Detecção de doença residual mínima em crianças com leucemia linfoblástica aguda por citometria de fluxo

The detection of minimal residual disease (MRD) is an important prognostic factor in childhood acute lymphoblastic leukemia (ALL) providing crucial information on the response to treatment and risk of relapse. However, the high cost of these techniques restricts their use in countries with limited resources. Thus, we prospectively studied the use of flow cytometry (FC) with a simplified 3-color assay and a limited antibody panel to detect MRD in the bone marrow (BM) and peripheral blood (PB) of children with ALL. BM and PB samples from 40 children with ALL were analyzed on days (d) 14 and 28 during induction and in weeks 24-30 of maintenance therapy. Detectable MRD was defined as > 0.01% cells expressing the aberrant immunophenotype as characterized at diagnosis among total events in the sample. A total of 87% of the patients had an aberrant immunophenotype at diagnosis. On d14, 56% of the BM and 43% of the PB samples had detectable MRD. On d28, this decreased to 45% and 31%, respectively. The percentage of cells with the aberrant phenotype was similar in both BM and PB in T-ALL but about 10 times higher in the BM of patients with B-cell-precursor ALL. Moreover, MRD was detected in the BM of patients in complete morphological remission (44% on d14 and 39% on d28). MRD was not significantly associated to gender, age, initial white blood cell count or cell lineage. This FC assay is feasible, affordable and readily applicable to detect MRD in centers with limited resources.A detecção de doença residual mínima (DRM) é um importante fator prognóstico na leucemia linfóide aguda (LLA) infantil e fornece informações sobre a resposta ao tratamento e o risco de recaída. Entretanto, os altos custos das técnicas utilizadas limitam seu uso nos países em desenvolvimento. Desta forma, realizamos um estudo prospectivo para avaliar a citometria de fluxo (CF), utilizando três fluorescências e um painel limitado de anticorpos monoclonais, como método de detecção de DRM em medula óssea (MO) e sangue periférico (SP) de crianças com LLA. Amostras de MO e SP de 40 crianças portadoras de LLA foram analisadas nos dias (d)14 e d28 da indução e nas semanas 24-30 da terapia de manutenção. Foram consideradas como DRM+ as amostras que apresentaram > 0,01% das células com o fenótipo aberrante (FA). Oitenta e sete por cento dos pacientes apresentaram FA ao diagnóstico. No d14, 56% das amostras de MO e 43% do SP apresentaram DRM. No d28, foi detectada DRM em 45% e 31% das amostras de MO e SP, respectivamente. A porcentagem de DRM na MO foi similar à do SP nos casos de LLA-T, mas aproximadamente dez vezes maior na LLA de precursor-B. Foi detectada DRM na MO de 44% e 39% dos pacientes que estavam remissão morfológica nos d14 e d28, respectivamente. Não foi demonstrada associação significante entre a presença de DRM e sexo, idade, leucometria inicial e linhagem celular. Esta técnica de detecção de DRM por CF é relativamente barata e pode ser aplicada em centros com recursos limitados

Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma

Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers

シンガタ センダイ ウイルス ベクター オ モチイタ チンパンジー ケツエキ ユライ ノ ジンコウ タノウセイ カンサイボウ ノ サクセイ

熊本大