Differentiating etiologies of acute kidney injury (AKI) is critical in determining the course of care in clinical practice. For example, acute interstitial nephritis (AIN) requires withdrawal of the offending drug and immunosuppressive therapy, while acute tubular injury (ATI) does not have any disease-specific therapies. Failure to distinguish AIN from ATI in a timely manner can lead to kidney fibrosis and chronic kidney disease. In this review, we discuss current tests and novel biomarkers to distinguish ATI from AIN.
