The effect of renal failure and haemodialysis on the concentration of free apolipoprotein A-1 in serum and the implications for the catabolism of high-density lipoproteins.

Free apolipoprotein A-1 (free A-1) was measured by quantitative crossed immunoelectrophoresis in 43 patients with severe chronic renal failure. The free A-1 concentrations in these patients were higher than in 28 healthy subjects irrespective of whether they where receiving haemodialysis or conservative treatment. A close correlation was found between serum concentration of free A-1 and creatinine in patients with varying degrees of chronic renal failure (r = 0.717, p less than 0.001). In three patients who received renal transplants serial measurements of free A-1 showed a decrease to normal levels within two days post-operatively. These findings suggest a relationship between the serum concentration of free A-1 and glomerular filtration. In conjunction with the report implicating the kidney as the major site of catabolism of Apo A-1 in the rat, these results suggest a similar role for the kidney in man. No evidence has been found linking free A-1 with hypertriglyceridaemia in patients with renal failure as has been suggested previously.