LABORATORY DATA & MICROSCOPIC DESCRIPTIONS:
At the time of renal biopsy, proteinuria measured 1.4 grams/day, serum creatinine 1.2 mg%, and blood urea nitrogen (BUN) 13 mg%.
The biopsy was entirely of cortex and showed a total of 11 glomeruli, one of which was totally sclerotic. The podocytes appeared diffusely distended by numerous intracytoplasmic vacuoles. Segmental sclerosis was seen in one glomeruli, but otherwise the glomerulus were normocellular with no other specific abnormalities. The interstitium showed a mild increase in collagen deposition and scattered foam cells.
Immunofluorescence microscopy showed granular mesangial staining for IgM (1+) and C3 (1+). There was also focal peripheral glomerular basement membrane staining for C3 (2+). IgG, IgA, C4, and properdin stains were negative.
Ultrastructural studies showed numerous lamellated whirls of myelin-like bodies within podocytes. Similar material was also present within the tubular epithelial cells and interstitial foam cells.