Classification and Etiologies
Nephrotic syndrome can be primary (histopathologic diagnosis) or secondary (presents with the histopathology but with an underlying driving cause).
FSGS
- hyperfiltration syndromes
- obesity
- decreased nephron mass
- congenital renal malformations
- solitary kidney
- HIV associated nephropathy
- APOL1 (2 hit hypothesis)
- Genetic causes --> circulating factors
Membranous Nephropathy (MN)
Can be diagnosed in the right setting with anti-PLA2R (and disease activity can be trended). - Infection (hepatitis/HIV) - Drugs (NSAIDs, gold, penicillamine) - Cancer (solid organ) - Autoimmune (SLE, CTD)
Minimal Change Disease (MCD)
Typically seen most in children (>90% of cases), where it has a good initial treatment response to steroids but trends to be a relapsing disorder. - Lymphoma - NSAIDs