Which combination of imaging and proteinuria features helps differentiate nephrotic syndrome from nephritic syndrome?

• A. Nephrotic: heavy proteinuria with hypoalbuminemia and lipiduria; Nephritic: RBC casts and modest proteinuria
• B. Nephrotic: lipiduria; Nephritic: RBC casts and edema
• C. Nephrotic: hematuria; Nephritic: proteinuria
• D. Nephrotic: low cholesterol; Nephritic: high triglycerides

Answer: (A)

The key idea is distinguishing nephrotic from nephritic syndrome by how much protein is lost in the urine and what the urine sediment shows. In nephrotic syndrome the glomerular barrier is so permeable that large amounts of protein spill into the urine; this causes heavy proteinuria, low blood albumin (hypoalbuminemia), and lipiduria due to increased hepatic lipoprotein production. This combination—heavy proteinuria with hypoalbuminemia and lipiduria—is the hallmark of nephrotic syndrome.

In contrast, nephritic syndrome arises from glomerular inflammation that bleeds into the urine. The urine sediment characteristically contains red blood cell casts from bleeding within the nephron, and while proteinuria is present, it is typically modest rather than massive. Edema and hypertension can occur but massive protein loss and lipiduria are not expected.

So the best match is heavy proteinuria with hypoalbuminemia and lipiduria for nephrotic syndrome, paired with red blood cell casts and modest proteinuria for nephritic syndrome. This contrast in proteic loss scale and sediment findings is what most clearly differentiates the two.