Which urinalysis finding is most characteristic of nephrotic syndrome aside from proteinuria?

Which urinalysis finding is most characteristic of nephrotic syndrome aside from proteinuria?

• A. Red blood cell casts
• B. White blood cell casts
• C. Fatty casts and oval fat bodies
• D. Positive nitrites

Answer: (C)

Nephrotic syndrome causes lipid leakage into the urine, so lipiduria is the hallmark alongside heavy protein loss. The urinalysis finding most characteristic aside from proteinuria is lipid-containing material: fatty casts and oval fat bodies. Fatty casts are casts that trap lipid droplets, and oval fat bodies are tubular cells stuffed with lipids. This lipiduria reflects the combined effects of hypoalbuminemia and liver-driven hyperlipidemia in nephrotic syndrome and helps set it apart from other renal or urinary conditions. In contrast, red blood cell casts point to glomerular inflammation (nephritic processes), white blood cell casts imply inflammatory or infectious processes, and positive nitrites indicate bacterial infection in the urine.

Nephrotic syndrome causes lipid leakage into the urine, so lipiduria is the hallmark alongside heavy protein loss. The urinalysis finding most characteristic aside from proteinuria is lipid-containing material: fatty casts and oval fat bodies. Fatty casts are casts that trap lipid droplets, and oval fat bodies are tubular cells stuffed with lipids. This lipiduria reflects the combined effects of hypoalbuminemia and liver-driven hyperlipidemia in nephrotic syndrome and helps set it apart from other renal or urinary conditions. In contrast, red blood cell casts point to glomerular inflammation (nephritic processes), white blood cell casts imply inflammatory or infectious processes, and positive nitrites indicate bacterial infection in the urine.