Correlation between leukocyte membrane lipid peroxidation and expression of Cu/Zn-superoxide dismutase mRNA in hemodialysis patients

Hemodialysis raises oxidative stress through carbon-centered radicals despite improved biocompatibility

Leukocyte activation and the resulting oxidative stress induced by bioincompatible materials during hemodialysis impact the prognosis of patients. Despite multiple advances in hemodialysis dialyzers, the prognosis of hemodialysis patients with complications deeply related to oxidative stress, such as diabetes mellitus, remains poor. Thus, we re-evaluated the effects of hemodialysis on multiple reactive oxygen species using electron spin resonance-based methods for further improvement of biocompatibility in hemodialysis. We enrolled 31 patients in a stable condition undergoing hemodialysis using high-flux polysulfone dialyzers. The effects of hemodialysis on reactive oxygen species were evaluated by two methods: MULTIS, which evaluates serum scavenging activities against multiple hydrophilic reactive oxygen species, and i-STrap, which detects lipophilic carbon-center radicals. Similar to previous studies, we found that serum hydroxyl radical scavenging activity significantly improved after hemodialysis. Unlike previous studies, we discovered that scavenging activity against alkoxyl radical was significantly reduced after hemodialysis. Moreover, patients with diabetes mellitus showed a decrease in serum scavenging activity against alkyl peroxyl radicals and an increase in lipophilic carbon-center radicals after hemodialysis. These results suggest that despite extensive improvements in dialyzer membranes, the forms of reactive oxygen species that can be eliminated during dialysis are limited, and multiple reactive oxygen species still remain at increased levels during hemodialysis.

The impact of dialysis modality on novel markers of stress reaction, matrix remodeling and endothelial damage in children on chronic dialysis

BACKGROUND/AIMS

Dialysis triggers stress reaction, matrix remodeling and endothelial damage, but little is known about the changes it induces on selected heat shock proteins (Hsp90α), adhesion molecules (E-cadherin, sE-selectin), metalloproteinases (MMP-8) and their extracellular inducer (EMMPRIN). The aim of this study was to assess serum concentrations of the above-mentioned parameters in children on chronic dialysis.

METHODS

19 patients on hemodialysis (HD), 22 children on peritoneal dialysis (PD) and 30 age-matched controls were examined. Serum concentrations of parameters were assessed by ELISA.

RESULTS

Hsp90α, MMP-8, EMMPRIN and E-cadherin concentrations were significantly increased in children on dialysis vs. controls and higher levels were in HD than PD patients. There was no difference in the level of sE-selectin between HD and PD modalities. A single HD session diminished Hsp90α, MMP-8, EMMPRIN and E-cadherin values, but had no impact on sE-selectin levels.

CONCLUSIONS

Hemodialysis evokes stress reaction, matrix and endothelium destruction, to a greater extent than peritoneal dialysis. Single hemodialysis influences circulating cells rather than endothelial cells.