Amyloidosis is characterized by extracellular deposition of protein fibrils in one or multiple organs. AA amyloidosis is secondarily occurred to be related with chronic infections or inflammatory diseases. We report a 67-year-old man suffered from secondary AA amyloidosis related with chronic Clostridium difficile colitis after repeated total hip replacement surgery. Infection control is the most important treatment of AA amyloidosis secondary to chronic infection. However, the patient's C. difficile colitis was not controlled well, eventually toxic megacolon with sepsis was developed. Consequently, he had to take total colectomy, but he expired with multi-organ failures. We suggested that early surgical procedure might be one option for intractable C. difficile colitis complicated with secondary amyloidosis.

Primary amyloidosis has unfavorable prognosis, particularly with organ involvement. Here, we report a case of clinical remission of renal amyloidosis after autologous hematopoietic cell transplantation. A 51-year-old female patient visited our hospital due to generalized edema. Initial evaluation showed hyperlipidemia, hypoalbuminemia, and heavy proteinuria, which were consistent with nephrotic syndrome. However, IgM lamda type monoclonal gammopathy was detected in serum and urine electrophoresis studies. Renal biopsy showed Congo red-positive amyloid deposition in mesangial area, glomerular capillary walls, and arterioles and amyloid fibers were confirmed by electron microscopy. Immunohistochemial study of the biopsy tissue demonstrated systemic light-chain amyloidosis (AL amyloidosis). Multiple myeloma was not evident on bone marrow examination. She received autologous hematopoietic cell transplantation after high dose melphalan treatment. Complete remissions were achieved after the treatment, respectively. Our findings suggest the potential role of autologous peripheral blood stem cell transplantation in treatment of AL amyloidosis.