The importance of immunophenotyping by flow cytometry in distinction between hematogones and B lymphoblasts / A importância da imunofenotipagem por citometria de fluxo na distinção entre hematogônias e linfoblastos B

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.

Nature of leukemia-associated antigenicity of dinitrophenylated human lymphocytes and lymphoblasts.

Using dinitrophenylated human lymphocytes and phytohaemagglutinin–stimulated human lymphoblasts as antigens, antibodies were produced in rabbits. The immunological reactivities of the antisera so produced were tested against various types of leukemic cells after absorbing the sera with pooled normal leukocytes. Both the sera showed reactivity with all types of leukemic cells and no specific affinity for lymphoid leukemic cells was seen. This may suggest the presence of some common antigens on all types of leukemic cells or that dinitrophenylation brings about similar changes on all types of normal leukocytes.