In systemic amyloidosis due to AL type (primary amyloidosis), the amyloid fibrils are derived from which precursor protein?

• A Immunoglobulin light chains (kappa more often than lambda in AL amyloidosis) ✓
• B Serum amyloid A protein (SAA), an acute-phase reactant
• C Transthyretin (TTR) produced by the liver
• D Beta-2-microglobulin in dialysis-associated amyloidosis

Explanation

AL (amyloid light chain) amyloidosis derives from monoclonal immunoglobulin light chains produced by plasma cell dyscrasias; lambda light chains form amyloid more often than kappa (opposite to the 2:1 kappa:lambda predominance in normal immunoglobulins). AA amyloidosis uses SAA as precursor (chronic inflammation); ATTR uses transthyretin; Aβ2M uses β2-microglobulin.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.