Duration of Treatment with Corticosteroids and Recovery of Kidney Function in Acute Interstitial Nephritis

Abstract

Background and objectives Drug-induced acute interstitial nephritis represents an emerging cause of acute kidney disease, especially among polymedicated elderly patients. Although corticosteroids are frequently used, controversy exists about the timing of initiation, efficacy, safety, and duration of treatment.Design, setting, participants, & measurements We performed a retrospective study of 182 patients with biopsy-proven drug-induced acute interstitial nephritis from 13 Spanish centers. Exposure was defined as the length of corticosteroid treatment. The main outcome was the level of serum creatinine at month 6, with respect to baseline values. ResultsThe most common offending agents were nonsteroidal anti-inflammatory drugs (27%). In 30% of patients, the offending drug could not be identified. The median time to suspected drug withdrawal was 11 days (interquartile range, 5-22). All patients presented with acute kidney disease and were treated with corticosteroids. The mean initial dose of prednisone was 0.860.2 mg/kg per day. High-dose corticosteroid treatment was maintained for 2 weeks (interquartile range, 1-4). After 6 months, the mean recovered GFR was 34626 ml/min per 1.73 m 2 and ten patients required maintenance dialysis. Use of high-dose corticosteroids for 3 weeks or treatment duration .8 weeks were not associated with better recovery of kidney function. In the multivariable analysis, delayed onset of steroid treatment (odds ratio, 1.02; 95% confidence interval, 1.0 to 1.04) and the presence of interstitial fibrosis of .50% on the kidney biopsy specimen (odds ratio, 8.7; 95% confidence interval, 2.7 to 27.4) were both associated with serum creatinine level at month 6 of .75%, with respect to baseline values.Conclusions High-dose corticosteroid treatment for 3 weeks or prolonged treatment for .8 weeks were not associated with greater kidney function recovery in drug-induced acute interstitial nephritis. A delay in the initiation of corticosteroids resulted in worse recovery of kidney function.

Predicting outcome in acute interstitial nephritis: a case–series examining the importance of histological parameters

“…Tubular atrophy and interstitial fibrosis [which is highly correlated to TA ( R = 0.98)] are markers of chronic tubulointerstitial damage with recognised prognostic implications in a diverse range of conditions . Increasing severity of TA and interstitial fibrosis have been shown to be associated with poor renal outcomes in AIN . Our finding that TA score is a predictor of poor renal recovery is consistent with these studies.…”

“…More recent studies have largely focused on the potential influence of corticosteroid treatment in the management of AIN . However, Muriithi et al found that increased tubular atrophy (TA) correlated with a poor response to corticosteroids while, in a multicentre retrospective study of steroid‐treated AIN, the presence of >50% interstitial fibrosis was associated with a reduced likelihood of renal recovery …”

Acute Interstitial Nephritis and Checkpoint Inhibitor Therapy

“…If we do try to apply the lessons learned from druginduced AIN to the management of ICI-related AIN, then understanding the role of steroids is also important. Early steroid initiation in addition to drug withholding is recommended because delays are associated with poorer kidney outcomes (22,23). Therefore, we should strongly consider kidney biopsy when in doubt because delaying diagnosis may affect kidney recovery.…”

Management of Drug-Associated Acute Interstitial Nephritis

“…Few clinical trials are available to guide this aspect of AIN care: observational studies, case series, and case reports define the field. Although the literature is somewhat inconsistent, it does appear that corticosteroids favorably affect renal recovery in drug-associated AIN (5,6,11,12).…”