Decrease in Reduced-Form Albumin Among Chronic Kidney Disease Patients: New Insights in Cardiovascular Complications

From the perspective of free cysteine residue (Cys-34), human serum albumin (HSA) comprises a mixture of human mercaptoalbumin (HMA), in which the Cys-34 is not oxidized, human non-mercaptoalbumin (HNA)-1, which has a disulfide bond that can be reversibly oxidized, mainly by cysteine, and HNA-2, which is strongly oxidized to form sulfinic (-SO2H) or sulfonic (-SO3H) species. We have developed a convenient high-performance liquid chromatographic (HPLC) system for the clear separation of HSA into HMA, HNA-1 and HNA-2, and we have studied the dynamic changes of HSA-redox under various states of chronic kidney disease, in both a clinical and an experimental setting. In this article, we discuss the relationship between HSA-redox (especially the decrease of the reduced form), dialyzable uremic toxins and incident cardiovascular disease based on our recent investigations.