title: Intracellular balance of oxidative stress and cytoprotective molecules in damaged interlobular bile ducts in autoimmune hepatitis and primary biliary cirrhosis: In situ detection of 8-hydroxydeoxyguanosine and glutathione-S-transferase-pi.
abstract: OBJECTIVE
  Bile duct injury has been thought to be absent in autoimmune hepatitis (AIH), but recent studies have indicated that AIH patients do have bile duct injury. In this study, the intracellular balance of oxidative stress and cytoprotection in biliary epithelial cells was investigated to clarify the pathogenesis of bile duct injury in AIH.
  
  
  METHODS
  The intracellular status of oxidative DNA damage caused by oxidative stress and glutathione, an endogenous cytoprotective molecule, were examined in patients with AIH, primary biliary cirrhosis (PBC), and normal controls by immunostaining of 8-hydroxydeoxyguanosine (8-OHdG) and glutathione-S-transferase-pi.
  
  
  RESULTS
  Immunohistochemically, 8-OHdG expression was detected as abundantly in the damaged bile ducts of AIH patients as in PBC patients. Moreover, in AIH, 8-OHdG expression was detected in damaged bile ducts more than in undamaged bile ducts. Glutathione-S-transferase-pi expression was relatively preserved in the damaged bile ducts of AIH patients compared to PBC patients, reflecting preservation of intracellular glutathione.
  
  
  CONCLUSIONS
  In AIH, oxidative stress and DNA damage may be involved in the pathogenesis of bile duct injury in a manner similar to that found in PBC. However, relatively preserved intracellular glutathione may play a key role in preventing progressive bile duct loss following bile duct injury in AIH.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University School of Medicine, Nagasaki, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kadokawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ohba
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Omagari
authors.forename: Shiho
authors.initials: S
authors.lastname: Akazawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Hayashida
authors.forename: Ken
authors.initials: K
authors.lastname: Ohnita
authors.forename: Fuminao
authors.initials: F
authors.lastname: Takeshima
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mizuta
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno