Production of Oxygen Free Radicals by Phagocytes in Patients on Hemodialysis

In order to elucidate the vulnerability to infection in patients on chronic hemodialysis, as one of the host defense mechanisms, the production of oxygen free radicals by phagocytes was studied in patients by luminol-or lucigenine-enhanced chemiluminescence (CL). Whole blood CL of the patients, in both luminol-or lucigenine-enhanced was significantly higher than that in healthy adults after stimulation by zymosan, PMA, and Staphylococcus aureus (S. aureus) 209 P. However, the CL response of the patients' polymorphonuclear neutrophils (PMNs) with the same stimuli was slightly lower than that in healthy adults.<BR>There were no differences in the levels of opsonins, such as complements and immunogloblins, between the patients and healthy adults.<BR>It appears that any factor in the patients' serum enhances CL response, because of the PMN CL response after addition of patients' serum was higher than that after addition of healthy controls' serum, and the PMN CL response after the addition of patients' serum obtained after hemodialysis was higher than that before hemodialysis.<BR>The addition of erythrocytes to PMNs from healthy adults caused a reduction in the PMN CL response, but the addition of urea and creatinine had no effect.<BR>The CL response induced by microsphere-bound luminol (lumisphere), which makes possible the direct measurement of highly reactive oxygen within phagosomes, was studied in the patients and controls. The CL response in the patients was slightly lower than those in controls, but not significant. These results suggest that not only CL response of phagocytes but also other defense mechanisms should be studied further to make clear the vulnerability to infection in these patients.<BR>In addition, the effect of three antibiotics, cefbuperazone, cefminox and latamoxef on luminolenhanced CL of whole blood was studied in healty adults and the patients. After 3-hour exposure to those drugs at subinhibitory concentration (1/4 MIC), Klebsiella pneumoniae (K pneumoniae) 163 treated by drugs induced higher CL response of whole blood than that by untreated bacteria in both healthy adults and the patients, and the peak time of the CL response induced by the drug-treated bacteria was shorter than that by untreated bacteria. This study suggests that the three drugs at sub-MIC work in partnership with host defense against infection due to K pneumoniae even in patients on chronic hemodialysis.