Protein oxidative stress in dialysis patients.

Inflammatory status is observed in patients with chronic renal failure (CRF). The relationship between oxygen free radical production and dialysis could play an important role in protein oxidation. Carbonyl protein plasma level is an important tool in the study of protein stress, and it is related to the arterial intima thickness in the atherosclerosis process. We studied protein oxidative stress in 21 peritoneal dialysis (PD) patients and 42 hemodialysis (HD) patients as compared with 32 undialyzed patients with CRF. Carbonyl protein plasma levels were measured in nanomoles per milligram protein by the ELISA method (Winterbourn et al). Dialysis patients had a higher protein carbonyl content than did CRF patients (0.1265 +/- 0.04 nmol/mg vs. 0.1594 +/- 0.03 nmol/mg, p < 0.0002). Patients on PD had a lower level than patients on HD (0.1452 +/- 0.03 nmol/mg vs. 0.1665 +/- 0.04, p < 0.004). Glucose administration in PD is known to be able to increase glucose degradation products (GDPs) and advanced glycosylation end-products (AGEs) with high carboxylic and oxidative stress. In our study, the carbonyl protein level was higher in HD patients than in PD patients, perhaps because more protein oxidative stress is associated with hemodialysis technique or because the PD patients had greater residual renal function.