Effect of renal transplantation on lecithin cholesterol acetyltransferase (LCAT) activity and plasma lipids.

The rate of free cholesterol esterification, assessed as lecithin cholesterol acyltransferase (LCAT E.C. 2.3.1.43) activity, and cholesterol as well as triglycerides plasma levels, were determined in 45 patients who had been operated for kidney transplantation. An increased concentration of cholesterol and triglycerides was found in 25% and 31% of tests, respectively, whereas subnormal molar esterification rate (MER) could be detected in 74%, and a reduced cholesterol turnover in the endogenous pool (fractional esterification rate - FER) in as many as 95% of cases. Examination of different time intervals after transplantation surgery revealed that the lowest rate of esterification, as well as the lowest concentration of cholesterol was consistently found early after transplantation (within 10--15 days). The values subsequently rose but even 6--24 months after a successful kidney transplantation the molar and fractional esterification rates of cholesterol in most of the patients did not attain the levels of the healthy control subjects. If the function of the grafted kidney failed and the patient had to be returned to the haemodialysis treatment programme, all examined parameters remained permanently low. These results suggest that a disturbance in cholesterol metabolism accompanies an apparently satisfactory functioning of the transplanted kidney, even though it need not necessarily be reflected in increased plasma cholesterol concentrations.