Comparison of microRNA expression in high-count monoclonal B-cell lymphocytosis and Binet A chronic lymphocytic leukemia

Abstract Background Evidence suggests that monoclonal B-cell lymphocytosis precedes all chronic lymphocytic leukemia cases, although the molecular mechanisms responsible for disease progression are not understood. Aberrant miRNA expression may contribute to the pathogenesis of chronic lymphocytic leukemia. The objective of this study was to compare miRNA expression profiles of patients with Binet A chronic lymphocytic leukemia with those of subjects with high-count monoclonal B-cell lymphocytosis and healthy volunteers (controls). Methods Twenty-one chronic lymphocytic leukemia patients, 12 subjects with monoclonal B-cell lymphocytosis and ten healthy volunteers were enrolled in this study. Flow cytometry CD19+CD5+-based cell sorting was performed for the chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis groups and CD19+ cells were sorted to analyze the control group. The expressions of miRNAs (miR-15a, miR-16-1, miR-29b, miR-34a, miR-181a, miR-181b and miR-155) were determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Results Significant differences between the expressions in the chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis groups were restricted to the expression of miR-155, which was higher in the former group. A comparison between healthy controls and monoclonal B-cell lymphocytosis/chronic lymphocytic leukemia patients revealed higher miR-155 and miR-34a levels and lower miR-15a, miR-16-1, miR-181a and miR-181b in the latter group. Conclusions Our results show a progressive increase of miR-155 expression from controls to monoclonal B-cell lymphocytosis to chronic lymphocytic leukemia. The role of miR-155 in the development of overt chronic lymphocytic leukemia in individuals with monoclonal B-cell lymphocytosis must be further analyzed.

Molecular and hematologic relapses in adult patients with acute promyelocytic leukemia: a cohort study

Abstract Objective: To evaluate factors predictive for relapse in a cohort of adult patients with acute promyelocytic leukemia monitored by molecular methods during consolidation and during at least one month of maintenance therapy. Methods: The charts and laboratory data of 65 adult patients with acute promyelocytic leukemia treated according to the International Consortium on Acute Promyelocytic Leukemia 2006 protocol were reviewed. The identification of the promyelocytic leukemia-retinoic acid receptor-alpha gene rearrangement at diagnosis, post-induction, post-consolidation and during maintenance treatment was performed by qualitative and quantitative reverse transcription polymerase chain reaction. Results: Eighty-nine patients were diagnosed with acute promyelocytic leukemia over a seven-year period and of these 65 were eligible for treatment with the protocol. Among the 45 patients who received consolidation and maintenance treatment, six (13%) relapsed, three of whom presented hematologic and three presented molecular relapse. The first relapses occurred at a median of 39 months. Relapsed patients were from all risk groups (low, intermediate and high) and both morphological types (M3 and M3variant) were found. Three of these patients are alive and in molecular remission after salvage treatment. There were no statistically significant differences regarding gender, age, risk group, morphology, promyelocytic leukemia breakpoint cluster region, use of all-trans retinoic acid, development of differentiation syndrome and number of days to complete remission between the patients who relapsed and those who did not. Conclusion: Our results reinforce the importance of prolonged monitoring of acute promyelocytic leukemia patients using molecular methods to detect relapse early.

Molecular basis for the diagnosis and treatment of acute promyelocytic leukemia

Acute promyelocytic leukemia is characterized by gene rearrangements that always involve the retinoic acid receptor alpha on chromosome 15. In the majority of patients t(15;17) is detected, which generates the promyelocytic leukemia gene/retinoic acid receptor alpha rearrangement. This rearrangement interacts with several proteins, including the native promyelocytic leukemia gene, thus causing its delocalization from the nuclear bodies, impairing its function. The immunofluorescence staining technique using the anti-PML antibody may be used to provide a rapid diagnosis and to immediately start therapy using all-trans retinoic acid. The experience of the International Consortium on Acute Promyelocytic Leukemia has demonstrated that early mortality was significantly reduced by adopting the immunofluorescence technique. All-trans retinoic acid combined with chemotherapy is the standard therapy; this promotes complete remission rates greater than 90% and cure rates of nearly 80%. However, early mortality is still an important limitation and hematologists must be aware of the importance of treating newly diagnosed acute promyelocytic leukemia as a medical emergency.

Do paradigma molecular ao impacto no prognóstico: uma visão da leucemia promielocítica aguda: [revisão] / From the molecular model to the impact on prognosis: an overview on acute promyelocytic leukemia: [review]

A leucemia promielocítica aguda (LPA) é um modelo da aplicabilidade clínica dos conhecimentos moleculares fisiopatológicos. Caracteriza-se por alterações genéticas recorrentes que envolvem o gene do receptor alfa do ácido retinóico. A conseqüência é uma proteína com sensibilidade reduzida ao ligante, com bloqueio da diferenciação mielóide. Entretanto, doses suprafisiológicas do ácido all-trans-retinóico (ATRA) são capazes de suplantar esta deficiência, e este é o princípio fundamental do tratamento da LPA, permitindo uma sobrevida livre de doença acima de 80 por cento quando adequadamente tratada. Epidemiologicamente, difere dos demais subtipos de leucemia mielóide aguda por apresentar incidência predominante em adultos jovens e, aparentemente, maior incidência em países de colonização "latina". Contrastando com os excelentes resultados observados em países desenvolvidos, a mortalidade por LPA no Brasil ainda é alta, apesar da ampla disponibilidade das medicações no país.

Acute promyelocytic leukemia (APL) is a model of clinical applicability of the knowledge of molecular physiopathology. It is characterized by recurrent genetic involvement of the retinoic acid alpha receptor. The consequence is a protein with low sensibility to its ligand and a myeloid maturation arrest. However, higher doses of all-trans-retinoic acid (ATRA) are able to supersede this deficiency and this is the mainstay of APL treatment leading to over 80 percent disease free survival, when adequately treated. Epidemiologically, it differs from other acute myeloid leukemia due to a higher incidence in young adults and in countries of "Latin" colonization. Differing from excellent results observed in developed countries, APL mortality in Brazil is still high, despite the wide availability of drugs.

Alta frequência de fatores de alto risco e de mortalidade precoce em pacientes brasileiros com leucemia promielocítica aguda / Increased frequency of high risk factors and elevated early mortality among Brazilian patients with acute promyelocytic leukemia

O tratamento da leucemia promielocítica aguda (LPA) com antrciclínicos e ácido trans-retinóico (ATRA) tem sido amplamente empregado e resultou em taxas de sobrevida a longo prazo de 80% a 90% em diferentes ensaios clínicos. A despeito da alta prevalência de LPA na América Latina, a efetividade de regimes de tratamento com ATRA e antraciclínicos não é conhecida. No Brasil, mais de 20% das leucemias mielóides agudas são do subtipo LPA. Neste estudo descrevemos uma análise retrospectiva de 157 pacientes brasileiros com LPA. Comparado com pacientes de países desenvolvidos, observamos uma alta prevalência de pacientes de alto risco e ma sobrevida e três anos de 49,9%. A taxa de mortalidade precoce foi de 28%, principalmente devido a sangramento (88,6%), com 45,2% dos pacientes apresentando evidências laboratoriais de coagulação intravascular disseminada ao diagnóstio. A despeito do fato de que nõ foram excluídos pacientes com base na idade ou no performance status, esta alta taxa de óbito mostra que é necessária uma melhora urgente no acesso dos pacientes a centros médicos especializados.

Therapy based on anthracyclines and all-trans-retinoic acid (ATRA) hás been widely used for acute promyelocytic leukemia (APL) and result in long term survival rates of 80% to 90% in different clinical trials. Despite the higher incidence of APL in Latin America, the effectiveness of ATRA + anthracyclines treatment is not known. In Brazil, more than 20% of acute myeloid leukemia are of the APL subtype. We describe a retrospective analysis including 157 Brazilian APL patients. Compared to developed countries, a higher incidence of higher incidence of high risk patients was observed and the overwall survival in three years was only 49.9%. Early mortality was 28%, mainly due to bleeding (88.6%), and laboratorial evidence of disseminated intravascular coagulation at diagnosis was present in 45.2% of the patients. Despite the fact that no patient was excluded based on age and performance status, the high death rates shows that urgent improvement in acess to specialized medical care is necessary in Brazil. Aiming to improve the outcome of APL patients in developing countries, the American Society of Hematology launched the International Consortium on APL, an educational iniative based on the use of an unified simplified treatment protocol, on line discussion tools and centralized laboratory diagnosis.

Características hematológicas e perfil de expressão de antígenos mielóides de pacientes com leucemia promielocítica aguda: análise de fatores prognósticos para o desenvolvimento da síndrome do ácido retinóico / Hematological features and expression profile of myeloid antigens of acute promyelocytic leukemia patients: analysis of prognostic factors for development of the retinoic acid syndrome

OBJETIVO: A leucemia promielocítica aguda (LPA) apresenta uma boa resposta ao tratamento com o ácido all trans retinóico (ATRA). Entretanto, alguns pacientes desenvolvem uma complicação grave chamada síndrome do ácido retinóico (SAR). O objetivo deste estudo foi comparar as características hematológicas e imunofenotípicas de pacientes com LPA que desenvolveram a SAR com as daqueles que não a desenvolveram. MÉTODOS: Foram analisados retrospectivamente os prontuários, exames radiológicos, lâminas de esfregaço de sangue e medula óssea de 71 pacientes com LPA, dos quais a análise imunofenotípica havia sido realizada em 56 casos. Foram identificados oito casos de SAR que, do ponto de vista clínico, caracterizaram-se por insuficiência respiratória (n=8), insuficiência renal (n=2), febre (n=5), ganho ponderal (n=3), edema periférico (n=3) e derrame pleural (n=5). As seguintes variáveis foram comparadas entre pacientes com e sem SAR: dosagem de hemoglobina, contagens de leucócitos e plaquetas no sangue periférico, distribuição dos subtipos hipergranular e variante, percentagens de blastos CD33+, CD13+, CD117+ na medula óssea, intensidade e variação dos valores de fluorescência destes antígenos nas células leucêmicas, expressas através dos canais medianos (CMFs) e dos coeficientes de variação (CVs) de fluorescência, respectivamente. RESULTADOS: A incidência da SAR foi de 11,26 por cento e o tempo médio para seu desenvolvimento 11,5 dias do início do tratamento. Todos os pacientes apresentaram desconforto respiratório agudo, por vezes associado à febre, ganho de peso, edema e insuficiência renal. Os achados radiológicos mais comuns foram: opacidades em vidro fosco, derrame pleural, espessamento peribrônquico e aumento da trama vascular pulmonar. Nenhuma das variáveis laboratoriais analisadas correlacionou-se significativamente ao risco de desenvolvimento da SAR, entretanto as Odd Ratios para CMF para o CD117 > 30 ua e CV para o CD33 < 50 foram de 7,14 (P=0,08) e de 7,86 (P=0,06), respectivamente. CONCLUSAO: A incidência e as características da SAR neste grupo de pacientes brasileiros foi semelhante à descrita na literatura. Nenhum dos parâmetros estudados correlacionou-se significativamente a um maior risco de desenvolvimento desta complicação.

Tratamento das infecções em pacientes com pancitopenia secundária e tratamento citorredutor / Treatment of infections in patients with pancytopenia resulting from cytoreductive treatment

Febre de etiologia desconhecida é a causa mais freqüente de internação hospitalar de pacientes neutropênicos em quimioterapia. O paciente é, em geral, oligossintomático, e a avaliação inicial deve incluir história e exames físicos completos e minuciosos, além de exames laboratoriais, procurando identificar a etiologia da febre e complicações decorrentes da quimioterapia. O tratamento com antibióticos de largo espectro deve ser iniciado prontamente, e o esquema terapêutico reavaliado 72 h, depois, com base nos estudos microbiológicos. No texto, discorremos sobre o diagnóstico da neutropenia febril, suas particularidades e o manejo do paciente

Quimiluminescencia em celulas blasticas leucemicas e sua aplicaçao no diagnostico diferencial de leucemias agudas / Chemiluminescence in leukemia blasts cells and it application in the differential diagnostic of acute leukemias

E descrito um metodo quimiluminescente simples e sensivel para a caracterizaçao da mieloperoxidase intracelular, utilizavel para a diferenciaçao entre blastos comprometidos com a linhagem mieloide e linfoide de paciente com leucemia aguda. Estabelecendo-se o ponto de "cut-off" em 13 mV de quimiluminescencia, todos os casos de leucemia mieloide aguda puderam ser diferenciados dos casos de leucemia linfoide aguda. A tecnica proposta demontrou a atividade peroxidasica inclusive em blastos do tipo MO e M7 (classificaçao FAB) os quais usualmente nao se coram nas preparaçoes citoquimicas classicas e requerem estudos com microscopia eletronica para a detecçao da mieloperoxidade

Efeitos adversos da transfusäo de hemoderivados / Adverse effects of blood transfusion

As transfusöes de hemoderivados apresentam um risco de 20por ciento de produzirem uma reaçäo adversa para o receptor. Entre estas reaçöes, as mais importantes säo a transmissäo de doenças como a hepatite e AIDS, as reaçöes transfusionais hemolíticas e a alossensibilizaçäo dos receptores. Nesta revisäo säo discutidas as principais reaçöes adversas às transfusöes sanguíneas e as medidas a serem tomadas para a sua prevençäo e tratamento.