Systemic AA amyloidosis with amyloid deposition in the peritoneum at the time of initiating peritoneal dialysis.

Amyloidosis is characterized by the deposition of insoluble amyloid fibrils formed by disease-specific precursor proteins in the extracellular interstitium of various organs throughout the body, resulting in organ damage. Patients with amyloidosis often develop end-stage kidney disease (ESKD), which can be managed with dialysis or kidney transplantation. Peritoneal dialysis (PD) is advantageous over hemodialysis (HD) in managing the circulatory dynamics and removing the precursor proteins of amyloid fibrils. However, the clinical course of PD using an amyloid-deposited peritoneum has not been reported. In this paper, we describe a rare case of systemic AA amyloidosis with amyloid deposition in the peritoneum at the beginning of PD. The peritoneal equilibrium test (PET) at PD initiation revealed a high transport rate. The dialysis solution was temporarily changed to a high-glucose concentration peritoneal dialysate, and a weekly extracorporeal ultrafiltration method was added. The patient continued with PD treatment without any complications. The PET category changed from "high" to "high average" during the subsequent PD treatment course. The serum amyloid A levels improved post-nephrectomy and remained in the normal range. Amyloid A was not detected in the dialysate drainage. In conclusion, the amyloid-deposited peritoneum has no uniform effect on the clinical course of PD. Moreover, amyloidosis therapy can alter the peritoneal function with amyloid deposition. However, future studies should investigate the exact mechanism of the alteration of peritoneal function with amyloidosis therapy.