Hematopoietic stem cells transplantation and acute myeloid leukemia: Brazilian guidelines

The objective of this work was to define guidelines for the indication of hematopoietic stem cells transplantation (HSCT) in the treatment of acute myeloid leukemia (AML) in Brazil. The role of HSCT in the treatment of AML was discussed by the authors and presented to the Brazilian Society of Bone Marrow Transplantation in a meeting to formulate and ratify the Brazilian Guidelines on HSCT. This consensus was based on a review of international publications and on the Brazilian experience in HSCT for the treatment of AML. The optimal treatment for AML in first complete remission (1CR) has not been defined yet. There is consensus on the indication of allogeneic HSCT with myeloablative conditioning for patients who present high risk cytogenetic changes. Allogeneic HSCT is not indicated for low cytogenetic risk 1RC patients and, apparently, allogeneic and autologous HSCT and consolidation chemotherapy are similar for intermediate risk patients.O objetivo deste trabalho foi definir diretrizes para a indicação do transplante de células-tronco hematopoéticas (TCTH) no tratamento da leucemia mieloide aguda (LMA) no Brasil. O papel do TCTH no tratamento da LMA foi discutido pelosautores e apresentado para a Sociedade Brasileira de Transplante de Medula Óssea na reunião sobre Diretrizes Brasileiras para o TCTH, que o ratificou. Este consenso foi baseado na revisão da literatura internacional e na experiência brasileira em TCTH para o tratamento da LMA. O tratamento ideal para leucemia mieloide aguda em primeira remissão completa (1RC) ainda não está definido. Há consenso na indicação do TCTH alogênico, com condicionamento mieloablativo, para pacientes que apresentem alterações citogenéticas consideradas de alto risco. O TCTH alogênico não está indicado na 1RC para pacientes de baixo risco citogenético e, aparentemente, o TCTH alogênico, autólogo ou a quimioterapia de consolidação são equivalentes para os pacientes de risco intermediário.Hospital de Clínicas de Porto Alegre Serviço de Hematologia e Transplante de Medula ÓsseaUniversidade de São Paulo Hospital das Clínicas Centro de Transplante de Medula ÓsseaHospital de Câncer de Barret HemonúcleoUniversidade Federal de São Paulo (UNIFESP) Hospital Israelita Albert Einstein Centro de Transplante de Medula ÓsseaAssociação de Combate ao Câncer em Goiás Hospital Araújo Jorge Serviço de Transplante de Medula ÓsseaHospital Israelita Albert Einstein Programa de Hematologia e Transplante de Medula ÓsseaUNIFESP, Hospital Israelita Albert Einstein Centro de Transplante de Medula ÓsseaSciEL

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Acute graft versus host disease prediction based on gene expression profiling

Introdução: Transplante alogênico de células tronco hematopoéticas (TCTH) é uma importante terapia para doenças hematológicas, mas o sucesso de uma porção de transplantes é limitado pela doença do enxerto versus hospedeiro(GVHD). Os fatores de risco conhecidos para GVHD agudo (aGVHD) não fornecem uma estimativa precisa do risco individual e não auxiliam na individualização da terapia. Até o momento, não existe método diagnóstico que permita predizer aGVHD. A identificação de pacientes que desenvolverão aGVHD poderia permitir a individualização da terapia para uns e evitaria imunossupressão intensa para outros. Objetivos: Revelar um classificador molecular preditivo de aGVHD. Descobrir genes diferencialmente expressos e analisar eventos precoces que desencadeiam aGVHD. Explorar categorias funcionais e tipos celulares relacionados ao desenvolvimento de aGVHD. Casuística e métodos: Foram isolados, amplificados, marcados e co-hidridados com lâminas de microarray contendo 22.000 sondas, amostras de RNA mensageiro de 89 pacientes submetidos a TCTH HLA-idêntico mieloablativo ou de toxicidade reduzida, obtido de células mononucleares periféricas durante a enxertia medular. Os pacientes foram divididos em grupo treino e grupo teste, um modo utilizado para construir um modelo que discrimine pacientes com e sem aGVHD, e para testar o modelo em amostras independentes. Os genes informativos foram selecionados utilizando recursive feature elimination, seguido de sete diferentes algoritmos de classificação multivariados para estabelecer o classificador molecular no grupo treino. Os genes diferencialmente expressos entre amostras de pacientes com e sem GVHD foram submetidos a análise de enriquecimento das vias funcionais e agrupados de acordo com o perfil de expressão com células e tecidos através do SymAtlas. Resultados: Encontramos um classificador molecular composto de 233 genes nas amostras do grupo treino, que foram selecionados baseados na mais precisa classificação. No grupo teste da amostra, cerca de 80% dos pacientes puderam ser classificados. Para estes pacientes, o classificador mostrou uma acurácia preditiva de 75% (sensibilidade de 71% e especificidade de 78%). Analisando a anotação funcional dos genes diferencialmente expressos, observamos que em pacientes que desenvolveram aGVHD, houve aumento de expressao de genes da resposta antimicrobiana, transporte de gases, metabolismo de hemoglobina, além das alarminas. Nestas amostras também observamos a diminuição da expressão da IL1 e outros genes envolvidos na via do NF-kB. Vários genes super-expressos no periodo precoce do aGVHD foram associados a células precursoras. Conclusões: Nossos resultados mostram que um classificador molecular é capaz de identificar pacientes sob alto risco de desenvolver aGVHD. Estabelecer métodos de diagnóstico preditivo para aGVHD é o primeiro passo para a individualização da estratégia terapêutica após TCTH. Além disso, os resultados da análise de enriquecimento funcional e a expressão de genes em diferentes populações celulares, sugerem que eventos precoces envolvendo múltiplas populações de células precursoras possam predefinir a interação futura entre o enxerto em desenvolvimento e o paciente.Background: Allogeneic hematopoietic stem cell transplantation is an important last resort therapy for hematological diseases. Unfortunately, the success of a large proportion of these transplants is limited by graft-versus-host disease (GVHD). Currently known risk factors for acute GVHD (histoincompatibility, sex mismatch, older patients, previous pregnancies) do not provide a precise estimate of individual patient risk and do not help for individualization of the therapy. Early identification of those patients who will develop aGVHD may allow for individualized treatment, and also for the reduction of unnecessary treatment for those patients not at risk. Nowadays, however, there is no diagnostic method that allows prediction of aGVHD. Objectives: The goal of our study was to reveal a gene expression profile that would predict the occurrence of aGVHD. In addition, using enrichment of gene ontology categories, to analyze differentially expressed genes in order to better understand biology of the events preceding aGVHD. Material and methods: we collected blood samples from 89 recipients of myeloablative and reduced conditioning regimen HLA-identical sibling allogeneic hematopoietic stem cell transplants at the time of successful engraftment. We isolated total RNA from the peripheral blood mononuclear cells, amplified it, labeled, and co-hybridized to the microarray slides containing probes for 22,000 genes..The patients were divided into training and test groups, the former used to build a model discriminating patients with and without aGVHD and the latter - to test the model on independent samples. We selected the informative genes using “recursive feature elimination” method followed by seven different multivariate classification algorithms in order to establish a molecular classifier in the training set. Then we validated this new classifier in the test set of patients.. We found differentially expressed genes using T-test and accepted those with estimated false discovery rate below 10%. We have used Biobase Explain to find enrichment of functional groups among differentially expressed genes.Results: We found a molecular classifier comprised by 233 gene probes in the training set of samples which were selected based on the most accurate classification. In the test group of samples, we found that 80% of patients could be classified based on the concordance between classification methods as described above. For these patients, the classifier showed 75% of a predictive accuracy (71% of sensitivity and 78% of specificity). Analysis of functional annotations of differentially expressed genes showed that patients that developed acute GVHD have increased expression of antimicrobial genes, hemaglobin metabolism genes and alarmins. In these samples we also observed decreased expression of IL-1 and other genes involved in NF-kB activation. Several genes up-regulated before aGVHD were associated with multiple types of precursor cells. Conclusion: Our results show that molecular profiling is able to identify patients under high risk of acute GVHD at the time of engraftment. Establishing of a predictive diagnostic method for aGVHD is the first step of individualization of therapeutic strategy after hematopoetic stem cell transplantation. In addition, the results of functional enrichment analysis and expression in different cell populations suggest that early events during engrafment involving precursor cell populations might predefine results of interaction between stem cell allograft and patient body

Thymoma followed by aplastic anemia: two different responses to immunosuppressive therapy

Aplastic anemia is an uncommon complication of thymoma and is extremely infrequent after the surgical removal of a thymic tumor. Aplastic anemia is a result of marrow failure and is characterized by peripheral pancytopenia and severely depressed marrow cellularity; it may be an autoimmune manifestation of thymoma. As thymoma-associated hematological dyscrasias, which include pure red cell aplasia, aplastic anemia and myasthenia gravis, are supposed to be of immunologic origin, two cases of very severe aplastic anemia following the resection of lymphocytic thymomas treated with immunosuppression are herein presented

Chronic myeloid leukemia: A disease of youth in Brazil

UNIFESP (São Paulo Federal University)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo UNIFESP EPM, Disciplina Hematol & Hemoterapia, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Disciplina Hematol & Hemoterapia, BR-04023900 São Paulo, BrazilWeb of Scienc

Bone marrow transplantation and acute myeloid leukemia: Brazilian guidelines

Hospital de Clínicas de Porto AlegreUniversidade de São Paulo Faculdade de Medicina Hospital das ClínicasHospital de Câncer de BarretosUniversidade Federal de São Paulo (UNIFESP)Hospital Araújo JorgeHospital Israelita Albert EinsteinUNIFESPSciEL