The Answer is D) Glomerular hematuria
Glomerular hematuria is NOT a main feature of nephrotic syndrome. While it may occasionally be present in some glomerular diseases that cause nephrotic syndrome, it is not a defining characteristic and is more typical of nephritic syndrome 1, 2.
The Classic Tetrad of Nephrotic Syndrome
Nephrotic syndrome is definitively characterized by four main features 1, 3, 4:
- Proteinuria >3.5 g/24 hours (or >3 g/24 hours in some definitions) - This is the hallmark feature
- Hypoalbuminemia (<3.0 g/dL or <30 g/L) - Results from urinary protein loss
- Peripheral edema - Consequence of hypoalbuminemia and altered oncotic pressure
- Hyperlipidemia - Compensatory hepatic protein synthesis leads to increased lipid production
Why Hematuria Doesn't Fit
Hematuria, particularly glomerular hematuria with red cell casts, is a cardinal feature of nephritic syndrome, not nephrotic syndrome 2. The nephritic syndrome is characterized by:
- Hematuria (often with red cell casts and dysmorphic RBCs)
- Proteinuria (typically <3.5 g/24 hours)
- Hypertension
- Acute kidney injury
- Oliguria
Important Clinical Distinction
While the KDIGO 2021 guidelines 5 recommend routine evaluation of urine sediment for erythrocyte morphology in all forms of glomerular disease, and some patients with nephrotic syndrome may have microscopic hematuria, this is not a defining feature of the syndrome itself. When significant hematuria is present alongside nephrotic-range proteinuria, it suggests a mixed nephrotic-nephritic picture or specific diagnoses like membranoproliferative glomerulonephritis or lupus nephritis 6.
The presence of significant glomerular hematuria in a patient with heavy proteinuria should prompt consideration of diagnoses beyond typical nephrotic syndrome and may indicate a more aggressive glomerular disease requiring different management approaches.