title: Association of autoimmune pancreatitis with cytotoxic T-lymphocyte antigen 4 gene polymorphisms in Japanese patients.
abstract: OBJECTIVE
  Autoimmune pancreatitis (AIP) is characterized by high serum IgG4 concentrations, lymphoplasmacytic inflammation, and a favorable response to corticosteroid treatment. Although the HLA DRB1*0405-DQB1*0401 haplotype and Fc receptor-like 3 polymorphisms have been associated with AIP, the role of other genetic factors is largely unknown. As cytotoxic T-lymphocyte antigen 4 (CTLA4) polymorphisms have recently been linked with several autoimmune diseases, we sought to determine if CTLA4 polymorphisms and serum sCTLA4 levels were associated with AIP as well.
  
  
  METHODS
  Five CTLA4 polymorphisms, located at -1722, -658, and -318 in the promoter, +49 in exon 1, and +6230 in the 3' untranslated region, were genotyped in 59 patients with AIP and 102 healthy subjects. Serum sCTLA4 levels were also determined in cohorts of 52 patients and 32 controls.
  
  
  RESULTS
  Compared with healthy subjects, we found a significant increase in the +6230 G/G genotype (64%vs 42%, odds ratio [OR] 2.48, P= 0.011) in AIP patients. Haplotype 2, which had the +6230A, was associated with AIP resistance (OR 0.49, P= 0.011). The +49A/A and +6230A/A genotypes were associated with an enhanced risk of relapse (OR 5.45, P= 0.038 and OR 12.66, P= 0.022). Additionally, median serum sCTLA4 levels were significantly higher in patients with AIP (8.9 ng/mL) compared with healthy subjects (2.9 ng/mL, P < 0.001). The +6230 G/A polymorphism did not influence sCTLA4 levels in AIP patients.
  
  
  CONCLUSIONS
  Our findings suggest that AIP is associated with a genetic polymorphism in CTLA4 and is positively correlated with serum sCTLA4 levels.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Takeji
authors.initials: T
authors.lastname: Umemura
authors.forename: Masao
authors.initials: M
authors.lastname: Ota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hamano
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Katsuyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Muraki
authors.forename: Norikazu
authors.initials: N
authors.lastname: Arakura
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawa
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood / Q000235:genetics*; D000943:Antigens, Differentiation / Q000097:blood / Q000235:genetics*; D001327:Autoimmune Diseases / Q000235:genetics* / Q000276:immunology; D060908:CTLA-4 Antigen; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D050500:Pancreatitis, Chronic / Q000235:genetics* / Q000276:immunology; D020641:Polymorphism, Single Nucleotide; D012008:Recurrence
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D005819:Genetic Markers; D007074:Immunoglobulin G