Alteration of Redox State of Human Serum Albumin before and after Hemodialysis

Abstract

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.

Improvement of the fraction of human mercaptalbumin on hemodialysis treatment using hydrogen-dissolved hemodialysis fluid: a prospective observational study

“…In the hemodialysis patients who have almost no renal function, it is thought that the albumin redox adjustment function is lowered during non-hemodialysis treatment. In the albumin redox of hemodialysis patients, the f(HMA) increased to nearly normal levels post-HD when hemodialysis treatment was performed, but decreased afterward , and was lower than for healthy persons before hemodialysis treatment [16]. The data of our study indicated similar results but the significant difference with healthy subjects was not only the f(HMA) of post-HD in EWHD2015, but the low numerical value.…”

Active Focal Segmental Glomerulosclerosis Is Associated with Massive Oxidation of Plasma Albumin

“…Overall, this reaction should involve 20 to 25% of albumin that is the amount of nonmercapto plus dimeric albumin in plasma. Even if in vitro studies furnish a solid chemical background to a participation of albumin into the antioxidant response in plasma, evidence that albumin oxidation takes place in vivo has never been reported, with the exception of scattered reports of partial albumin oxidation in ESRF (30) and diabetes that had been obtained with indirect techniques (31,32). Studies in patients with ESRF are of particular interest because they show the increase of nonmercaptoalbumin that should represent the product of reaction of free plasma thiols such as GSH and/or homocysteine with the sulfenic derivative of albumin.…”

“…Overall, the process of oxidation of albumin in FSGS seems substantially different from oxidation that is reported in patients with ESRF because, as already discussed, it mainly involves only the formation of an instable intermediate in this condition. According to the literature on the topic (31,32), the amount of sulfonic end product in patients with ESRF is approximately 5% of total albumin and is under the limit of sensitivity of the maleimide assay. Lack of observation of this peculiar structural modification on the basis of a direct spectroscopic approach in other cohorts of patients with primary and secondary glomerulonephritis with and without nephrotic syndrome and in young adults with ESRF suggests, therefore, a good degree of specificity for FSGS.…”

Role of Human Serum Albumin and Oxidative Stress in Diabetes

“…In constant, significant evidence for the presence of ROS-mediated protein damage in vivo and its possible clinical significance is not currently available. Many studies showed the presence of elevated levels of oxidized albumin, in patients with diabetes mellitus type 1 and type 2; aging [26], patients with chronic hepatitis C, oxidized albumin is a reliable marker of oxidative stress in hemodialysis patients [35,36] and alteration of redox state of HSA is also seen in patients under anesthesia and invasive surgery [37] and many other diseases. In diabetes the circulating albumin level is depressed.…”