From the Guidelines
Nephrotic syndrome is primarily caused by damage to the glomeruli, with the most common causes including minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and diabetic nephropathy, as outlined in the 2021 KDIGO clinical practice guideline for the management of glomerular diseases 1.
Causes of Nephrotic Syndrome
The causes of nephrotic syndrome can be categorized into primary and secondary glomerular diseases. Primary glomerular diseases include:
- Minimal change disease, which is the most common cause in children
- Focal segmental glomerulosclerosis (FSGS)
- Membranous nephropathy Secondary glomerular diseases include:
- Diabetic nephropathy, which is a common cause in adults
- Systemic diseases such as lupus nephritis, amyloidosis, and HIV-associated nephropathy
- Certain medications like NSAIDs, gold, penicillamine, and some chemotherapy drugs
- Infections including hepatitis B, hepatitis C, and malaria
- Genetic mutations affecting podocyte proteins, which can cause congenital forms of nephrotic syndrome
Pathophysiology
The fundamental pathophysiology of nephrotic syndrome involves damage to the glomerular filtration barrier, particularly the podocytes and their slit diaphragms, which normally prevent protein leakage 1. This damage allows proteins, especially albumin, to escape into the urine, resulting in the classic symptoms of proteinuria, hypoalbuminemia, edema, and hyperlipidemia that characterize nephrotic syndrome.
Management
The management of nephrotic syndrome depends on the underlying cause and may involve immunosuppressive therapy, supportive care, and treatment of any underlying systemic disease, as discussed in the KDIGO guideline 1. It is essential to accurately diagnose the cause of nephrotic syndrome to provide appropriate treatment and improve patient outcomes.
From the Research
Causes of Nephrotic Syndrome
The causes of nephrotic syndrome can be primary or secondary. Primary causes include:
- Idiopathic minimal change disease, which is the most common cause in children 2, 3
- Focal segmental glomerulosclerosis (FSGS), which is a common cause in both children and adults 2, 4, 3
- Membranous nephropathy (MN), which is a common cause in adults 2, 5, 6
Secondary Causes
Secondary causes of nephrotic syndrome include:
- Diabetes mellitus 2, 5, 6
- Systemic lupus erythematosus 2, 5, 3
- Amyloidosis 2
- Hematologic malignancies 2
- Infections 2
- Gene mutations 3
Diagnosis and Evaluation
Diagnosis and evaluation of nephrotic syndrome involve: