ELEVATED LIPOPROTEIN-(A) LEVELS IN PRIMARY NEPHROTIC SYNDROME

Elevated plasma levels of total cholesterol and increase in the hepatic synthesis of some apo B-containing lipoproteins have been noted in the nephrotic syndrome. Apoprotein (a), the apolipoprotein distinguishing lipoprotein (a) [Lp(a)) from low-density lipoprotein, is equally of hepatic origin, and Lp(a) recently has been shown to possess both atherogenic and thrombogenic activities. However, little is known of Lp(a) levels in nephrotic patients. We measured plasma Lp(a) concentrations in 11 patients with primary nephrotic syndrome in the absence of hematuria, hypertension, and renal insufficiency. Histologic lesions were minimal-change disease in five cases, membranous glomerulopathy in four cases, and focal and segmental glomerulosclerosis in two cases. Mean levels of Lp(a) (98 ± 92 mg/dL [mean ± SO)) were markedly elevated in the nephrotic patients as compared with the controls (14 ± 13 mg/dL). No correlation was noted between plasma Lp(a) and proteinuria, albuminemia, total cholesterolemia, low-density lipoprotein cholesterol, apoprotein B100, or plasminogen. Furthermore, there was no correlation between Lp(a) levels and apoprotein (a) isoform size. In four patients, the level of Lp(a) decreased approximately fourfold after remission of the nephrotic syndrome under corticosteroid treatment. Our observation that Lp(a) levels are elevated in the nephrotic syndrome is consistent with the hypothesis that these patients may be at an increased risk of cardiovascular and thrombotic complications. © 1993, National Kidney Foundation. All rights reserved. All rights reserved.