Alteration of redox state of human serum albumin before and after hemodialysis

Background: Persistent hypoalbuminemia is a predictor of death in long-term maintenance hemodialysis patients, although cardiovascular diseases remain the leading cause of death. A decreased serum antioxidant activity in maintenance hemodialysis patients may contribute to increased oxidative damage, and may be associated with accelerated atherosclerotic changes. Methods: The aim of this study was to examine the redox state of human serum albumin in maintenance hemodialysis patients by high-performance liquid chromatography (HPLC) using a fluorescence detector. Results: HPLC of human serum albumin on a Shodex-Asahipak ES-502N column at pH 4.85 showed a clear resolution of human mercaptalbumin (HMA) and nonmercaptalbumin (HNA), which are the reduced and oxidized forms of human serum albumin, respectively. The mean +/- SD percentage of the HMA fraction of human serum albumin was significantly lower in maintenance hemodialysis patients than in age-matched normal subjects. The percentage of HMA increased 3 - 5 h after starting the hemodialysis and then decreased to subnormal levels. Conclusion: This suggests that serum albumin may be a major extracellular antioxidant in maintenance hemodialysis patients, and that hemodialysis may rescue serum albumin reduction by inducing intermolecular sulfhydryl-disulfide exchange reaction. Copyright (C) 2004 S. Karger AG, Basel.