Abnormalities in cholesteryl ester transfers may play a role in the development of atherosclerosis observed in patients with end-stage renal failure treated by chronic hemodialysis. Net neutral-lipid transfers and cholesteryl ester transfer protein activity and mass were investigated in 20 hemodialyzed patients, arbitrarily divided into two groups based on fasting triglyceride levels, and compared to triglyceride-matched control groups. In the hypertriglyceridemic subjects (plasma triglyceride values > 150 mg/dl), high-density lipoprotein cholesterol was decreased, and the net cholesteryl ester transfer rates were significantly higher than the rates in normolipidemic subjects. The comparison of subjects matched for plasma triglyceride and cholesterol levels showed no significant difference in cholesteryl ester or triglyceride transfer rates between patients and controls. Our results suggest that normal or elevated net neutral-lipid transfers are not related to the renal status of the subjects, but rather to their plasma triglyceride levels.

Serum and isolated low-density lipoprotein (LDL) composition abnormalities were investigated in 20 hemodialyzed patients with chronic renal failure and 15 healthy normolipidemic subjects for comparison. LDL apolipoprotein B (apo B) epitope accessibility was determined by the use of seven monoclonal antibodies (Mabs). These Mabs recognize fragments on the N-terminal part of apo B (Mabs B1, B4), on the middle part (Mab BL7), on the C-terminal (Mabs BA11, BL3), and the two remaining Mabs recognize conformational epitopes of apo B (BL5, DA7). Mab BA11 recognizes a fragment of apo B which interacts with the B/E receptor. In hemodialyzed patients, LDL content of triglycerides (P < 0.001) and apo CIII (P < 0.005) was increased, while cholesteryl esters (P < 0.005) were decreased. The accessibility of BL5 epitopes of LDL apo B was enhanced (P < 0.05), while BA11 epitope expression was decreased (P < 0.01). The conformation of patients' LDL (CRF-LDL) was probably abnormal and seemed to be related to some modification of the lipidic environment. It is important to consider a structural modification as it alters the B/E receptor recognition domain of apo B. These results confirm LDL abnormalities in hemodialyzed patients and suggest a possible modification of the recognition of the LDL by cells.

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