Which serum protein is used as a biochemical marker of amyloid deposition activity in AA amyloidosis, as it reflects the acute phase reactant that serves as the precursor protein?

• A C-reactive protein (CRP)
• B Ferritin
• C Serum amyloid A (SAA) ✓
• D Fibrinogen

Explanation

Serum amyloid A (SAA) is an HDL-associated acute phase reactant synthesized by the liver in response to IL-1, IL-6, and TNF. In AA amyloidosis, SAA is the direct precursor protein that is incompletely degraded and polymerizes into amyloid A fibrils. Monitoring serum SAA levels helps assess disease activity and inflammation control in patients at risk for AA amyloidosis (e.g., rheumatoid arthritis, chronic osteomyelitis). CRP is another acute phase reactant but is not the direct amyloid precursor.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.