ABSTRACT
BACKGROUND: By development of monoclonal antibodies (MoABs) directed against hematopoietic cells, flow cytometric analysis of bone marrow has become commonplace in clinical hematology laboratories and has a major role in evaluation of lymphohematopoietic malignancies. However, little information about antigen expressions and distribution of normal human bone marrow cells has been published. Therefore, we analysed the immunophenotype of the normal human bone marrow cells to get a normal baseline data for flow cytometric analysis. METHODS: The bone marrow aspirates of 20 healthy donors of allogeneic bone marrow transplantation were analysed using flow cytometry (Becton-Dickinson Co, USA). Seven gated region (R) were set using the forward vs. right angle light scatter (FSC/SSC) cytogram and the percentages of positive cells against 17 monoclonal antibodies were identified in these gated regions by dual parameter flow cytometry. RESULTS: The proportion of total CD45+ cells was 87.57+/-12.82% (mean+/-1SD, n=20) and CD45- (nucleated erythrocytes) cells was 12.43+/-12.82% of all nucleated bone marrow cells. T cells were more numerous than B cells in total gates (P=.0001). T helper/inducer cells (Th) to T suppressor/cytotoxic cells (Ts) ratio was 1.38+/-0.53 and CD4+ cells were distributed in larger size and higher SSC fractions in FSC/SSC cytogram than CD8+ cells (P=.0001). While CD4+, 8+ cells were rarely existed, CD10+ cells were 17.63+/-11.43% of all nucleated bone marrow cells and they mainly distributed in granulocytic fractions. Lymphocytes represent 60% of all lymphogate cells and T cells were mostly mature cells. CD10+ cells and CD34+ cells in the R1 (lymphogate) were 4.37+/-3.07% and 1.78+/-1.25%, respectively. The total CD34+ cells represent 0.88+/-0.5% of all nucleated bone marrow cells and 65% of them were CD34+CD33+ cells. CONCLUSION: These results indicate each subpopulation of normal bone marrow reveals different regional expression from morphological estimation and these normal expressions should be considered in flow cytometric analysis of hematologic disorders.