Effect of HELP-LDL-apheresis on serum concentrations of human lipoprotein(a): kinetic analysis of the post-treatment return to baseline levels.

In addition to LDL, Lp(a) can be quantitatively eliminated from plasma in an extracorporeal LDL-apheresis procedure based on precipitation with heparin at pH 5.12. The rates of return of post-apheresis Lp(a) and LDL-cholesterol concentrations to baseline levels were investigated in six individuals with familial hypercholesterolaemia (one homozygote, five heterozygote) and one normolipaemic individual. The first-order disappearance constants (kappa) were derived for LDL and Lp(a) according to Apstein et al. The kappa values for LDL in the homozygous FH and the normolipaemic individual were 0.082 and 0.43 respectively while the heterozygous FH patients had kappa values intermediate between the two (median 0.231; range 0.116-0.261). The first-order disappearance constants of Lp(a) did not correlate with those of LDL. The homozygous FH and normolipaemic individuals had Lp(a) kappa values of 0.158 and 0.199 respectively; the corresponding values in the heterozygous FH patients were: median 0.142; range 0.045-0.179.