title: Acute interstitial nephritis: clinical features and response to corticosteroid therapy.
abstract: BACKGROUND
  Acute interstitial nephritis (AIN) is a recognized cause of reversible acute renal failure characterized by the presence of an interstitial inflammatory cell infiltrate.
  
  
  METHODS
  In order to evaluate the clinical characteristics and management of this disorder, we performed a retrospective study of all cases of AIN found by reviewing 2598 native renal biopsies received at our institution over a 12 year period. Presenting clinical, laboratory and histological features were identified, as was clinical outcome with specific regard to corticosteroid therapy response.
  
  
  RESULTS
  AIN was found in 2.6% of native biopsies, and 10.3% of all biopsies performed in the setting of acute renal failure during the period analysed (n = 60). The incidence of AIN increased progressively over the period observed from 1 to 4% per annum. AIN was drug related in 92% of cases and appeared to be idiopathic in the remainder. The presenting symptoms included oliguria (51%), arthralgia (45%), fever (30%), rash (21%) and loin pain (21%). Median serum creatinine at presentation was 670 micromol/l [interquartile range (IQR) 431-1031] and 58% of cases required acute renal replacement therapy. Corticosteroid therapy was administered in 60% of cases. Serum creatinine at baseline was similar in the corticosteroid-treated and conservatively managed groups; 700 micromol/l (IQR 449-1031) vs 545 micromol/l (IQR 339-1110) P = 0.4. In this, the largest retrospective series to date, we did not detect a statistically significant difference in outcome, as determined by serum creatinine, between those patients who received corticosteroid therapy and those who did not, at 1, 6 and 12 months following presentation.
  
  
  CONCLUSIONS
  The results of this study do not support the routine administration of corticosteroid therapy in the management of AIN.
authors.affiliation: Renal Division, Brigham and Women's Hospital, 75 Frances Street, Boston, MA 02115, USA. mrclarkson@partners.org
authors.forename: Michael R
authors.initials: MR
authors.lastname: Clarkson
authors.forename: Louise
authors.initials: L
authors.lastname: Giblin
authors.forename: Fionnuala P
authors.initials: FP
authors.lastname: O'Connell
authors.forename: Patrick
authors.initials: P
authors.lastname: O'Kelly
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Walshe
authors.forename: Peter
authors.initials: P
authors.lastname: Conlon
authors.forename: Yvonne
authors.initials: Y
authors.lastname: O'Meara
authors.forename: Anthony
authors.initials: A
authors.lastname: Dormon
authors.forename: Eileen
authors.initials: E
authors.lastname: Campbell
authors.forename: John
authors.initials: J
authors.lastname: Donohoe
mesh_terms: D000208:Acute Disease; D000368:Aged; D001706:Biopsy; D003404:Creatinine / Q000097:blood; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D003404:Creatinine; D008775:Methylprednisolone