Amyloid light-chain amyloidosis presented as focal segmental glomerulosclerosis in a kidney transplant recipient

Amyloid light-chain (AL) amyloidosis after kidney transplantation is a rare disease in the world, and only one case of systemic AL amyloidosis after kidney transplantation is reported in Korea. We here report a 46-year-old woman with AL amyloidosis developed after kidney transplantation. The underlying disease of our case was focal segmental glomerulosclerosis (FSGS), and was admitted to hospital for evaluation of proteinuria developed 2 years after kidney transplantation. The patient was initially diagnosed as recurrent FSGS on light microscopy. But, electron microscopic finding was suggestive of amyloidosis and systemic evaluation was consistent with systemic AL amyloidosis. This case provides the importance of differential diagnosis of proteinuria in kidney transplant recipients.