Apolipoprotein a polymorphism predicts lipoprotein a concentration in renal transplant recipients.

Abstract

Increased serum lipoprotein(a) is an independent risk factor for atherosclerosis in renal transplant recipients. Higher levels may be due to genetic factors, for example, apolipoprotein A isoforms and/or environmental states such as drugs and diets. We evaluated 75 renal transplant recipients including 30 men and 45 women of overall mean age of 30 +/- 7 years and transplantation duration of 57 +/- 10 months as well as 30 healthy controls for apolipoprotein A isoforms, lipoprotein(a) concentrations, serum triglycerides, serum cholesterol, serum creatinine, and serum homocysteine concentrations. High- and low-molecular-weight apolipoprotein A isoforms (>35 and <35 kringle 4) were observed in 71% and 29% of renal transplant recipients and 83% and 17% of controls. Average lipoprotein(a) concentration ratios between high- and low-molecular-weight apolipoprotein A isoenzymes were significantly greater in renal transplant recipients than in controls. Lipoprotein A and cholesterol concentrations that did not correlate with each other were not higher among the eight renal transplant recipients with creatinine levels greater than 1.8 mg/dL. Absolute levels in renal transplant recipients with failed grafts also were not different regarding the various apolipoprotein A phenotypes. Homocysteine levels were significantly higher with high-molecular-weight apolipoprotein A isoenzymes. A relationship existed between lipoprotein(a) and triglycerides, but not cholesterol: higher triglyceride levels were associated more with high-molecular-weight isoforms of apolipoprotein A (P = .027). Lipoprotein(a) concentrations are higher in low-molecular-weight isoforms of apolipoprotein but triglyceride levels and homocysteine concentrations are higher among the high-molecular-weight isoforms of apolipoprotein A. This finding could be used as a guideline to select the most appropriate drug for different apolipoprotein A isoforms.