Production of Oxygen Free Radicals by Phagocytes in Patients on Hemodialysis

Abstract

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. There were no differences in the levels of opsonins, such as complements and immunoglobulins, between the patients and healthy adults. 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. 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. 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. In addition, the effect of three antibiotics, cefbuperazone, cefminox and latamoxef on luminol-enhanced CL of whole blood was studied in healthy 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.

Increased whole blood chemiluminescence in patients with chronic renal failure independent of hemodialysis treatment

“…Few data exist on the intensity of whole blood chemiluminescence in uremic patients and its changes during HD with cuprophane and other types of dialyzer [4,8,13,32,33,44]. In the majority of previous reports the possible association of blood chemiluminescence with circulatory anti-oxidants had not been analyzed [4,8,32,33,44].…”

“…In the majority of previous reports the possible association of blood chemiluminescence with circulatory anti-oxidants had not been analyzed [4,8,32,33,44]. Moreover, in five of these studies, only pCl was measured, while assessment of the total light emission (tCl), which reflects total ROS generation in a blood specimen, was omitted [8,13,32,33,44]. One study reported decreased fMLP-induced LBCL in uremic patients on HD [32].…”

“…Other authors, using a maximal dilution of 160 times in blood specimens, described decreased or normal pre-HD agonist-provoked LBCL (including fMLP-induced LBCL) [33] that did not change significantly at the end of HD [8,33]. Ueda [44] described increased agonist-induced LBCL in uremics, while Chen et al [5] found increased resting blood superoxide anion activity in uremics that was augmented by HD. The study protocol of Eckhardt et al [13] included blood specimens diluted 250 times from uremics and healthy controls.…”

“…Circulating phagocytes, especially polymorphonuclear leukocytes (PMNs), seem to be the most crucial sources of ROS in HD patients. However, conflicting research data demonstrate activation [4,45], lack of relevant changes [14,44], as well as inhibition of PMN respiratory burst [33,34,38] in uremia. Similarly, studies on the effect of HD on ROS generation by isolated PMNs have yielded conflicting results, with this function being reportedly suppressed [17,43], normal [28,33,42], or increased [4,14,20,28,33,36,42,46].…”