Therapeutic efficiency of lipoprotein(a) reduction by low-density lipoprotein immunoapheresis

Differences in the atherogenic risk of patients treated by lipoprotein apheresis according to their lipid pattern

In high-risk patients who are already on a maximal lipid-lowering therapy, a lipoprotein apheresis is an important therapeutic option in preventing further progress of vascular complications as it may decrease both LDL-cholesterol (LDL-C) and lipoprotein(a) (Lp(a)) levels. We looked at the occurrence of cardiovascular events before apheresis and during apheresis in three groups defined by their lipid patterns at the start of an apheresis treatment: Group 1 (LDL-C ≥ 3.4 mmol/l and Lp(a) ≤ 600 mg/l; n = 35), Group 2 (LDL-C ≤ 3.4 mmol/l and Lp(a) ≥ 600 mg/l n = 37) and Group 3 (LDL-C ≥ 3.4 mmol/l and Lp(a) ≥ 600 mg/l; n = 15). Group 2 shows a time period of about 10 years from the first event until the start of apheresis treatment (compared to 2-6 years in the other two groups). Before the start of apheresis treatment 2.1 events per patient had occurred in Group 1, 3.4 events per patient in Group 2 and 1.8 events per patient in Group 3. Under apheresis therapy just 0.9 events per patient occurred in Group 1, 0.5 in Group 2 and 0.5 in Group 3. When comparing the two years before the start of apheresis treatment with the first two years under apheresis we saw the following reduction rates of cardiovascular events: Group 1-54%; Group 2-83%; Group 3-83.5%. Our results show that the reduction of cardiovascular events due to lipoprotein apheresis is especially high in patients with elevated levels of Lp(a) compared to patients with elevated LDL-C only indicating that physicians should be more focused on the risk factor elevated Lp(a).

Lipidfiltration--safe and effective methodology to perform lipid-apheresis

Familial hypercholesterolemia (FH) not adequately responding to diet and drug therapy represents an indication for extracorporeal lipid-apheresis, which has become an highly effective and approved therapy for those patients in several countries. Based on different methodology, five treatment options of lipid-apheresis exist and are in widespread practical use covered by regular reimbursement in Germany. All methods are safe and demonstrate equivalent efficacy of reducing LDL cholesterol with respect to the single apheresis session as well as during long-term treatment. Therefore German reimbursement guidelines leave the choice of the method to the discretion of the apheresis center. Related to properties of the used technology all methods exhibit characteristic patterns of additional plasma protein elimination, which do not impair, but in part may increase the therapeutic benefit of lipid-apheresis. Fibrinogen reduction has to be mentioned as an example. The Lipidfiltration system is based on plasmafiltration previously referred to as membrane differential filtration (MDF), synonymous with double filtration plasmapheresis (DFPP). The new term Lipidfiltration was the result of technological progress in the manufacturing process of the plasmafilter resulting in enhanced sieving characteristics and capacity. The Lipidfiltration system is completed by a specifically designed therapy machine with optimised performance characteristics.

From membrane differential filtration to lipidfiltration: technological progress in low-density lipoprotein apheresis

Extracorporeal low-density lipoprotein (LDL) apheresis is an established and highly effective therapy for patients with familial hypercholesterolemia (FH) not adequately responding to diet and drug therapy alone. Based on different methodology, five treatment options of LDL apheresis are available and in widespread practical use in Germany. All methods are safe and demonstrate equivalent efficacy of reducing LDL cholesterol with respect to the single apheresis session as well as during long-term treatment. Owing to methodological properties all methods also exhibit characteristics of additional plasma protein elimination, which do not impair, but in part, increase the beneficial therapeutic effect of LDL apheresis. Fibrinogen reduction has to be mentioned as an example. The lipidfiltration system is based on plasmafiltration previously named membrane differential filtration (MDF), synonymous with double filtration plasmapheresis (DFPP). The new term lipidfiltration was the result of technological progress leading to a significant improvement of the efficiency. The system consists of a novel lipid filter with enhanced sieving characteristics and capacity, and is completed by an enhanced therapy machine with an optimized heating unit.

Atorvastatin improves blood rheology in patients with familial hypercholesterolemia (FH) on long-term LDL apheresis treatment

To determine the effect of atorvastatin on blood rheology in patients with familial hypercholesterolemia (FH) on regular LDL apheresis, we prospectively studied the rheological variables fibrinogen, plasma viscosity, red cell aggregation, whole blood viscosity, hematocrit and platelet aggregation in 12 patients (two homozygous, ten heterozygous) before and during treatment with atorvastatin. Baseline values of red cell aggregation and whole blood viscosity were increased in FH patients on regular LDL apheresis compared with healthy controls (P<0.05), whereas fibrinogen, plasma viscosity and hematocrit were similar in the two groups. Treatment with atorvastatin reduced red cell aggregation (P<0.01), whole blood viscosity (P<0.01), plasma viscosity (P<0.01) and platelet aggregation (P<0.05), but caused a slight increase in plasma fibrinogen (by 5%; P<0.01). Our findings suggest that atorvastatin improves blood rheology in patients with FH on regular LDL-apheresis. This improvement in blood flow properties may contribute to the well-known beneficial effects of atorvastatin on cardiovascular risk in patients with severe hyperlipidemia and atherosclerotic vascular disease.

Therapeutic effects of LDL apheresis in the prevention of atherosclerosis

The efficacy and safety of the therapeutic tool which directly removes LDL particles from circulation (LDL apheresis) has already been established for cholesterol-lowering in patients with refractory hypercholesterolemia, such as homozygous familial hypercholesterolemia. Several angiographic studies have demonstrated that regular LDL apheresis therapy had favorable effects on the progression of coronary atherosclerosis. Recently, two clinical reports described excellent long-term follow-up results for patients with coronary artery disease who had been treated with LDL apheresis using dextran sulfate cellulose columns plus adjunctive cholesterol-lowering drug therapy. In addition, there is increasing evidence that LDL apheresis is effective for the prevention of extra-coronary atherosclerotic disease, and it is also reported to have the potential to improve microvascular disorders. Since the mechanisms of clinical improvement caused by LDL apheresis extend beyond simple and drastic reduction of LDL cholesterol, further investigation based on recent vascular biological evidence is needed.