Effect of immune complexes on plasma HDL-cholesterol in rabbits

The effect of immune complexes on plasma lipids, especially on high density lipoprotein (HDL) cholesterol, was studied in rabbits. In rabbits immunized twice with bovine serum albumin (BSA) with an interval of about 6 weeks, a significant decrease in plasma HDL-cholesterol (P less than 0.01) and in the HDL/total cholesterol ratio (P less than 0.02) was found 6 days after the second BSA injection. As a result of repeated bleedings commenced 6 days after the second BSA injection, the changes in plasma triglycerides (TG) and total cholesterol (TC) were similar to those found previously in non-immunized rabbits. In contrast to the findings in non-immunized rabbits, no significant decrease in HDL-cholesterol was found as a consequence of the bleedings, but a negative correlation (P less than 0.05) between plasma TG and HDL-cholesterol appeared. It is concluded that immune complexes may affect plasma HDL-cholesterol concentrations and thereby possibly also the development of atherosclerosis.