The rebound of lipoproteins after LDL-apheresis. Effects on chemical composition and LDL-oxidizability

Lipoprotein apheresis - Shortening of treatment intervals reduces cardiovascular events: Case reports

BACKGROUND

Lipoprotein (Lp-) apheresis is a life-long therapy, usually performed in weekly intervals. In some cases, however, atherosclerotic disease progresses despite adequate therapy with weekly Lp-apheresis and maximal lipid lowering medication. In an attempt to improve the effectiveness of therapy, we temporarily shortened treatment intervals of Lp-apheresis in patients with elevated lipoprotein(a) (Lp(a)) and further progression of coronary atherosclerosis despite weekly Lp-apheresis and maximal lipid lowering medication.

METHODS

We illustrate three case reports of patients with elevated Lp(a), who underwent regular weekly Lp-apheresis treatment for secondary prevention. The intensified treatment protocol contained three therapies in two weeks (alternating 2 per week and 1 per week).

RESULTS

The shortening of treatment intervals achieved a stabilization of atherosclerotic disease in case 1. After a total of 68 therapies in 52 weeks (1.31 sessions/week) the elective coronary angiography revealed excellent long-term results. In case 2, the intensified treatment protocol is still ongoing. The patient reported a decrease in angina pectoris and an increase in exercise capacity since the beginning of more frequent therapy sessions. In some cases, as it is shown in case 3, a fast decision for shortening the treatment intervals is necessary.

CONCLUSIONS

The intensified treatment regimen resulted in an improvement in clinical symptoms and no further progression of atherosclerosis. In conclusion, shorter therapeutic Lp-apheresis intervals, at least temporarily, should be considered in patients who suffer from clinical and/or angiographic progression of atherosclerosis, despite maximal lipid lowering medication and weekly Lp-apheresis.

Antioxidant defense system in familial hypercholesterolemia and the effects of lipoprotein apheresis

Oxidative stress is thought to play an important role in the pathogenesis of disorders associated with atherosclerosis. Alpha-tocopherol is considered to be an effective lipophilic antioxidant, which protects lipid membranes against peroxidation and thus prevents cell damage by reaction with free radicals. However, measurement of alpha-tocopherol concentration in serum does not reflect the content of α-tocopherol in membranes whereas erythrocyte alpha-tocopherol may be good indicator of antioxidative status. Therefore a simple isocratic reversed phase HPLC method has been developed and validated for the determination of alpha-tocopherol in human erythrocytes in a clinical setting. The content of alpha-tocopherol in human erythrocyte membrane and lipoperoxidation were studied in patients with severe hypercholesterolemia treated by lipoprotein apheresis. The group of hypercholesterolemic patients (n = 14) treated by lipoprotein apheresis was compared to healthy adult normolipidemic controls. After lipoprotein apheresis, the content of in membrane alpha-tocopherol did not change significantly despite decreased tocopherol in serum and lipoprotein fractions. We observed significantly decreased lipoperoxidation as revealed by serum TBARS, representing end products of lipid peroxidation, which increased from third day afterwards and remained significantly higher in comparison to controls until the next LDL-apheresis. We conclude that aggressive lipid lowering procedure with lipoprotein apheresis was associated with favorable transient decrease of lipoperoxidation. Simultaneously the cell membrane bound antioxidative defense mechanisms as reflected by the content of alpha-tocopherol in human erythrocyte membrane where not depressed in spite of its decreased plasma lipid carrier. Another variables involved remain to be investigated.

Low-density lipoprotein apheresis in the treatment of peripheral arterial disease

Low-density lipoprotein (LDL) apheresis is performed in patients with homozygous familial hyper-cholesterolemia who lack LDL receptors and with heterozygous familial hypercholesterolemia who are LDL receptor deficient with documented, symptomatic coronary artery disease who are resistant to diet changes and maximum drug therapy. LDL apheresis can reduce or abolish anginal symptoms and improve coronary lesions. Several reports reveal the improvement of insufficient peripheral blood flow. By extensively removing blood LDL and changing coagulation factors and various vasoactive substances, LDL apheresis improves blood rheology and thereby peripheral circulation. It seems worth trying on all patients with arteriosclerotic lesions, even if they are normocholesterolemic.