60 - Acute Interstitial Nephritis

Abstract

Acute interstitial nephritis (AIN) is a rare cause of acute kidney injury (AKI) and is characterized by inflammatory infiltrates within the interstitium. AIN is most often induced by drugs, particularly antimicrobial agents, proton pump inhibitors, and nonsteroidal antiinflammatory drugs. The typical presentation is sudden impairment in kidney function associated with mild proteinuria and abnormal urinalysis in a patient with extrarenal symptoms consistent with a hypersensitivity reaction. However, the presentation is often incomplete, and AIN should be considered in any patient with unexplained AKI. AIN is diagnosed by renal biopsy. The mainstay of therapy is timely discontinuation of the causative agent. Although the benefits of corticosteroid therapy remain unproven, they appear to have a positive effect in some cases. Less often, AIN occurs during the course of an infectious disease, an autoimmune disease, or a malignancy, or appears idiopathic.