Low-density lipoprotein oxidation is increased in kidney transplant recipients

Oxidative modification of low-density lipoproteins (LDL) plays an important role in the pathogenesis of atherosclerosis. In addition, there is evidence that chronic vascular allograft rejection may be mediated by oxidised LDL. Plasma lipoprotein concentrations and parameters of LDL oxidation were determined in 19 kidney transplant recipients and 19 healthy controls. Plasma triglycerides and total cholesterol was significantly higher in patients than in the controls. The mean LDL diameter was smaller in patients than in the controls (23.6 +/- 0.71 nm vs 27.78 +/- 1.16 nm, P < 0.002). Furthermore, the lag time of copper-induced in vitro LDL oxidation was shorter in patients than in the controls (101 +/- 23 min vs 148 +/- 81 min, P = 0.02). The titre and concentration of both IgG and IgM autoantibodies against malondialdehyde-modified LDL (MDA-LDL) were higher in the patients. We conclude that there is in vitro and in vivo evidence of increased LDL oxidation in renal transplant recipients. This might facilitate the progression of atherosclerosis and enhance the process of chronic vascular rejection.