Infliximab for Drug induced Acute Interstitial Nephritis

Acute interstitial nephritis (AIN) is a frequent cause of acute kidney injury and is commonly drug induced.Corticosteroids are widely used for treatment; however, outcomes in cases with incomplete response or steroid intolerance remain uncertain, and evidence guiding second-line therapy is limited.We report a case of a 75-year-old man with biopsy-proven severe drug-induced AIN with superimposed oxalate nephropathy who developed dialysis-dependent acute kidney injury.The offending agent was discontinued, and high-dose corticosteroids were initiated but subsequently tapered due to intolerance.In the setting of persistent dialysis dependence and steroid-induced neuropsychiatric toxicity, infliximab was administered during prednisone taper.Renal recovery subsequently occurred, dialysis was discontinued, and the urinary retinol-binding protein-to-creatinine ratio declined in parallel with clinical improvement.Although causality cannot be established, this case raises the possibility that TNF- blockade may warrant further investigation in selected patients with severe drug-induced AIN complicated by steroid intolerance.Urinary tubular biomarkers may provide supportive information regarding tubular injury but require further validation.