Comparing low-density lipoprotein apheresis procedures: difficulties and remedies

Changes in HCV Viremia following LDL Apheresis in a HCV Positive Patient with Familial Hypercholesterolemia

It has been suggested that hepatitis C virus (HCV) can be associated with beta-lipoprotein in human serum. According to this, the LDL receptor could promote endocytosis of such a virus. In the present study, we evaluated the changes in HCV viremia in a HCV positive patient with familial hypercholesterolemia, undergoing both selective (DALI System, Fresenius) and non-selective (plasma exchange) LDL apheresis. HCV-RNA levels did not decrease following selective LDL apheresis, on the contrary showed a random, odd variation pattern (from –35% to +72%). Conversely, plasma exchange steadily induced a drop in HCV viremia (–35/43%), to a lower extent than that of a totally intravascular plasmaprotein, i.e., alpha 2-macroglobulin (–53/54%). These data indicate that beta-lipoprotein may not function as a plasma carrier of HCV, at least in the present case. Moreover, a continuous, quantitatively unforeseeable circulation of HCV virions from the intravascular plasma compartment to other extravascular and intracellular sites, seems to occurr during an apheresis session.

Lipid reductions by low-density lipoprotein apheresis: a comparison of three systems

There are currently three established low-density lipoprotein (LDL) apheresis systems: immunoadsorption, heparin-induced extracorporeal LDL precipitation (HELP), and dextran sulfate. We treated the same patient with all three systems and compared the lipid reductions achieved. A total of 135 consecutive treatments were studied, 57 with immunoadsorption, followed by 30 with HELP and 48 with dextran sulfate adsorption. The mean plasma volume (mean +/- SD) treated was 4.9 +/- 0.05, 3.08 +/- 0.091, and 3.39 +/- 0.71 L, respectively. The LDL-cholesterol (LDL-C) reduction was 75.5% +/- 7.4%, 61.6% +/- 5.1%, and 57.1% +/- 12.4%, respectively (P < .001 for immunoadsorption vHELP and dextran sulfate). The mean removal efficiency (mass removed/plasma volume treated) for LDL-C was 1.0 +/- 0.12, 1.42 +/- 0.25, and 1.15 +/- 0.21 g/L, respectively (P < .001 for HELP v immunoadsorption and dextran sulfate). The mean LDL-C plasma concentration before apheresis was 199 +/- 23.9, 201 +/- 25.7, and 186 +/- 28 mg/dL, respectively (P < .001 for dextran sulfate adsorption v immunoadsorption and HELP). Among the three LDL apheresis systems, immunoadsorption caused the greatest percent reduction in LDL-C, while HELP eliminated LDL-C from the plasma most efficiently. Dextran sulfate was similar to HELP in terms of LDL-C reduction, and its removal efficiency was similar to immunoadsorption. Dextran sulfate was also associated with the lowest pretreatment plasma LDL-C concentration.

Analysis of the long-term efficacy and selectivity of immunoadsorption columns for low density lipoprotein apheresis

Immunoadsorption low density lipoprotein (LDL) apheresis is performed with reusable columns containing anti-apolipoprotein B(ApoB) antibodies. We analyzed their long-term efficacy and selectivity. Performance over 60 treatment sessions of six pairs of immunoadsorption LDL apheresis columns was evaluated by analysis of variance using the removal of total cholesterol and ApoB to assess efficacy and the ratio of total cholesterol/high density cholesterol removed to assess selectivity. The removal of cholesterol did not vary significantly with treatment number. The mass of ApoB removed increased significantly (p = 0.002), and the mass of ApoB removed per volume unit of processed plasma showed a trend (p = 0.065) toward an increase with treatment number. Both parameters correlated with the serum ApoB concentration before treatment, which also increased significantly (p = 0.0007) with treatment number. No significant variation of selectivity was found. The efficacy of the LDL apheresis immunoadsorption columns did not decrease after 60 treatment sessions. The columns' selectivity also remained unchanged.