Effects of LDL‐immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemia

Abstract

Recently very potent extracorporeal cholesterol-lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (alpha- and gamma-tocopherol) and carotenoids (alpha- and beta-carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both alpha- and gamma-tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, alpha- and gamma-tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as beta-carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol-binding protein that are not removed during apheresis treatment.

Low‐Density Lipoprotein Apheresis Decreases Ferritin, Transferrin and Vitamin B12, Which May Cause Anemia in Serially Treated Patients

“…Comparable to the iron metabolism under LDL apheresis, data for vitamin B12 and folic acid concentrations under LDL apheresis are scarce. While removal of hydrophobic vitamin A and E by LDL apheresis has been described previously (16), we were able to demonstrate a significant decrease of vitamin B12 by LDL apheresis for the first time. A possible explanation could be the interaction of the cationic cyanocobalamin with the negatively charged heparin (HELP) or polyacrylamides (DALI), although this might be speculative and does not explain the decrease of vitamin B12 by the EC50‐filter in DFPP.…”

“…Since LDL apheresis is restricted to a small cohort of patients (2,3), the number of patients in this study was low, but within the range of previously published LDL apheresis studies (10,11,15,16). Despite the small number, the validity of our findings is supported by the overall decrease of transferrin and vitamin B12 in all patients, and of ferritin in 74% of the patients after one single LDL apheresis session.…”

The Effect of LDL-Apheresis and Rheohaemapheresis Treatment on Vitamin E

“…Vitamin E is also spontaneously transferred to apolipoprotein B-containing lipoproteins, including VLDL, LDL and HDL. Therefore, plasma tocopherols are distributed among these three lipoprotein types, with the more abundant LDL and HDL comprising the major carriers of vitamin E (24,26,27). For this reason, we investigated the levels of vitamin E in each lipoprotein fraction to more accurately assess pathophysiological processes.…”

Changes in serum afamin and vitamin E levels after selective LDL apheresis

“…11 Therefore during our studies we aimed to establish the levels and changes in these two molecules. In several previous studies serum vitamin E decreased significantly after LDL apheresis, [12][13][14] however, the main marker of antioxidant capacity, vitamin E/cholesterol ratio and vitamin E levels in erythrocytes significantly increased. 14 Human afamin is a serum glycoprotein, a member of the albumin gene family.…”

“…Therefore, to better understand how changes in afamin level may contribute to tocopherol level changes after LDL apheresis we investigated the serum levels of HDL, ApoA1, afamin, oxidized LDL, αand γ-tocopherol and the changes in HDL subfraction distributions in heterozygous FH patients before and after their first selective LDL apheresis treatment. We hypothesized that the reduction in αand γ-tocopherol after selective LDL treatment reported previously [12][13][14] might be caused by a reduction in afamin levels due to the absorption of afamin either directly or indirectly during the apheresis.…”