Rapidly progressive glomerulonephritis complicating primary AL amyloidosis and multiple myeloma.

Crescentic glomerulonephritis is a rare complication of AA amyloidosis. There are no clinical case reports of this complicating AL amyloidosis. A 67-year-old man developed rapidly progressive glomerulonephritis (RPGN) on a background of primary AL amyloidosis and IgGkappa multiple myeloma. Investigations for causes of glomerulonephritis were negative, and a renal biopsy confirmed crescentic glomerulonephritis and amyloid deposition. He progressed to end stage kidney disease (ESKD) requiring dialysis after 2 months and died 7 months after diagnosis after further treatment of multiple myeloma failed to arrest progression. We believe this to be the first clinical case report of RPGN complicating primary (AL) renal amyloidosis and multiple myeloma.