Apolipoprotein a polymorphism predicts lipoprotein a concentration in renal transplant recipients

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.