NEUTROPHILIC GRANULOCYTES IN ACUTE BACTERIAL-INFECTION - SEQUENTIAL STUDIES ON LYSZYME, MYELOPEROXIDASE AND LACTOFERRIN

Abstract

The changes in intraneutrophilic and plasma concentrations of the 3 antibacterial proteins lysozyme, lactoferrin and myeloperoxidase were studied sequentially during acute bacterial infection in 9 patients. Intraneutrophilic concentrations of the 3 proteins were decreased by more than 50% during the 1st wk of infection, followed by a slow increase over the following 2 wk. Nadir values coincided with maximal toxic granulation of the neutrophils. The data suggest that neutrophilic granulocytes are deficient during early bacterial infection, possibly because of deficient synthesis of antibacterial proteins in the bone marrow, and that neutrophil toxic granulation is the visual counterpart of this defect. The plasma concentrations of the 3 proteins showed considerable differences; although plasma lysozyme did not show any sequential changes, plasma myeloperoxidase was high at the start of infection and quickly decreased towards normal values, and plasma lactoferrin, high in the 1st samples, showed a secondary peak 1 wk after onset of disease, before normalization was seen. These differences may result from differences in the signals governing the release of the proteins from neutrophilic granulocytes, and it is suggested that these signals are specific for the individual antibacterial protein and not for the different types of neutrophil granules.