Acute kidney injury after treatment with arsenic trioxide.

All-trans retinoic acid (ATRA) and arsenic trioxide (ATO)-based therapy has become the standard of care in the treatment of acute promyelocytic leukemia (APL). While ATO nephrotoxicity has been rarely reported, data on the specific mechanisms and types of renal injury remain scarce. We present a case of acute kidney injury (AKI) superimposed on chronic kidney disease (CKD) induced by ATO therapy in a patient diagnosed with APL. Biopsy findings revealed acute interstitial nephritis on a background of IgA nephropathy. The AKI resolved after the discontinuation of ATO therapy and initiating steroid treatment. The kidney function remained stable at 6-month follow-up. This case highlights the potential renal complications associated with ATO therapy and highlights the importance of monitoring kidney function in patients undergoing this treatment.