Warning
Effacement of foot processes of the podocytes cannot be seen on LM, but only on EM!
- Epidemiology
- Most common cause of Nephrotic Syndrome in children (peak age 2–6 years).
- Can occur in adults (less common).
- Etiology & Pathophysiology
- Primary: Idiopathic (most common).
- Secondary associations:
- Hodgkin lymphoma (classic association due to cytokine release).
- NSAID use.
- Immunizations or recent viral infections.
- Mechanism:
- Systemic T-cell dysfunction leads to production of glomerular permeability factor (likely cytokines like IL-13).
- Cytokines cause damage to podocytes and loss of negative charge (heparan sulfate) on the Glomerular Basement Membrane (GBM).
- Result: Selective Proteinuria (primary loss of albumin, sparing larger proteins like immunoglobulins).