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.

Monoclonal B-cell lymphocytosis in individuals from sporadic (non-familial) chronic lymphocytic leukemia families persists over time, but does not progress to chronic B-cell lymphoproliferative diseases

BACKGROUND: Monoclonal B-cell lymphocytosis is classified as 'high-count or clinical' monoclonal B-cell lymphocytosis and 'low-count or population' monoclonal B-cell lymphocytosis. Previously, 167 first-degree relatives pertaining to sporadic (non-familial) chronic lymphocytic leukemia families were studied and the presence of seven monoclonal B-cell lymphocytosis individuals was reported.OBJECTIVE: The aim of this report is to describe the outcomes of five of the original monoclonal B-cell lymphocytosis individuals.METHODS: Flow cytometry analysis was performed on mononuclear cells previously isolated from peripheral blood samples. A strategy of sequential gating designed to identify the population of CD19+/CD5+ B-lymphocytes was used and, subsequently, the monoclonal B-cell lymphocytosis cells were characterized by the CD20weak/CD79bweak/negative phenotype.RESULTS: The monoclonal B-cell lymphocytosis clone showed consistent stability over time with little variations in size. After a median follow-up of 7.6 years, none of the five monoclonal B-cell lymphocytosis individuals progressed to chronic lymphocytic leukemia or other B-cell lymphoproliferative disease.CONCLUSIONS: The data of this study suggest that chronic lymphocytic leukemia-like monoclonal B-cell lymphocytosis detected in the context of sporadic chronic lymphocytic leukemia families is not prone to clinical evolution and could be just a sign of immune senescence.

Pathologic rupture of the spleen in a patient with acute myelogenous leukemia and leukostasis

Rupture of the spleen can be classified as spontaneous, traumatic, or pathologic. Pathologic rupture has been reported in infectious diseases such as infectious mononucleosis, and hematologic malignancies such as acute and chronic leukemias. Splenomegaly is considered the most relevant factor that predisposes to splenic rupture. A 66-year-old man with acute myeloid leukemia evolved from an unclassified myeloproliferative neoplasm, complaining of fatigue and mild upper left abdominal pain. He was pale and presented fever and tachypnea. Laboratory analyses showed hemoglobin 8.3 g/dL, white blood cell count 278 × 109/L, platelet count 367 × 109/L, activated partial thromboplastin time (aPTT) ratio 2.10, and international normalized ratio (INR) 1.60. A blood smear showed 62% of myeloblasts. The immunophenotype of the blasts was positive for CD117, HLA-DR, CD13, CD56, CD64, CD11c and CD14. Lactate dehydrogenase was 2384 U/L and creatinine 2.4 mg/dL (normal range: 0.7-1.6 mg/dL). Two sessions of leukapheresis were performed. At the end of the second session, the patient presented hemodynamic instability that culminated in circulatory shock and death. The post-mortem examination revealed infiltration of the vessels of the lungs, heart, and liver, and massive infiltration of the spleen by leukemic blasts. Blood volume in the peritoneal cavity was 500 mL. Acute leukemia is a rare cause of splenic rupture. Male gender, old age and splenomegaly are factors associated with this condition. As the patient had leukostasis, we hypothesize that this, associated with other factors such as lung and heart leukemic infiltration, had a role in inducing splenic rupture. Finally, we do not believe that leukapheresis in itself contributed to splenic rupture, as it is essentially atraumatic...

Monoclonal B-cell lymphocytosis: a brief review for general clinicians / Linfocitose monoclonal de células B: uma breve revisão para clínicos gerais

Monoclonal B-cell lymphocytosis (MBL) is a recently described medical condition that displays biological similarities to the most common subtype of adult leukemia in the Western world, i.e. chronic lymphocytic leukemia (CLL). Diagnostic criteria have been published with the aim of differentiating between these two entities. The overall prevalence of MBL is at least 100 times higher than that of CLL, which indirectly suggests that MBL is not necessarily a pre-leukemic condition, although in some circumstances, CLL cases can really be preceded by MBL. In view of this high prevalence rate, general clinicians and even non-hematological specialists have a high chance of being faced with individuals with MBL in their routine clinical practice. MBL is classified as "clinical MBL", "population-screening MBL" and "atypical MBL" and the clinical management of affected individuals depends greatly on this differentiation. The present review provides a guide to diagnosing and following up MBL patients.

A linfocitose monoclonal de células B (LMB) é uma condição médica recentemente descrita que exibe similaridades biológicas com o mais comum subtipo de leucemia em adultos de países ocidentais, qual seja, a leucemia linfocítica crônica (LLC). Critérios diagnósticos foram publicados com o intuito de separar as duas entidades. A prevalência global da LMB é pelo menos 100 vezes maior do que a da LLC, o que, indiretamente, sugere que a LMB não é necessariamente uma condição pré-leucêmica, embora, em algumas circunstâncias, casos de LLC possam realmente ser precedidos pela LMB. Em virtude dessa alta taxa de prevalência, clínicos gerais e mesmo outros especialistas não hematologistas têm grande chance de deparar-se com casos de LMB em suas rotinas clínicas. A LMB é classificada como "LMB clínica", "LMB de screening populacional" e "LMB atípica", sendo que o manuseio clínico dos indivíduos afetados depende substancialmente dessa diferenciação. A presente revisão fornece um guia para o diagnóstico e acompanhamento dos pacientes com LMB.

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.

Neutrophil function in megaloblastic anemia

Chemotaxis, nitroblue tetrazolium (NBT) reduction and the presence of Fcy receptors on surface membranes were in the peripheral blood neutrophils of 20 patients with megaloblastic anemia (15 with folate deficiency and 5 with pernicious anemia). The percent of NBT - or Fcy - positive neutrophils was the same for patients and normal controls. In contrast, chemotaxis was decreased - 20% (P < 0.05) in megaloblastic anemia and when anemia was correcred in 3 cases, chemotaxis increased to levels within the normal range. In contrast to wath one would expect on the basis of these laboratory findings, there are no reports of increased susceptibility to infections in these patients

Benzenismo experimental / Experimental benzinism

Foram estudadas as alteraçöes do sangue periférico, medula óssea e baço de camundongos da raça suiça, que receberam injeçöes subcutâneas de 2 ml/kg de benzeno, 3 vezes por semana, em dias alternados, durante 20 semanas. A concentraçäo de hemoglobina, número de leucócitos, granulócitos e linfócitos dos animais tratados foram menores que os controles durante todo o experimento. A estimativa da celularidade da medula óssea näo mostrou diferenças significativas entre os 2 grupos. Apesar do peso do baço dos animais tratados com o benzeno näo diferir dos controles, existiam alteraçöes histológicas caracterizadas por diminuiçäo da celularidade da polpa vermelha e de megacariócitos

Ph1-negative chronic myelogenous leukemia with clonal chromosome abnormalities

Säo relatados os achados clínicos, hematológicos e citogenéticos de dois pacientes com síndromes mieloproliferativas Ph1-negativas. Um dos pacientes, um menino de 5 anos de idade com leucemia mielóide crônica "juvenil", exibia um cariótipo anormal 45,XO restrito a todas as células da medula óssea, enquanto outros tecidos somáticos tinham padräo normal 46,XY. A segunda paciente era portadora de uma forma atípica de leucemia mielóide crônica, acompanhada de eritrocitose e linfoadenopatia, mostrava um cariótipo 46,XX t(8;13) (p23;q14) em todas as células de medula óssea, baço e gânglios linfáticos, ao passo que eram normais os linfócitos do sangue periférico. Estes achados comprovam a natureza clonal da leucemia mielóide crônica Ph1-negativa, que compreenderia um grupo heterogêneo de doenças näo relacionadas com as formas típicas Ph1-positivas