Prospective cross‐over comparisons of three low‐density lipoprotein (LDL)‐apheresis methods in patients with familial hypercholesterolaemia

We prospectively compared effectiveness, selectivity and biocompatibility of three LDL-apheresis methods, immunoadsorption (IMAL), dextran sulphate adsorption (DSAL) and heparin-induced extracorporeal LDL precipitation (HELP). Seven patients with familial hypercholesterolaemia were treated twice with each method in random sequence. Reduction in atherogenic lipoproteins was without significant difference: LDL -60% to -75%, VLDL -20% to -30%, triglycerides -20% to -42%. High-density lipoprotein (HDL)-cholesterol was reduced by IMAL only (-27%, P < 0.05); DSAL and HELP did not decrease HDL. Total plasma protein reduction was 13-15% with each method, indicating unselectivity. Albumin was significantly decreased by IMAL (-15%, P < 0.05) but not by the other methods. DSAL and HELP reduced fibrinogen (-40%, -58%, P < 0.0001) and other clotting factors. IMAL had almost no effect on coagulation. The white blood cell count did not change. C3 and C4 complement were decreased (-20% to -46%) by all methods. C5a complement did not increase in systemic blood, but was increased in the extracorporeal circulation of IMAL (+200%) and HELP (+150%). Plasma PMN elastase rose in all methods (+200%) indicating neutrophile degranulation. In conclusion, in this short-term study of a small patient population, effectiveness of the three LDL-apheresis methods was similar, but selectivity and biocompatibility were different. The therapeutic relevance of these differences for long-term treatment remains to be elucidated.