Changes in phenotypes of apolipoprotein E and apolipoprotein(a) in liver transplant recipients

The aim of this study has been to confirm that liver is the main site of apolipoprotein (apo) E and apo(a) synthesis, based in the changes of their phenotypes after transplantation. Apo E phenotypes were studied in 34 patients and apo(a) phenotypes in 27 of them before and after liver transplant. Thirteen patients changed the apo E phenotype after transplantation. Eight patients with E3/3 phenotype changed to the others with 2 or 4 alleles. Three patients with E4/3 phenotype changed to E3/3, one changed from E3/2 to E3/3 and another one changed from E4/2 to E3/2 phenotype after transplantation, Twenty one of the 27 patients changed the apo(a) phenotype. Thirteen of them also changed lipoprotein (Lp)(a) serum concentration at least twofold, showing in 11 an increase and in 2 a decrease, in relation with the change to phenotype associated with high and low Lp(a) concentration, respectively. Changes in apo E and apo(a) phenotypes in liver transplant recipients studied show that most of these apolipoproteins are synthesized by the liver.