Comparison of different Lp (a) elimination techniques: a retrospective evaluation

Lipoprotein (a), abbreviated Lp (a), is accepted as a potential selective or additional risk factor for premature atherosclerosis. Though it may be considered to be closely related to low density lipoprotein, so far attempts to keep it under control with diet or cholesterol lowering medications have failed. Thus, extracorporeal elimination is the only effective treatment approach for patients with premature atherosclerosis. As different techniques for differential elimination such as precipitation, adsorption and filtration exist, it appeared of interest for us to retrospectively evaluate adsorption and filtration procedures in their capacity to lower Lp (a). Four patients with selectively elevated Lp (a) and eight patients with familial hypercholesterolaemia and additional elevated Lp (a) could be evaluated. All patients had Lp (a) values of 80-120 mg/dl without treatment in common. Different plasma or whole blood volumes were processed to obtain 30 mg/dl Lp (a) as post-treatment target values. In patients with a selective elevation Lp (a)-apheresis, as developed from Prokovski, was the most potent elimination procedure, decreasing the Lp (a) by at least 81% of the initial value after processing 6L of plasma followed from LDL-(immune) apheresis with 71%. Plasma differential filtration using the Kuraray LA 4 filter decreased Lp (a) by 70% processing only 3.4 L, however was less selective and limited by the loss of fibrinogen and other high molecular weight proteins. In patients with familial hypercholesterolaemia and Lp (a) elevation in a range of 80-120 mg /dl LDL-(immune) apheresis removed >80% of Lp (a) processing 6L of plasma whereas if 5L were processed a removal of 76% was comparable to liposorption. Neither whole blood perfusion (DALI, Fresenius) nor filtration applying the Kuraray LA 5 filter was able to reach the desired target values.