Acute effects of lipid apheresis on human serum lipidome

Lipid apheresis is an efficient method for reducing cholesterol and triglyceride serum levels, but its effect on other lipid species has not been investigated. This study explored the effect of LDL apheresis on the serum lipidome in hyperlipidemic patients with cardiovascular complications. Lipid analysis was performed before and immediately after a single apheresis procedure in serum samples of six patients treated with different apheresis methods. Conventional lipid parameters (TC, LDL-C, HDL-C, TG) were determined by standard enzymatic methods. Phosphatidylcholines (PC), sphingomyelins (SM), phosphatidylethanolamines (PE), PE-based plasmalogens (PE_pl), lysophosphatidylcholines (LPC), ceramides (Cer), free cholesterol (FC) and cholesterol ester (CE) were detected with electrospray ionization tandem mass spectrometry. LDL apheresis induced a mean reduction of LDL-C by 68% and of HDL-C by 14%, respectively. CE, FC, SM, and Cer revealed an apheresis-induced decrease of about 47%, which was not statistically different from LDL-C reduction. In contrast, the decline of PC (31%), LPC (26%), PE (2%), and PE_pl (37%) after apheresis was significantly lower in comparison to LDL-C reduction, but not statistically different from HDL-C decrease. While the group of PC-species declined uniformly during apheresis, changes in particular LPC-, Cer-, and SM-species revealed significant differences, reflecting their differential distribution in lipoprotein particles and blood cells. We conclude that the acute effect of lipid apheresis on serum lipidome could be predominantly attributed to lipoprotein changes, while blood cell damages during this procedure caused additional, less pronounced changes. The importance of specific changes in particular lipid species remains to be established.