## Organ Tropism in Systemic Amyloidosis **Key Point:** The kidney (specifically the glomeruli) is the most frequently affected organ in systemic amyloidosis, occurring in approximately 70% of patients with systemic disease. ### Renal Amyloidosis #### Pathology - Amyloid deposits in the **glomerular basement membrane** and **mesangium** - Causes progressive glomerulonephritis leading to nephrotic syndrome - Results in chronic kidney disease and eventual renal failure if untreated #### Clinical Presentation 1. Nephrotic-range proteinuria (>3.5 g/day) 2. Hypoalbuminemia and edema 3. Hyperlipidemia 4. Progressive decline in GFR ### Organ Involvement Frequency in Systemic Amyloidosis | Organ | Frequency (%) | Clinical Manifestation | |---|---|---| | **Kidney** | **70** | Nephrotic syndrome, CKD | | Heart | 25 | Restrictive cardiomyopathy, arrhythmias | | Liver | 20 | Hepatomegaly, rarely liver failure | | Nervous system | 15 | Peripheral neuropathy, autonomic dysfunction | | GI tract | 10 | Malabsorption, bleeding | **High-Yield:** Renal involvement is the **most common** cause of morbidity and mortality in systemic amyloidosis. Cardiac involvement, though less frequent, is the most serious prognostically. **Clinical Pearl:** Renal amyloidosis should be suspected in any patient with nephrotic syndrome + systemic features (hepatomegaly, cardiomegaly, neuropathy) or a history of chronic inflammation. **Warning:** Do not confuse frequency of involvement with severity. Cardiac amyloidosis, though less common, carries the worst prognosis (median survival 6 months if untreated).
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.