Lecithin: cholesterol acyltransferase activity in dialyzed and undialyzed chronic uremic patients.

Lecithin cholesterol acyltransferase (LCAT) and lysolecithin acyltransferase (LAT) activities in plasma were significantly lower in undialyzed than in dialyzed uremic patients and controls. Both LCAT and LAT activities were normal in the maintenance dialysis group. The free/total cholesterol ratio was significantly increased in the undialyzed patients only. This ratio and LCAT were inversely related in the dialyzed group, unrelated in the undialyzed patients, and positively correlated in controls. Unlike non-uremic populations with hypertriglyceridemia in which LCAT is increased, no correlation was found between plasma triglyceride and LCAT in the uremic population studied. Our results show that both LCAT and LAT activities are reduced in undialyzed chronic uremic patients but are not significantly different from control levels in patients treated with chronic hemodialysis. These results indicate that the changes in LCAT activity contrast with those described in lipoprotein composition and metabolism which do not appear to be affected by chronic dialysis therapy.