1. ¹Hospital 12 de Octubre, Madrid, Spain
2. ²Hospital Ramón y Cajal, Madrid, Spain
3. ³Hospital La Paz, Madrid, Spain
4. ⁴Hospital Príncipe de Asturias, Madrid, Spain
5. ⁵Hospital de la Princesa, Madrid, Spain
6. ⁶Hospital del Aire, Madrid, Spain
7. ⁷Clínica Ruber, Madrid, Spain
8. ⁸Hospital de Getafe, Madrid, Spain
9. ⁹Hospital Severo Ochoa, Madrid, Spain
10. ¹⁰Hospital Gregorio Marañón, Madrid, Spain

Correspondence: M Praga, Servicio de Nefrología, Hospital 12 de Octubre, Avda de Córdoba s/n, Madrid 28041, Spain. E-mail: mpragat@senefro.org

Received 20 June 2007; Revised 17 September 2007; Accepted 30 October 2007; Published online 9 January 2008.

Abstract

The role of steroid treatment in drug-induced acute interstitial nephritis (DI-AIN) is controversial. We performed a multicenter retrospective study to determine the influence of steroids in 61 patients with biopsy-proven DI-AIN, 52 of whom were treated with steroids. The responsible drugs were antibiotics (56%), non-steroidal anti-inflammatory drugs (37%) or other drugs. The final serum creatinine was significantly lower in treated patients while almost half of untreated patients remained on chronic dialysis. Among treated patients, over half showed a complete recovery of baseline renal function, whereas the rest remained in renal failure. There were no significant initial differences between these two subgroups in terms of duration or dosage of steroids. After withdrawal of the presumed causative drug, we found that when steroid treatment was delayed (by an average of 34 days) renal function did not return to baseline levels compared to those who received steroid treatment within the first 2 weeks after withdrawal of the offending agent. We found a significant correlation between the delay in steroid treatment and the final serum creatinine. Renal biopsies, including three patients who underwent a second biopsy, showed a progression of interstitial fibrosis related to the delay in steroid treatment. Our study shows that steroids should be started promptly after diagnosis of DI-AIN to avoid subsequent interstitial fibrosis and an incomplete recovery of renal function.