Flow cytometric analysis of human bone marrow. III. Neutrophil maturation.

Neutrophil maturation was studied in normal human bone marrow aspirates using multidimensional flow cytometry in comparison with morphology. The combination of the monoclonal antibodies, CD11b, CD15, and CD16, in addition to the forward and orthogonal light scattering signals permitted the isolation of neutrophilic cells from cells of other cell lineages with a purity of greater than 99%. An unexpectedly close relationship was found between the identification of neutrophil maturation by flow cytometry and morphological classification of cells sorted based on cell surface antigen expression and light scattering properties. The neutrophils could be divided into six distinct maturational stages, i.e., stage N I contained predominantly myeloblasts; stage N II, predominantly promyelocytes; stage N III, predominantly early myelocytes; stage N IV, predominantly myelocytes and metamyelocytes; stage N V, predominantly metamyelocytes and bands; and stage VI, predominantly segmented neutrophils. These data suggest that the morphologic changes during neutrophil maturation can be identified by flow cytometry using simultaneous quantitative assessment of multiple antigens in concordance with the light scattering properties of the human bone marrow cells.