Systemic (AL) amyloidosis most commonly results from which precursor protein, and what is the underlying plasma cell disorder?

• A Serum amyloid A protein; chronic inflammation
• B Transthyretin (TTR); hereditary or senile cardiac amyloidosis
• C Beta-2 microglobulin; long-term hemodialysis
• D Immunoglobulin light chains (kappa or lambda); plasma cell dyscrasia/myeloma ✓

Explanation

Primary (AL) amyloidosis is caused by clonal plasma cells secreting immunoglobulin light chains (most often lambda > kappa) that misfold and aggregate as amyloid fibrils. It is the most common form of systemic amyloidosis in Western countries and is associated with multiple myeloma, MGUS, or Waldenström macroglobulinemia. AA amyloidosis uses serum amyloid A as precursor (reactive/secondary form). ATTR uses transthyretin. Beta-2 microglobulin causes dialysis-related 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.