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Granulocyte function in patients with chronic renal failure: surface adherence, phagocytosis, and bactericidal
Abstract:
The defects in host defense mechanisms that explain the enhanced susceptibility to infection of patients with chronic renal failure are not understood, and previous studies concerning function of polymorphonuclear leukocytes (PMNL), the major antibacterial defense, conflict. Therefore, the antimicrobial functions of PMNL obtained from chronically uremic patients and serum factors essential for PMNL activity were evaluated. The potential modifying effect of high concentrations of serum from uremic patients on PMNL of uremic patients was determined, and granulocyte adherence, an activity related to recruitment of cells to inflammatory sites, was measured. Phagocytosis of 14C-labeled Staphylococcus aureus and bactericidal activity were normal and unaffected by high concentrations of uremic serum. Serum from uremic patients opsonized staphylococci and yeast normally. Oxidative metabolism of PMNL [14C-1]glucose oxidation, O2 consumption, and quantitative protein iodination) was normal, as was PMNL adherence. If the uremic patient has an increased risk of infection, this risk cannot be ascribed to defects of PMNL responses that have been studied in these patients.
Insights
Patients with chronic renal failure show normal polymorphonuclear leukocyte (PMNL) function, including phagocytosis and bactericidal activity. This suggests that increased infection risk in uremia is not due to PMNL defects.
Area of Science:
- Immunology
- Nephrology
- Infectious Disease
Background:
- Patients with chronic renal failure (CRF) exhibit increased susceptibility to infections.
- The underlying defects in host defense mechanisms contributing to this susceptibility remain unclear.
- Previous studies on polymorphonuclear leukocyte (PMNL) function in CRF have yielded conflicting results.
Purpose of the Study:
- To evaluate the antimicrobial functions of PMNL from chronically uremic patients.
- To assess the role of serum factors in PMNL activity in uremia.
- To determine the effect of uremic serum on PMNL function and adherence.
Main Methods:
- Assessed PMNL phagocytosis and bactericidal activity against Staphylococcus aureus.
- Measured PMNL oxidative metabolism (glucose oxidation, O2 consumption, protein iodination).
- Evaluated granulocyte adherence and serum opsonization of bacteria and yeast.
Main Results:
- PMNL phagocytosis and bactericidal activity were normal in uremic patients.
- Oxidative metabolism and adherence of PMNL were unaffected by uremic serum.
- Serum from uremic patients effectively opsonized staphylococci and yeast.
Conclusions:
- The studied PMNL functions (phagocytosis, bactericidal activity, oxidative metabolism, adherence) are not defective in patients with chronic renal failure.
- Increased infection risk in uremic patients cannot be attributed to the evaluated PMNL responses.
- Further research is needed to identify the specific host defense defects in chronic renal failure.