Distinct effects of LDL apheresis by hemoperfusion (DALI) and heparin-induced extracorporeal precipitation (HELP) on leukocyte respiratory burst activity of patients with familial hypercholesterolemia

Hypercholesterolemia and oxidative stress are major risk factors in atherogenesis. In the last years, lipid apheresis has been established as an effective clinical therapy by lowering not only elevated plasma low-density lipoprotein (LDL) levels but also by reducing the incidence of cardiovascular events. The aim of the present study was to investigate peripheral leukocyte oxidant generation in patients with familial hypercholesterolemia (FH) undergoing regular LDL apheresis. The activity state of leukocytes was estimated prior to, immediately after, and 2 days after LDL apheresis carried out by two distinct techniques: hemoperfusion with the DALI system and heparin-induced extracorporeal LDL precipitation (HELP). Oxidant generating activity was measured by chemiluminescence (CL) in whole blood and isolated polymorphonuclear leukocytes (PMNL). The results of our study show increased baseline respiratory burst activities in FH patients as compared to healthy controls. Apheresis with the HELP system was followed by increases in leukocyte count, zymosan-induced whole blood CL, and plasma PMNL elastase levels. The DALI technique caused no changes in leukocyte count and elastase levels and decreased whole blood CL activity. Two days after lipid removal the observed changes returned to pre-apheresis levels. Leukocyte activity parameters before and after apheresis did not correlate with the corresponding plasma levels of triglycerides, total cholesterol, and LDL cholesterol, suggesting that different handling in the framework of both apheresis techniques rather than lipid profile changes during therapy accounted for leukocyte activity modulation.