Acute kidney injury in interstitial nephritis

The purpose of this review is to describe the most common causes of acute interstitial nephritis (AIN), the diagnostic work-up and the therapeutic management.

Several case series and registries have found an increasing incidence of AIN, especially among older patients. Drug-induced AIN still represents the most common cause. Early withdrawal of the culprit drug together with corticosteroid therapy remain the mainstay of treatment, although recent studies have shown that prolonged treatment beyond 8 weeks does not further improve kidney function recovery.

AIN is a common cause of acute kidney injury, and therefore, physicians should suspect this entity especially in patients exposed to multiple medications. While immune-allergic reaction to numerous drugs is the most common cause of AIN, other underlying systemic diseases may also be involved, and therefore, every patient should undergo a complete diagnostic evaluation. Kidney biopsy provides the definitive diagnosis of AIN, and certain histologic features may help to identify the underlying condition. In drug-induced AIN, an early discontinuation of the culprit drug is the mainstay of therapy, and unless a rapid recovery of kidney function is observed, a course of glucocorticoid therapy should be initiated.