title: Atrophic hepatocytes express keratin 7 in ischemia-associated liver lesions.
abstract: OBJECTIVE
  To investigate atrophic parenchymal changes in ischemic liver conditions.
  
  
  METHODS
  We studied 18 cases of hepatic lesions with atrophic changes due to altered blood flow (hepatic venous congestion n=15 including 4 cases with additional nodular regenerative hyperplasia-NRH, NRH n=1, and antiphospholipid syndrome with patchy parenchymal atrophy n=2). Metaplastic hepatocellular changes, hepatocyte proliferation, hepatic stellate cell (HSC) activation, and sinusoidal capillarization were examined immunohistochemically with antibodies to keratins (K) 7 and 19, Ki67, αSMA and CD34, respectively.
  
  
  RESULTS
  K7 was positive and K19 was negative in zone 3 atrophic hepatocytes in venous congestion and in areas of plate atrophy, as well as in congested or compressed sites in NRH. Sinusoidal CD34-positivity indicating capillarization accompanied K7 immunoexpression. Masson trichrome revealed sinusoidal fibrosis to be restricted in atrophic areas, usually mild and in 7 cases focally dense. αSMA expression expanded beyond K7-positive areas. Ki67 was negative in K7-positive hepatocytes.
  
  
  CONCLUSIONS
  Ischemic parenchymal changes are characterized by hepatocyte K7 immunoexpression, sinusoidal capillarization, HSC activation and lack of cellular proliferation, indicating an early reaction of the major liver parenchyma cellular components creating a more resistant microenvironment. These phenotypic alterations may prove valuable in the discrimination of ischemic liver lesions.
authors.affiliation: First Department of Pathology, Medical School, National and Kapodistrian University of Athens, Athens, Greece. jokadelladetsima@hotmail.com.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Delladetsima
authors.affiliation: First Department of Pathology, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Stratigoula
authors.initials: S
authors.lastname: Sakellariou
authors.affiliation: First Department of Pathology, Medical School, National and Kapodistrian University of Athens, Athens, Greece.|Institute of Pathology and Molecular Pathology, Helios Klinikum Wuppertal, Germany.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Kokkori
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, UK.|Laboratory of Histology-Embryology, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Dina
authors.initials: D
authors.lastname: Tiniakos
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D005260:Female; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007511:Ischemia / Q000150:complications / Q000473:pathology*; D053552:Keratin-7 / Q000032:analysis / Q000096:biosynthesis*; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008107:Liver Diseases / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers; C507497:KRT7 protein, human; D053552:Keratin-7