title: Modified C-reactive protein might be a target autoantigen of TINU syndrome.
abstract: OBJECTIVE
  The cross-reactive antigen(s) of tubulointerstitial nephritis and uveitis (TINU) syndrome from renal tubulointerstitia and ocular tissue remain unidentified. The authors' recent study demonstrated that the presence of serum IgG autoantibodies against modified C-reactive protein (mCRP) was closely associated with the intensity of tubulointerstitial lesions in lupus nephritis. The study presented here investigates the possible role of IgG autoantibodies against mCRP in patients with TINU syndrome.
  
  
  METHODS
  mCRP autoantibodies were screened by ELISA with purified human C-reactive protein in 9 patients with TINU syndrome, 11 with drug-associated acute interstitial nephritis, 20 with IgA nephropathy, 19 with minimal change disease, 20 with ANCA-associated vasculitis, 6 with Sjogren's syndrome, and 12 with amyloidosis. mCRP expression was analyzed by immunohistochemistry in renal biopsy specimens from the 9 patients with TINU syndrome and 40 from disease controls. Frozen normal human kidney and iris were used to demonstrate co-localization of human IgG and mCRP from patients with TINU syndrome with laser scanning confocal microscopy.
  
  
  RESULTS
  The mCRP autoantibodies were detected in all nine patients with TINU syndrome, significantly higher than that of those with disease controls (P < 0.05). The renal histologic score of mCRP in TINU syndrome was significantly higher than that in disease controls (P < 0.05). The staining of mCRP and human IgG were co-localized in renal and ocular tissues.
  
  
  CONCLUSIONS
  It is concluded that mCRP might be a target autoantigen in TINU syndrome.
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital and Institute of Nephrology, Peking University Key Laboratory of Renal Disease, Ministry of Health of China, Peking, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tan
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Qu
authors.forename: Tao
authors.initials: T
authors.lastname: Su
authors.forename: Guang-Qun
authors.initials: GQ
authors.lastname: Xing
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Wu
authors.forename: Feng-Mei
authors.initials: FM
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D002097:C-Reactive Protein / Q000032:analysis / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000097:blood / Q000276:immunology; D014605:Uveitis / Q000097:blood / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; D002097:C-Reactive Protein
references.citation: Cell Death Differ. 2009 Dec;16(12):1630-40
references.pmid: 19680263
references.citation: Clin Immunol Immunopathol. 1988 Jul;48(1):95-107
references.pmid: 2454772
references.citation: Ophthalmology. 2007 May;114(5):995-9
references.pmid: 17383731
references.citation: Nephrol Dial Transplant. 1997 Jan;12(1):51-6
references.pmid: 9027773
references.citation: Invest Ophthalmol Vis Sci. 2006 Mar;47(3):1030-8
references.pmid: 16505038
references.citation: Nephrol Dial Transplant. 2008 Apr;23(4):1452-5
references.pmid: 18156461
references.citation: Kidney Int. 1974 Mar;5(3):187-95
references.pmid: 4362245
references.citation: Pediatrics. 2001 Jun;107(6):1443-6
references.pmid: 11389273
references.citation: Nephrol Dial Transplant. 1993;8(9):821-6
references.pmid: 8255514
references.citation: Autoimmunity. 1994;18(4):259-65
references.pmid: 7858111
references.citation: Nephrol Dial Transplant. 2008 Apr;23(4):1095-7
references.pmid: 18272778
references.citation: Arterioscler Thromb Vasc Biol. 2006 Apr;26(4):935-41
references.pmid: 16456095
references.citation: Pediatr Nephrol. 1991 Mar;5(2):232-4
references.pmid: 2031842
references.citation: Am J Med. 1975 Sep;59(3):325-33
references.pmid: 1163543
references.citation: J Exp Med. 1986 Jul 1;164(1):321-6
references.pmid: 3723078
references.citation: Kidney Int. 1999 Feb;55(2):713-23
references.pmid: 9987096
references.citation: Ann N Y Acad Sci. 2007 Jun;1108:227-39
references.pmid: 17899624
references.citation: Nephrol Dial Transplant. 2003 Nov;18(11):2300-7
references.pmid: 14551357
references.citation: Semin Immunopathol. 2008 Apr;30(2):85-95
references.pmid: 18299835
references.citation: Nephrology (Carlton). 2008 Feb;13(1):89
references.pmid: 18199112
references.citation: Cell Mol Immunol. 2008 Feb;5(1):9-21
references.pmid: 18318990
references.citation: Surv Ophthalmol. 2001 Nov-Dec;46(3):195-208
references.pmid: 11738428
references.citation: Nihon Jinzo Gakkai Shi. 1983 Aug;25(8):1027-34
references.pmid: 6668743
references.citation: Am J Med Sci. 2000 Feb;319(2):79-83
references.pmid: 10698090
references.citation: Circulation. 2003 Oct 21;108(16):1930-2
references.pmid: 14530191
references.citation: Eur J Immunol. 2003 Jan;33(1):152-61
references.pmid: 12594844