Diagnosis
The gold standard in diagnosis of nephrotic syndrome is 24 hour urine protein measurement. Aiding in diagnosis are blood tests and sometimes imaging of the kidneys (for structure and presence of two kidneys), and/or a biopsy of the kidneys.
The following are baseline, essential investigations:
- 24 hour bedside urinary total protein estimation.
Urine sample shows proteinuria (>3.5 g per 1.73 m2 per 24 hours). It is also examined for urinary casts, which are more a feature of active nephritis.
- Comprehensive metabolic panel (CMP) shows hypoalbuminemia: albumin level ≤2.5 g/dL (normal=3.5-5 g/dL).
- Lipid profile.
High levels of cholesterol (hypercholesterolemia), specifically elevated LDL, usually with concomitantly elevated VLDL is typical.
- Electrolytes, urea and creatinine (EUCs): to evaluate renal function.
Further investigations are indicated if the cause is not clear:
- Biopsy of kidney.
- Auto-immune markers (ANA, ASOT, C3, cryoglobulins, serum electrophoresis).
- Ultrasound of the whole abdomen.
Read more about this topic: Nephrotic Syndrome