tested, with the highest resistance to metronidazole being 97% (65/67), ampicillin 94% (63/67), amoxicillin 93% (62/67), sulfonamides 93% (62 / 67), 93% colistin (62/67), and 88% nitrofurantoin (59/67). The ones with the lowest resistance were: meropenem 3% (2/67), imipenem 6% (4/67) and amikacin 16% (11/67). All isolates were considered multiresistant bacteria (MDR), with the Multiple Resistance to Antibiotics Index (IRMA) ranging from 0.15 to 0.85 and with 60 types of resistance patterns. The result of this study reinforces that the animals are reservoirs of multiresistant K. pneumoniae.(AU)
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Animais , Farmacorresistência Bacteriana , Klebsiella pneumoniae/isolamento & purificação , Animais Domésticos/microbiologia , Animais Selvagens/microbiologiaRESUMO
PURPOSE OF REVIEW: The purpose of this review is to discuss the potential role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for Philadelphia-negative (Ph-) adult acute lymphoblastic leukemia (ALL) in first complete remission (CR1) in the era of minimal residual disease (MRD). RECENT FINDINGS: Allo-HSCT continues to have a role in the therapy of a selected group of high-risk adult patients with ALL in CR1. Although the clinical significance of MRD has been studied less extensively in adults with ALL than in children, recent studies support its role as the strongest prognostic factor that can identify patients that are unlikely to be cured by standard chemotherapy and benefit from undergoing allo-HSCT. In addition, MRD status both pre- and post-HSCT has been found to correlate directly with the risk of relapse. Currently, the clinical challenge consists on applying MRD and molecular failure to integrate novel agents and immunotherapy to lower MRD before allo-HSCT and to modulate the graft versus leukemia (GVL) effect after transplant.
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Transplante de Células-Tronco Hematopoéticas/métodos , Neoplasia Residual , Cromossomo Filadélfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adulto , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prognóstico , Indução de Remissão , Condicionamento Pré-Transplante , Transplante HomólogoRESUMO
OBJECTIVE: To compare the effect of 10% phenylephrine (PE) instillation and manual elevation (ME) on the upper eyelid position of the tested eye and the contralateral eye in patients with involutional blepharoptosis (IB). METHODS: IB patients were submitted to two tests followed by observation of the effect on the contralateral eyelid: (1) ME of the more ptotic eyelid; and (2) instillation of two drops of 10% PE (phenylephrine test) in the more ptotic eye. The patients were filmed before and 5, 10, and 15 minutes after instillation. The upper eyelid margin reflex distance (MRD1) was measured using the software Image J, and the results were analyzed with the linear mixed-effects model. RESULTS: The study included 70 patients aged 44-86 years, 64 of whom were female (91.43%), divided into three groups: subjects with unilateral IB, subjects with bilateral IB, and controls. The eye submitted to instillation with 10% PE displayed significant elevation during the first 10 min: from 1.33 ± 0.66 mm to 2.06 ± 0.89 mm (unilateral group), from 1.26 ± 0.63 mm to 2.29 ± 0.86 mm (bilateral group), and from 3.12 ± 0.68 mm to 4.06 ± 0.92 mm (control group). MRD1 decreased in the contralateral eye in IB patients, significantly more so after the phenylephrine test: PE vs. ME = 18.9% versus 17.2% reduction in the unilateral group, and 13.6% versus 10.7% reduction in the bilateral group. The outcome was not influenced by IB severity and the concurrence of IB and eye dominance. CONCLUSION: Both ME and 10% PE affected the contralateral upper eyelid, but the response was significantly better with the latter.
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Blefaroptose/terapia , Pálpebras , Fenilefrina/administração & dosagem , Agonistas de Receptores Adrenérgicos alfa 1/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Instilação de Medicamentos , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas/administração & dosagem , Estudos Retrospectivos , Resultado do TratamentoRESUMO
IGH gene rearrangement and IGK-Kde gene deletion can be used as molecular markers for the assessment of B lineage acute lymphoblastic leukemia (B-ALL). Minimal residual disease detected based on those markers is currently the most reliable prognosis factor in B-ALL. The aim of this study was to use clonal IGH/IGK-Kde gene rearrangements to confirm B-ALL diagnosis and to evaluate the treatment outcome of Tunisian leukemic patients by monitoring the minimal residual disease (MRD) after induction chemotherapy. Seventeen consecutive newly diagnosed B-ALL patients were investigated by multiplex PCR assay and real time quantitative PCR according to BIOMED 2 conditions. The vast majority of clonal VH-JH rearrangements included VH3 gene. For IGK deletion, clonal VK1f/6-Kde recombinations were mainly identified. These rearrangements were quantified to follow-up seven B-ALL after induction using patient-specific ASO. Four patients had an undetectable level of MRD with a sensitivity of up to 10-5. This molecular approach allowed identification of prognosis risk group and adequate therapeutic decision. The IGK-Kde and IGH gene rearrangements might be used for diagnosis and MRD monitoring of B-ALL, introduced for the first time in Tunisian laboratories.
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Humanos , Masculino , Feminino , Pré-Escolar , Adolescente , Pessoa de Meia-Idade , Biomarcadores Tumorais/genética , Rearranjo Gênico/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Non-Hodgkin lymphomas (NHL) are the most frequent hemato-oncological malignancies. Despite recent major advances in treatment, a substantial proportion of patients relapses highlighting the need for new therapeutic modalities. Promissory results obtained in pre-clinical studies are usually not translated when moving into clinical trials. Pre-clinical studies are mainly conducted in animals with high tumor burden; instead patients undergo chemotherapy as first line of treatment and most likely are under remission when immunotherapies are applied. Thus, an animal model that more closely resembles patients' conditions would be a valuable tool. METHODS: BALB/c mice were injected subcutaneously with A20 lymphoma cells and after tumor development different doses of chemotherapy were assessed to find optimal conditions for minimal residual disease (MRD) establishment. Tumor growth and survival, as well as drugs side effects, were all evaluated. Complete lymphoma remission was monitored in vivo using positron emission tomography (PET), and the results were correlated with histology. Immunological status was assessed by splenocytes proliferation assays in NHL-complete remission mice and by analyzing tumor cell infiltrates and chemokines/cytokines gene expression in the tumor microenvironment of animals with residual lymphoma. RESULTS: Two cycles of CHOP chemotherapy at days 25 and 35 post-tumor implantation induced complete remission for around 20 days. PET showed to be a suitable follow-up technique for MRD condition with 85.7 and 75% of sensibility and specificity respectively. Proliferative responses upon mitogen stimulation were similar in animals that received chemotherapy and wild type mice. Tumors from animals with residual lymphoma showed higher numbers of CD4+ and CD8+ and similar numbers of NK, neutrophils and Tregs infiltrating cells as compared with non-treated animals. Gene expression of several cytokines as well as an array of chemokines associated with migration of activated T cells to tumor sites was upregulated in the tumor microenvironment of animals that received chemotherapy treatment. CONCLUSIONS: We established a NHL-B pre-clinical model using standard chemotherapy to achieve MRD in immunocompetent animals. The MRD condition is maintained for approximately 20 days providing a therapeutic window of time where new immunotherapies can be tested in conditions closer to the clinics.
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Linfoma não Hodgkin/patologia , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proliferação de Células , Quimiocinas/genética , Quimiocinas/metabolismo , Modelos Animais de Doenças , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/genética , Linfoma não Hodgkin/imunologia , Camundongos Endogâmicos BALB C , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Padrões de Referência , Indução de Remissão , Baço/patologia , Análise de Sobrevida , Resultado do TratamentoRESUMO
Minimal residual disease is the most powerful predictor of outcome in acute leukemia and is useful in therapeutic stratification for acute lymphoblastic leukemia protocols. Nowadays, the most reliable methods for studying minimal residual disease in acute lymphoblastic leukemia are multiparametric flow cytometry and polymerase chain reaction. Both provide similar results at a minimal residual disease level of 0.01% of normal cells, that is, detection of one leukemic cell in up to 10,000 normal nucleated cells. Currently, therapeutic protocols establish the minimal residual disease threshold value at the most informative time points according to the appropriate methodology employed. The expertise of the laboratory in a cancer center or a cooperative group could be the most important factor in determining which method should be used. In Brazil, multiparametric flow cytometry laboratories are available in most leukemia treatment centers, but multiparametric flow cytometry processes must be standardized for minimal residual disease investigations in order to offer reliable and reproducible results that ensure quality in the clinical application of the method. The Minimal Residual Disease Working Group of the Brazilian Society of Bone Marrow Transplantation (SBTMO) was created with that aim. This paper presents recommendations for the detection of minimal residual disease in acute lymphoblastic leukemia based on the literature and expertise of the laboratories who participated in this consensus, including pre-analytical and analytical methods. This paper also recommends that both multiparametric flow cytometry and polymerase chain reaction are complementary methods, and so more laboratories with expertise in immunoglobulin/T cell receptor (Ig/TCR) gene assays are necessary in Brazil.
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Minimal residual disease is the most powerful predictor of outcome in acute leukemia and is useful in therapeutic stratification for acute lymphoblastic leukemia protocols. Nowadays, the most reliable methods for studying minimal residual disease in acute lymphoblastic leukemia are multiparametric flow cytometry and polymerase chain reaction. Both provide similar results at a minimal residual disease level of 0.01% of normal cells, that is, detection of one leukemic cell in up to 10,000 normal nucleated cells. Currently, therapeutic protocols establish the minimal residual disease threshold value at the most informative time points according to the appropriate methodology employed. The expertise of the laboratory in a cancer center or a cooperative group could be the most important factor in determining which method should be used. In Brazil, multiparametric flow cytometry laboratories are available in most leukemia treatment centers, but multiparametric flow cytometry processes must be standardized for minimal residual disease investigations in order to offer reliable and reproducible results that ensure quality in the clinical application of the method. The Minimal Residual Disease Working Group of the Brazilian Society of Bone Marrow Transplantation (SBTMO) was created with that aim. This paper presents recommendations for the detection of minimal residual disease in acute lymphoblastic leukemia based on the literature and expertise of the laboratories who participated in this consensus, including pre-analytical and analytical methods. This paper also recommends that both multiparametric flow cytometry and polymerase chain reaction are complementary methods, and so more laboratories with expertise in immunoglobulin/T cell receptor (Ig/TCR) gene assays are necessary in Brazil.