Discrepancies between serum and erythrocyte concentrations of vitamin E in hemodialysis patients: role of HDL-bound fraction of vitamin E

Recently, we have demonstrated that hemodialysis (HD) patients have higher serum and lower erythrocyte concentrations of vitamin E than controls. It is known that transfer of vitamin E from serum to erythrocyte is mostly due to high-density lipoproteins (HDL). For a better definition of the pattern of distribution of vitamin E in HD patients, we have dosed the amount of vitamin bound to serum HDL fraction. In 8 patients and in 8 healthy controls, we have determined the concentration of serum erythrocyte and HDL-bound vitamin E. The latest was obtained on an ultracentrifuged HDL fraction. HDL fractions from HD patients have been found to contain larger amounts of vitamin E than controls. The previously described higher serum and lower erythrocyte concentrations of vitamin E in HD patients have been confirmed in the study. The deficit of vitamin E in the membranes of erythrocytes from HD patients has been shown to be the result of increased consumption of the vitamin in the erythrocyte membranes, where it represents the major antioxidant agent. However, the finding of increased amounts of vitamin bound to HDL in HD patients suggests that the transfer of the vitamin to the erythrocyte membranes may also be defective.