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Incorporation of Low-Density Lipoprotein Apheresis into the Treatment Program
of Patients With Severe Hypercholesterolemia
Current Atherosclerosis Reports
2000;2:308-313.
Bruce R. Gordon, MD
At the time this article was written, there were several modes of LDL-apheresis
available:
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LDL-apheresis using columns containing antibodies or dextran sulfate cellulose:
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involves perfusion of plasma through a column containing poly- or monoclonal antibodies
to adsorb apolipoprotein-B–containing lipoproteins (apoB)
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regarding dextran sulfate cellulose, specific adsorption of apoB is achieved via
charge attraction of the matrix for the lipoprotein |
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LDL-apheresis using the heparin-induced method:
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positively charged LDL-C and other ß-lipoproteins bound by heparin at low
pH |
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specifically removes LDL-C, VLDL-C, Lp(a), and fibrinogen with little removal of
HDL-C or other plasma proteins |
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LDL-apheresis using double membrane filtration:
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selective process based on the ability of a secondary membrane to discriminate between
plasma LDL-C and Lp(a) and smaller molecules |
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LDL-apheresis using direct adsorption of lipoproteins blood perfusion system:
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negatively charged, immobilized, modified polyacrylate gel binds positively charged
apoB by electrostatic interaction |
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Lipoprotein(a) apheresis:
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immunoadsorption system that utilizes Lp(a)-specific antibodies |
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Observations of clinical improvement with minimal angiographic changes in patients
with atherosclerosis suggest that LDL-apheresis may have beneficial effects in addition
to lowering LDL-C. These effects may be due to improved blood rheology, improved
coronary microcirculation, lower oxidized LDL-C levels, removal of VLDL-C and down-regulation
of inflammatory processes.
The clinical benefits of LDL-apheresis have been demonstrated in numerous studies,
including the HELP LDL-Apheresis Multicenter Study, the LDL-Apheresis Atherosclerosis
Regression Study (LAARS), the German Multicenter LDL-Apheresis Trial, and the Familial
Hypercholesterolemia (FH) Regression Study. LAARS demonstrated that the addition
of biweekly LDL-apheresis to treatment with simvastatin improved regional myocardial
perfusion, myocardial ischemia, and peripheral vascular disease. LDL-apheresis has
been used to successfully treat hypercholesterolemic patients following heart transplant
and patients with elevated Lp(a) levels undergoing coronary angioplasty. Data from
the United States indicate that LDL-apheresis has decreased the number of clinical
events in patients with coronary heart disease (CHD) by 48%. This is substantiated
by a study in which the rate of coronary events in CHD patients with heterozygous
(hz) FH was decreased from 72% to 10% when LDL-apheresis was added to drug therapy.
Portocaval shunting has been used in some hmFH patients to obtain further reductions
in LDL-C. Furthermore, LDL-apheresis may provide an alternative to liver transplantation
in individuals with hmFH.
The author concludes that incorporating LDL-apheresis into treatment is beneficial
in patients with refractory hypercholesterolemia and CHD.
Click for full abstract.
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