A case of nephrotic syndrome with glomerular lipoprotein deposition with capillary ballooning and mesangiolysis

A 33-year-old man with nephrotic syndrome and rapid deterioration of renal function showed curious glomerular morphological abnormalities. Ballooning of the glomerular capillaries due to a substance accumulated in the capillary lumina and mesangiolysis were prominent histological features. The deposits in the capillary lumen were positive for Sudan III staining, and also for beta-lipoprotein, apoprotein B and apoprotein E by immunofluorescent technique. The staining of beta-lipoprotein in a flower leaf pattern was a striking characteristic, while such staining was negative when studied in 20 patients with nephrotic syndrome who were used as controls. Based on these findings, the morphological abnormalities in this case were considered to be related to lipoprotein deposition in the glomeruli. This case is thought to be the first reported in a complete form in the literature which could be classified as a new kind of disease related to lipoprotein metabolism abnormalities.