A Case of Amyloid Arthritis With Increased Amyloid Deposition of Both β2‐Microglobulin and Transthyretin Before Reinitiating Dialysis Long After Kidney Transplantation

We herein present the first reported case of a 65-year-old man on haemodialysis who developed amyloid arthritis involving both β2-microglobulin and transthyretin. He had begun haemodialysis 46 years prior, and 22 years later, he developed carpal tunnel syndrome due to dialysis-related amyloidosis. After 29 years on haemodialysis, he received a deceased-donor kidney transplant, allowing him to discontinue dialysis. Fourteen years post-transplant, he was diagnosed with wild-type transthyretin cardiac amyloidosis. Seventeen years after the kidney transplant, he had to resume haemodialysis because of kidney dysfunction and presented with persistent fever. Computed tomography revealed increased amyloid deposits in the joints compared with the time of his transplant. A biopsy of the shoulder joint confirmed the presence of amyloid deposits positive for both β2-microglobulin and transthyretin as determined by immunostaining and mass spectrometry. The patient was treated with glucocorticoids, tafamidis meglumine and β2-microglobulin adsorption therapy, leading to improvement in his symptoms. This case highlights that amyloid deposition can progress due to kidney dysfunction, even during periods without dialysis following a kidney transplant, and underscores the need to consider transthyretin amyloid deposition in patients undergoing dialysis.