Extracorporeal elimination of
LDL-cholesterol is at present an important part of comprehensive treatment of patients with very
high cholesterol levels. An absolute indication for their use are patients with the homozygous form of familial hypercholesterolaemia. Treatment is, after individual consideration, indicated also patient with severe heterozygous familial hypercholesterolaemia, with a positive family history of IHD, if it is not possible to reduce
LDL-cholesterol by diet and hypolipidaemic agents below 5.2 mmol/l; also patients with severe IHD and severe hypercholesterolaemia, included in
secondary prevention where it is not possible to reduce
LDL-cholesterol by diet and
pharmacotherapy below 3,4 mmol/l. Another indication for treatment by
LDL apheresis are patients where cardiosurgery cannot be performed because of angiosclerosis. These are patients with severe hypercholesterolaemia which does not respond to drugs and with diffuse changes of the coronary circulation in young age, which cannot be treated by angioplasty or coronary bypass, and also patients after a coronary bypass with a refractory disorder of the lipid metabolism.
LDL apheresis is furthermore indicated in patients with severe hyperlipidaemic crises which eventually develop into
necrosis of the pancreas. Long-term
LDL-
apheresis leads to regression of manifestations of
xanthomatosis of the skin and tendons, it prevents progression and starts regression of
atherosclerosis in patients with severe hypercholesterolaemia. In homozygotes with familial hypercholesterolaemia treatment by
LDL-
apheresis leads to
prolongation of life and improves the quality of life. In heterozygotes neither prolongation of the life span nor a lower incidence of IHD is observed, while the quality of life improves and regression of
atherosclerosis occurs. A combination of
LDL-
apheresis, dietary provisions and hypolipidaemic treatment in heterozygotes is the most effective method to reduce the
LDL-cholesterol level. Extracorporeal elimination of
LDL-cholesterol can be done by non-selective centrifuging or membrane
plasmapheresis. More recent methods of
LDL-
apheresis are more selective and effective. They use active columns or capsules to remove atherogenic particles from plasma. These methods include cascade filtration, immunoadsorption
heparin-induced
LDL precipitation, thermofiltration and
dextran-induced
LDL precipitation.