ABSTRACT
Hematogones are normal B-lineage lymphoid precursors in the bone marrow. B lymphoblasts are immature neoplastic cells present in patients with precursor B-cell acute lymphoblastic leukemia (B-ALL). Hematogones and B lymphoblasts share characteristics, such as morphological similarity often indistinct and expression of the same antigens in immunophenotypic analysis. Increased numbers of hematogones in patients with B-ALL during regeneration of bone marrow after treatment for leukemia, in cases of disease relapse or marrow transplantation, may be subject to questions about the nature and prognosis of this immature cell. This article presents information about the morphological and immunophenotypic characteristics of B lymphoid precursors and verifies the relevance of immunophenotyping by flow cytometry (FC) in the distinction between those cells. This differentiation is essential to establish a correct prognosis and assist in medical decision about the most appropriate therapeutic scheme.
As hematogônias são precursores normais de linhagem linfoide B da medula óssea. Os linfoblastos B representam células imaturas neoplásicas presentes em pacientes portadores de leucemia linfoblástica aguda de células precursoras B (LLA-B). As hematogônias e os linfoblastos B apresentam características comuns, como a semelhança morfológica muitas vezes indistinguível e a expressão dos mesmos antígenos na análise imunofenotípica. O aumento de hematogônias em pacientes de LLA-B durante a regeneração da medula após o tratamento para leucemia, em casos de recaída da doença ou transplante medular, pode ser objeto de questionamentos quanto à natureza e ao prognóstico desta célula imatura. Este artigo apresenta informações sobre as características morfológicas e imunofenotípicas dos precursores linfoides B e verifica a relevância da imunofenotipagem por citometria de fluxo na distinção entre essas células. Essa diferenciação é essencial para estabelecer um correto prognóstico e auxiliar na decisão médica sobre o esquema terapêutico mais adequado.
ABSTRACT
The activities of the enzymes NTPDase (EC 3.6.1.5, apyrase, CD39) and 5'-nucleotidase (EC 3.1.3.5, CD73) were analyzed in platelets from rats submitted to demyelination by ethidium bromide (EB) and treated with interferon beta (IFN-beta). The following groups were studied: I - control (saline), II - (saline and IFN-beta), III - (EB) and IV - (EB and IFN-beta). After 7, 15 and 30 days, the animals (n=7) were sacrificed and the platelets were separated by the method of Lunkes et al. [Lunkes, G., Lunkes D., Morsch, V., Mazzanti, C., Morsch, A., Miron, V., Schetinger, M.R.C., 2004. NTPDase and 5'-nucleotidase in rats alloxan- induced diabetes. Diabetes Research and Clinical Practice 65, 1-6]. NTPDase activity for ATP and ADP substrates was significantly lower in groups II and III after seven days, when compared to control (p<0.001). At fifteen days, ATP hydrolysis was significantly lower in group III and IV and higher in group II (p<0.001), while there was an activation of ADP hydrolysis in group II (p<0.001), when compared with the control. 5'-nucleotidase activity was significantly higher in group IV (p<0.001) after seven days, and lower in the groups III and IV (p<0.001) after fifteen days in relation to the control. No significant differences were observed in NTPDase and 5'-nucleotidase activities after thirty days. In conclusion, our study demonstrated that the hydrolysis of adenine nucleotides is modified in platelets of rats demyelinated and treated with IFN-beta.
