Stem cell characterization of neutropenia: velocity sedimentation and mass culture analysis.

Human bone marrow obtained from patients with neutropenia contains a cell population which is absent or diminished in normal marrow. The abnormal population is composed of cells of volume 200-300 mum3 which sediment at 5-5 to 8-5 mm/h. Normal marrow contains one cell class giving rise to increased numbers of grnaulocyte colonies after mass culture, while marrow obtained from neutropenic patients, or from patients with marrow regeneration, shows two such populations; one of these cell classes corresponds to the abnormally large cells demonstrated on velocity sedimentation analysis. This population of large cells may represent a group of either self-renewing cells related to the committed granulocyte progenitors or the pluripotent stem cell.