Epidemiology
Most common cause of nephrotic syndrome in adults of European, Middle Eastern, or North African descent
Etiology
- Most common cause of primary nephrotic syndrome (NS) in Caucasian adults.
- Primary (idiopathic) (~70-80%): Autoantibodies against PLA2R (phospholipase A2 receptor) on podocytes.
- Secondary causes (~20-30%):
- Malignancy: Solid tumors (lung, colon, breast, prostate) — critical to screen elderly pts.
- Infections: HBV, HCV, Syphilis, Malaria.
- Autoimmune: SLE (Class V lupus nephritis), Rheumatoid Arthritis, Thyroiditis.
- SLE can lead to membranous nephropathy or diffuse proliferative glomerulonephritis
- Drugs: NSAIDs, Penicillamine, Gold, Captopril.
Pathophysiology
Anti-phospholipase A2 receptor antibodies (anti-PLA2R antibodies) bind to PLA2R (an autoantigen in glomerular podocytes) and thereby form immune complexes that activate the complement system, leading to podocyte injury.
Clinical features
Diagnostics
There is diffuse thickening of the glomerular basement membrane and capillaries.
