Amyloidosis and the Kidney

Abstract

Amyloidosis results from deposition of fibrillar proteinaceous material in the extracellular space in organs and tissues. Diagnosis is made microscopically on biopsy by visualizing apple-green birefringence in Congo red-stained sections under polarized light. Renal amyloidosis most often leads to glomerular deposits, resulting in proteinuria. If untreated, progressive decline in renal function can culminate in end stage renal disease. The type of protein that forms the fibrils can vary, but the result is disruption of structure and function. Renal impairment is seen most often in reactive secondary amyloidosis from serum amyloid A, monoclonal immunoglobulin light chain amyloidosis and amyloidogenic leukocyte chemotactic factor 2 (ALECT2) amyloidosis a recently described amyloid-forming protein. When possible, decreasing production of the amyloidogenic precursor or removing the amyloid protein may regress amyloid deposits and stabilize or improve renal function. Kidney transplantation may be indicated for carefully selected patients with amyloid-induced end stage renal disease.