Thermofiltration in hypercholesterolemia treatment: analysis of removal and posttreatment cholesterol recovery

Low-density lipoprotein removal methods by membranes and future perspectives

Since the application by Thompson et al. in 1975 of plasma exchange for the treatment of 2 patients with familial hyperlipidemia, plasma purification techniques for selective low-density lipoprotein (LDL) removal (i.e., LDL apheresis) have been developed and adopted for the management of this disease. Thermofiltration is one of the LDL apheresis systems that utilizes membrane techniques developed by Nose and Malchesky's group in 1985. This article reviews its rationale, in vitro studies, animal studies, and clinical investigation. Thermofiltration effectively and selectively removes LDL cholesterol while retaining in the plasma physiologically important macromolecules such as albumin and high-density lipoprotein (HDL) cholesterol. Based on the global view of the treatment of atherosclerosis by LDL apheresis, membrane techniques are as effective, safe, and simpler to apply than other methods. Additionally, these methods are effective for the removal of lipoprotein (a) and fibrinogen; thus, they can address the needs in these application areas.

Assessment of currently available low-density lipoprotein apheresis systems

It has already been 10 years since the introduction of low-density lipoprotein (LDL) apheresis technologies. They have been established as technically and medically feasible for long-term treatment and economically acceptable, and their long-term treatment effects have been determined. Currently, there are efforts to develop more selective LDL removal systems. However, after 10 years of research, it is time to carefully review this strategy. The approach may have become too specific in light of the multiple macromolecules involved in the pathogenesis of atherosclerosis. In this paper, the six currently available LDL apheresis systems (plasma exchange, double filtration plasmapheresis, thermofiltration, LDL chemical adsorption (Kaneka system), LDL immunoadsorption, and the heparin-induced extracorporeal LDL precipitation [HELP] system) were reviewed and scored from various points of view such as effectiveness, simplicity, safety, and cost performance. Finally, each system was assessed from the global point of view in relation to the pathogenesis of lipid-related diseases.

Extracorporeal methods in lipid reduction pursuant to improvement in risk factors associated with atherosclerosis

Atherosclerosis is the leading cause of death in the United States. Elevated plasma levels of low-density lipoprotein and lipoprotein(a) [Lp(a)] and subnormal levels of high density lipoprotein are risk factors in atherosclerotic coronary heart disease. Extracorporeal methods of affecting these risk factors are reviewed. The limited information on the effects of apheresis procedures on Lp(a) is discussed and extended from a kinetic modeling approach. An estimate, made of the number of patients who could be expected to benefit from extracorporeal lipid lowering, is presented.