In patients with plasma cell disorders, nephrotic syndrome can result from which process?

• A. Hypercoagulability
• B. Amyloidosis
• C. Hyperkalemia
• D. Hypercalcemia

Answer: (B)

Nephrotic syndrome in plasma cell disorders is most often due to AL amyloidosis. In these conditions, abnormal plasma cells produce light chains that misfold and deposit in the kidneys as amyloid within the glomeruli. This disrupts the glomerular filtration barrier, leading to heavy protein loss in the urine and resulting hypoalbuminemia, edema, and the lipid abnormalities seen in nephrotic syndrome. While hypercalcemia and hyperkalemia can accompany plasma cell diseases and renal dysfunction in other ways, they do not by themselves cause nephrotic-range proteinuria via glomerular amyloid deposition. Hypercoagulability can occur as a consequence of nephrotic syndrome overall, but the initiating process in this context is amyloid deposition.