Reliability of oxidative stress biomarkers in hemodialysis patients: a comparative study.
BACKGROUND
Oxidative stress (OS) is considered to play a major role in the development of end-stage renal disease (ESRD) complications. However, conflicting and inconsistent data have been reported on OS in ESRD patients. Our aim was to investigate the reliability of the most popular non-enzymatic plasma OS biomarkers in ESRD.


METHODS
Vitamins A (VitA), E and C (VitC), uric acid, plasma antioxidant and ferric-reducing potential (PAP and PRP), thiols (SH), malondialdehyde (MDA) and lipid hydroperoxides (HPO) were determined before and after dialysis in plasma from 33 ESRD patients on hemodialysis, hemodiafiltration or peritoneal dialysis and 20 control subjects.


RESULTS
In ESRD patients, high PRP and normal PAP values were positively correlated with VitC levels. After dialysis, PRP levels decreased, while unchanged PAP levels correlated positively with high VitA and transiently recovered SH values. All patients showed high levels of both MDA and cholesterol-normalized HPO. However, while the former significantly decreased after dialysis, the latter were unaffected by treatment. Paradoxical correlations of MDA with both VitA and HPO were found.


CONCLUSIONS
Plasma PRP and MDA levels may be dramatically affected by both uremia and dialysis; their use in ESRD patients may therefore lead to OS misevaluation and should be avoided. More reliable results can be obtained using physiologically relevant OS functional tests, such as PAP, and early biomarkers of OS damage, such as SH and HPO.
Palleschi
Simonetta
S
Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy. simonetta.palleschi@iss.it
De Angelis
Sandro
S
Diana
Loretta
L
Rossi
Barbara
B
Papa
Vincenza
V
Severini
Giancarlo
G
Splendiani
Giorgio
G
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers; D002624:Chemistry, Clinical / Q000379:methods*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000175:diagnosis*; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress; D006435:Renal Dialysis; D015203:Reproducibility of Results; D014511:Uremia / Q000150:complications
D000975:Antioxidants; D015415:Biomarkers; D008315:Malondialdehyde