Oscillations of granulocytic and megakaryocytic progenitor cell populations in cyclic neutropenia in man.

The concentration of granulocytic progenitor cells in the bone marrow of 2 patients with cyclic neutropenia was assessed at intervals during the cycle. Syncroneous oscillations were observed for cells forming neutrophilic and megakaryocytic colonies in diffusion chambers in vivo (CFU-D), suggesting a close relationship between the two cell types. However, an almost reverse relationship was observed between CFU-D and cells forming colonies in agar culture in vitro (CFU-C), which cycled out of phase with CFU-D. This supports the concept that CFU-D and CFU-C denote different cell types.