Drug-induced acute interstitial nephritis: A clinicopathological study and comparative trial of steroid regimens

Steroids are used in the management of drug-induced acute interstitial nephritis (AIN). The present study was undertaken to compare the efficacy of pulse methyl prednisolone with oral prednisolone in the treatment of drug-induced AIN. Patients with biopsy-proven AIN with a history of drug intake were randomized to oral prednisolone (Group 1) 1 mg/kg for 3 weeks or a pulse methyl prednisolone (Group II) 30 mg/kg for 3 days followed by oral prednisolone 1 mg/kg for 2 weeks, tapered over 3 weeks. Kidney biopsy scoring was done for interstitial edema, infiltration and tubular damage. The response was reported as complete remission (CR) (improvement in estimated glomerular filtration rate [eGFR] to ≥60 ml/min/1.73 m(2)), partial remission (PR) (improvement but eGFR <60 ml/min/1.73 m(2)) or resistance (no CR/PR). A total of 29 patients, Group I: 16 and Group II: 13 were studied. Offending drugs included nonsteroidal anti-inflammatory drugs, herbal drugs, antibiotics, diuretic, rifampicin and omeprazole. There was no difference in the baseline parameters between the two groups. The biopsy score in Groups I and II was 5.9 ± 1.1 and 5.1 ± 1.2, respectively. At 3 months in Group I, eight patients each (50%) achieved CR and PR. In Group II, 8 (61%) achieved CR and 5 (39%) PR. This was not significantly different. Percentage fall in serum creatinine at 1 week (56%) was higher in CR as compared to (42%) those with PR. (P = 0.14). Patients with neutrophil infiltration had higher CR compared to patients with no neutrophil infiltration (P = 0.01). Early steroid therapy, both oral and pulse steroid, is equally effective in achieving remission in drug-induced AIN.