Edoxaban-induced acute interstitial nephritis.

A 76 year-old man with no specific medical history was diagnosed with atrial fibrillation and was started on edoxaban. Seven days after starting edoxaban, renal dysfunction was observed. He was suspected of having anticoagulant-related nephropathy due to acute kidney injury that occurred after starting edoxaban, and a renal biopsy was performed on day 5 of the illness to confirm the diagnosis. The renal biopsy results showed no red blood cell casts in the renal tubules, and inflammatory cell infiltration of lymphocytes and plasma cells was found in the interstitium, leading to a diagnosis of acute interstitial nephritis. There were no findings suggestive of autoimmune disease, and a drug-induced lymphocyte stimulation test to edoxaban was positive, leading to a diagnosis of edoxaban-induced acute interstitial nephritis. In addition to anticoagulant-related nephropathy, drug-induced interstitial nephritis should be considered as a cause of acute kidney injury after initiation of anticoagulant drugs.