A Systematic Review of Treatment for Acute Interstitial Nephritis

Acute interstitial nephritis (AIN) is a common cause of acute kidney injury. It is characterized by tubular inflammation with eosinophils histologically. The mainstay treatment for AIN includes early diagnosis; underlying infection or systemic disease treatment; cessation of the offending agent; and corticosteroid therapy, when indicated. This systematic review aims to evaluate the efficacy and safety of pharmacotherapy treatments for AIN by assessing treatment outcomes and adverse effects.

PubMed, Embase, Cochrane Library, and other major databases were systematically searched in June 2024 after registration with the International Prospective Register of Systematic Reviews. Manual searches of the references in relevant articles were conducted. Studies focusing on the treatment of AIN cases that were diagnosed histologically were included. A fixed-effects meta-analysis and meta-regression were performed using Stata SE 16.

A total of 3597 articles were eligible for screening. Twenty-three articles were included in the systematic review. There were 3 randomized controlled trials, 4 case series, and 16 retrospective cohort studies. Corticosteroids were the primary treatment in most of the studies, with 1 study evaluating the use of mycophenolate mofetil (MMF) in steroid-refractory patients. A meta-analysis of 3 studies showed that prednisolone use improved renal outcomes. There was significant variability across studies in dosing, treatment duration, and timing of initiation. Adverse events associated with corticosteroids were likely underreported.

Consistent evidence supporting the use of corticosteroids for treating AIN needs to be more comprehensive. There needs to be a clear consensus on the optimal treatment regimen. High-quality randomized controlled trials are required to help establish evidence-based guidelines for treating AIN.