Neutrophil kinetics in acute bacterial infection. A clinical study

Neutrophil kinetics in peripheral blood were studied with DF32P-labeled cells in eight patients during severe acute bacterial infection. Contrary to previous studies in man, the blood transit time of labeled neutrophils was short and the neutrophil turnover rate increased, up to ten times the normal, during the early phases of infection. This early phase was followed by a period in which the specific neutrophil radioactivity in the blood remained constant for up to 50 hours, probably indicating that in early convalescence neutrophil egress from the bone marrow to the blood is almost stopped. The demonstration of increased neutrophil turnover may seem to illustrate what might be considered an obvious fact, but is in contrast to previous findings and seems to obviate the prevailing theory of quantitatively unchanged but redistributed neutrophil kinetics during bacterial infection in man. The mechanism which apparently abruptly stops neutrophil egress from the bone marrow to the blood during early convalescence is unknown.