title: Advanced histology and impaired liver regeneration are associated with disease severity in acute-onset autoimmune hepatitis.
abstract: OBJECTIVE
  Some cases of acute-onset autoimmune hepatitis (AIH) develop into severe or fulminant forms showing massive/submassive hepatic necrosis, and have a poor prognosis. The pathological features of acute-onset AIH remain uncertain. Ductular (intermediate) hepatocytes after massive/submassive necrosis may serve as hepatic progenitor cells, and could be seen as cytokeratin 7 (CK7)-positive hepatocytes in immunohistochemistry. Therefore, the aim was to examine histological features to obtain a better evaluation of acute-onset AIH.
  
  
  METHODS
  The histological features of 27 clinically acute-onset AIH patients were examined by immunohistochemistry using CK7.
  
  
  RESULTS
  On staining for CK7, intermediate hepatocytes were less commonly present (P < 0.001) and ductular reactions were more commonly present (P < 0.001) in severe/fulminant patients than in non-severe ones. In severe and fulminant patients, intermediate hepatocytes and intralobular progenitor cells were more commonly present (P < 0.005 and P < 0.05, respectively) and ductular reactions were less commonly present (P = 0.007) in recovered patients than in dead ones. Severe patients had more clinically and histologically advanced disease.
  
  
  CONCLUSIONS
  Immunohistochemical evaluation using CK7 might be a useful tool for evaluating liver regeneration, and intermediate hepatocytes and progenitor cells might play an important role in liver regeneration after massive and submassive necrosis in acute-onset AIH.
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University Department of Pathology, Tokyo Women's Medical University, Yachiyo Medical Centre, Chiba, Japan. fujiwara-cib@umin.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakano
authors.forename: Shin
authors.initials: S
authors.lastname: Yasui
authors.forename: Koichiro
authors.initials: K
authors.lastname: Okitsu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yonemitsu
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis / Q000473:pathology*; D022781:Hepatocytes / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7 / Q000378:metabolism; D008099:Liver / Q000473:pathology; D008115:Liver Regeneration; D008297:Male; D008875:Middle Aged
chemical_list: D053552:Keratin-7