Serum AA amyloidosis complicating chronic inflammatory disease (rheumatoid arthritis, FMF) involves deposition of AA protein derived from which serum precursor, and which organ distribution is most characteristic?
- A Serum amyloid A (SAA) — AA amyloid deposits predominantly in kidney (glomeruli), liver, and spleen ✓
- B Serum amyloid P component (SAP) — deposits as a scaffold in all amyloid types
- C Apolipoprotein A-I — deposits in kidney, heart, and peripheral nerves
- D Beta-2 microglobulin — deposits in carpal tunnel and periarticular tissue of dialysis patients
Explanation
AA amyloidosis (secondary/reactive amyloidosis) results from deposition of AA protein derived from serum amyloid A (SAA), an acute-phase reactant produced by the liver during chronic inflammation. AA amyloid deposits preferentially in the kidney (glomeruli and interstitium causing nephrotic syndrome), spleen (causing 'lardaceous' spleen or 'sago' spleen depending on pattern), and liver (hepatomegaly). Cardiac involvement is less common than in AL amyloidosis. SAP is a universal amyloid component, not a fibril precursor. Beta-2 microglobulin causes dialysis-related amyloid; ApoA-I causes familial amyloidosis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.