title: Ultrastructure of oval cells in children with chronic hepatitis B, with special emphasis on the stage of liver fibrosis: the first pediatric study.
abstract: OBJECTIVE
  To investigate the ultrastructure of oval cells in children with chronic hepatitis B, with special emphasis on their location in areas of collagen fibroplasia.
  
  
  METHODS
  Morphological investigations were conducted on biopsy material obtained from 40 children, aged 3-16 years with chronic hepatitis B. The stage of fibrosis was assessed histologically using the arbitrary semiquantitative numerical scoring system proposed by Ishak et al. The material for ultrastructural investigation was fixed in glutaraldehyde and paraformaldehyde and processed for transmission-electron microscopic analysis.
  
  
  RESULTS
  Ultrastructural examination of biopsy specimens obtained from children with chronic hepatitis B showed the presence of two types of oval cells, the hepatic progenitor cells and intermediate hepatic-like cells. These cells were present in the parenchyma and were seen most commonly in areas of intense periportal fibrosis (at least stage 2 according to Ishak et al) and in the vicinity of the limiting plate of the lobule. The activated nonparenchymal hepatic cells, i.e. transformed hepatic stellate cells and Kupffer cells were seen in close proximity to the intermediate hepatic-like cells.
  
  
  CONCLUSIONS
  We found a distinct relationship between the prevalence of oval cells (hepatic progenitor cells and intermediate hepatocyte-like cells) and fibrosis stage in pediatric patients with chronic hepatitis B.
authors.affiliation: Department of Clinical Pathomorphology, Medical University of Bialystok, Waszyngtona 13 Street, 15-269 Bialystok, Poland. mariasl@zeus.amb.edu.pl
authors.forename: Maria Elzbieta Sobaniec-Lotowska
authors.initials: ME
authors.lastname: Sobaniec-Lotowska
authors.forename: Joanna Maria
authors.initials: JM
authors.lastname: Lotowska
authors.forename: Dariusz Marek
authors.initials: DM
authors.lastname: Lebensztejn
mesh_terms: D000293:Adolescent; D001706:Biopsy; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000648:ultrastructure; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D019694:Hepatitis B, Chronic / Q000473:pathology*; D022781:Hepatocytes / Q000648:ultrastructure / Q000821:virology; D006801:Humans; D007728:Kupffer Cells / Q000648:ultrastructure / Q000821:virology; D008099:Liver / Q000473:pathology / Q000648:ultrastructure* / Q000821:virology*; D008103:Liver Cirrhosis / Q000473:pathology* / Q000821:virology*; D008297:Male; D013234:Stem Cells / Q000473:pathology / Q000648:ultrastructure* / Q000821:virology*
chemical_list: D003094:Collagen