title: Clinical significance of immunoglobulin G4-associated autoimmune hepatitis.
abstract: BACKGROUND
  Immunoglobulin (Ig) G4-associated autoimmune hepatitis (AIH) is a recently identified and possibly new disease entity. However, the epidemiology and clinical features of IgG4-associated AIH remain uncertain. The aim of this study was to determine the prevalence and the clinical, serological, and histological characteristics of IgG4-associated AIH.
  
  
  METHODS
  We examined the clinical features, serum IgG4 concentration, liver biopsy histology, and IgG4-bearing plasma cell infiltration of 60 patients with type 1 AIH and 22 patients with autoimmune pancreatitis.
  
  
  RESULTS
  High serum IgG4 concentration (≥ 135 mg/dL) and IgG4-bearing plasma cell infiltration in the liver (≥ 10/high-power fields [HPFs]) were found in 2 of the 60 (3.3%) patients with type 1 AIH. These patients had high serum levels of IgE, giant cell change, and rosette formation in the liver. Although corticosteroid therapy reduced the serum IgG4 concentration and normalized liver enzymes and histology, one patient developed IgG4-related sclerosing cholangitis after 5 years of follow-up.
  
  
  CONCLUSIONS
  Because IgG4-associated AIH was found in over 3% of Japanese patients with type 1 AIH in our cohort, further studies are needed on this possible new disease entity and its impact on the diagnostic guidelines of AIH.
authors.affiliation: Division of Hepatology and Gastroenterology, Department of Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan. tumemura@shinshu-u.ac.jp
authors.forename: Takeji
authors.initials: T
authors.lastname: Umemura
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hamano
authors.forename: Satoru
authors.initials: S
authors.lastname: Joshita
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ichijo
authors.forename: Kaname
authors.initials: K
authors.lastname: Yoshizawa
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
authors.forename: Masao
authors.initials: M
authors.lastname: Ota
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawa
authors.forename: Yasuni
authors.initials: Y
authors.lastname: Nakanuma
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
mesh_terms: D015209:Cholangitis, Sclerosing / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D015726:Giant Cells / Q000378:metabolism; D005938:Glucocorticoids / Q000627:therapeutic use; D019693:Hepatitis, Autoimmune / Q000188:drug therapy / Q000453:epidemiology / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood*; D007564:Japan; D008099:Liver / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000378:metabolism; D015995:Prevalence
chemical_list: D005938:Glucocorticoids; D007074:Immunoglobulin G; D007073:Immunoglobulin E