Three-year treatment of familial heterozygous hypercholesterolemia by extracorporeal low-density lipoprotein immunoadsorption with polyclonal apolipoprotein B antibodies

Abstract

Familial hypercholesterolemia is a disorder of lipid metabolism associated with a highly increased risk for cardiovascular disease. Since in such patients even combined drug therapy often fails to decrease low-density lipoprotein (LDL) cholesterol levels sufficiently, extracorporeal LDL elimination has been developed. We treated eight adult patients with LDL immunoadsorption using antibodies against apolipoprotein B without additional lipid-lowering drug therapy for 3 years; this procedure was performed at weekly intervals. By one treatment session, LDL cholesterol and lipoprotein(a) levels were decreased by 55%. Under regular treatment, mean LDL cholesterol levels of 165 mg/dL between two consecutive treatment sessions could be reached, compared with 522 ± 24 mg/dL before any treatment. As high-density lipoprotein (HDL) cholesterol levels increased under regular treatment, the LDL HDL cholesterol ratio decreased from 13.4 to 3.4. Positive influences on plasma and whole-blood viscosity as well as on erythrocyte aggregation also seem to be beneficial with regard to retarding atherosclerosis. Very-low-density lipoprotein (VLDL) levels were reduced by approximately 50% after treatment, accompanied by a marked increase of lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) activity. The effects of LDL apheresis on hemostasis, complement activation transport proteins, and hematological parameters were found to be small. In addition, no side effects amounting to any major clinical relevance occurred in any of the patients. After 3 years of LDL apheresis, a decrease in the frequency of anginal chest pain and ST segment depression on exercise testing and a marked reduction of tendon xanthoma size were observed.