Granulopoietic precursors in chronic neutropenia.

11 patients with chronic neutropenia were evaluated. In 6 patients low numbers of CFU-DG were observed. Only 3 of these patients also had low CFU-C numbers, suggesting that these two precursors are not identical. Bone marrow samples from 2 patients were restudied a year later. The number of CFU-DG remained low while CFU-C numbers increased to control range in 1 patient. Studies for serum inhibitors were negative. No cytogenetic abnormalities were observed. This study suggests that abnormalities at different levels in the haemopoietic precursor cell hierarchy can be detected either simultaneously or independently in patients with chronic neutropenia.