title: Hepatic progenitor cells in human liver cirrhosis: immunohistochemical, electron microscopic and immunofluorencence confocal microscopic findings.
abstract: OBJECTIVE
  To investigate whether hepatic progenitor cells (HPC), that reveal the features of oval cells in rodents and small epithelial cells (SEC) in certain human liver disease, were also found in human liver cirrhosis (HLC).
  
  
  METHODS
  Surgical liver specimens from 20 cases of hepatitis B virus-positive HLC (15 cases containing hepatocellular carcinoma) were investigated by light microscopic immunohistochemistry (LM-IHC). Among them specimens from 15 cases were investigated by electron microscopy (EM) and those from 5 cases by immunofluorencence confocal laser scanning microscopy (ICLSM). Antibodies against cytokeratin 7 and albumin were used and single and/or double labelling were performed respectively.
  
  
  RESULTS
  LM-IHC showed that at the margins of regenerating nodules and in the fibrous septae, a small number of cells in the proliferating bile ductules were positive for CK7 and albumin. At the EM level these HPC were morphologically similar to the SEC described previously, and also similar to the oval cells seen in experimental hepatocarcinogenesis. They were characterized by their small size, oval shape, a high nucleus/cytoplasm ratio, a low organelle content in cytoplasm, and existence of tonofilaments and intercellular junctions. ICLSM revealed that HPC expressed both cytokeratin 7 and albumin.
  
  
  CONCLUSIONS
  HPC with ultrastructural and immunophenotypical features of oval cells, i.e., hepatic stem cell-like cells as noted in other liver diseases, were found in HLC. These findings further support the hypothesis that bipotent hepatic stem cells, that may give rise to biliary epithelial cells and hepatocytes, exist in human livers.
authors.affiliation: Department of Pathology, Ruijin Hospital, Shanghai 2nd Medical University, Shanghai 200025, China. jcxiao@public4.sta.net.cn
authors.forename: Jia-Cheng
authors.initials: JC
authors.lastname: Xiao
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Jin
authors.forename: Peter
authors.initials: P
authors.lastname: Ruck
authors.forename: Anne
authors.initials: A
authors.lastname: Adam
authors.forename: Edwin
authors.initials: E
authors.lastname: Kaiserling
mesh_terms: D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000473:pathology*; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D013234:Stem Cells / Q000473:pathology* / Q000648:ultrastructure