title: Tubulointerstitial nephritis with uveitis in Chinese adults.
abstract: OBJECTIVE
  Tubulointerstitial nephritis and uveitis (TINU) syndrome is considered a rare cause of acute tubulointerstitial nephritis (ATIN) that is usually associated with renal recovery. This study sought to investigate the diagnosis, prognosis, and contributing factors of TINU syndrome using a large cohort of patients with prospective follow-up.
  
  
  METHODS
  This study included patients with TINU syndrome from a prospective cohort of patients with ATIN from 2007 to 2012. Clinical-pathologic data were collected at biopsy and autoantibodies against modified C-reactive protein (mCRP-Ab) were measured. Serum levels and renal tissue expression of Kreb von den Lunge-6 were also detected. Independent risk factors for poor renal outcome at 12 months and late-onset uveitis were analyzed.
  
  
  RESULTS
  Thirty-one patients (28%) with biopsy-proven ATIN were classified as having TINU syndrome. Of these patients, 18 (58%) developed late-onset uveitis and were misdiagnosed as having drug-induced ATIN at the time of biopsy. An abnormal level of mCRP-Ab was an independent risk factor for late-onset uveitis (odds ratio, 14.7; 95% confidence interval, 3.4 to 64.0). Patients with TINU syndrome and drug-induced ATIN had comparable levels of Kreb von den Lunge-6 in both serum and renal tissues. Ninety-two percent of patients developed stage 3-4 CKD and/or tubular dysfunction by 12 months postbiopsy. Age, serum creatine level, erythrocyte sedimentation rate, and the presence of concomitant thyroid disease or leukocyturia were related to poor renal outcome. Relapse was seen in 36% (11 of 31) of patients and potentiated poor renal outcome.
  
  
  CONCLUSIONS
  The diagnosis of TINU syndrome can be missed in a large fraction of patients with ATIN because uveitis can present well after the onset of tubulointerstitial nephritis. Elevated mCRP-Ab levels may be useful in predicting late-onset uveitis TINU syndrome. Unfortunately, patients with TINU tended to have frequent relapses and most patients had incomplete renal recovery. Long-term follow-up is needed to prevent misdiagnosis and properly manage TINU syndrome.
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Peking University Institute of Nephrology, Beijing, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Su
authors.forename: Rong
authors.initials: R
authors.lastname: Chu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Yang
mesh_terms: D000328:Adult; D000367:Age Factors; D044466:Asian People; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002097:C-Reactive Protein / Q000276:immunology; D002681:China / Q000453:epidemiology; D003951:Diagnostic Errors; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood; D009395:Nephritis, Interstitial / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000628:therapy; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014605:Uveitis / Q000097:blood / Q000175:diagnosis / Q000208:ethnology / Q000628:therapy
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1; D002097:C-Reactive Protein