title: Intrahepatic natural killer cell activation, but not function, is associated with HBsAg levels in patients with HBeAg-negative chronic hepatitis B.
abstract: OBJECTIVE
  Natural killer (NK) cells play an important role in the immune response to viruses. As the hepatitis B virus (HBV) replicates in hepatocytes, examination of the liver of chronic hepatitis B (CHB) patients is crucial to better understand the role of NK cells in HBV. HBeAg-negative CHB differs in many aspects from HBeAg-positive CHB, and until now little is known about the intrahepatic NK cell response in HBeAg-negative patients. Intrahepatic immune control might be different in HBeAg-negative as compared with HBeAg-positive patients.
  
  
  METHODS
  Liver NK cells were investigated in 21 HBeAg-positive and 35 HBeAg-negative CHB patients. Biopsy specimens were processed for routine histopathology and staging according to Ishak scores. Intrahepatic and blood NK cell frequencies, activation status and function of NK cells were analysed by flow cytometry.
  
  
  RESULTS
  In HBeAg-negative CHB patients, compared to blood, liver NK cells displayed a more activated phenotype and stimulation further increased the activation status, but production of IFN-γ was markedly less. There was no difference with HBeAg-positive CHB. Only in HBeAg-negative CHB, but not in HBeAg-positive CHB, NK cell activation was inversely correlated with HBsAg levels.
  
  
  CONCLUSIONS
  The present study indicates that liver NK cells of CHB have a higher activation status compared to blood. However, they are not capable to increase cytokine production above levels reached by activated blood NK cells. In HBeAg-negative CHB, the levels of HBsAg may contribute to the incapacity of activated liver NK cells to increase cytokine production.
authors.affiliation: Liver Unit, Department of Gastroenterology and Hepatology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Eric T T L
authors.initials: ET
authors.lastname: Tjwa
authors.forename: Roeland
authors.initials: R
authors.lastname: Zoutendijk
authors.forename: Gertine W
authors.initials: GW
authors.lastname: van Oord
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Biesta
authors.forename: Joanne
authors.initials: J
authors.lastname: Verheij
authors.forename: Harry L A
authors.initials: HL
authors.lastname: Janssen
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Woltman
authors.forename: Andre
authors.initials: A
authors.lastname: Boonstra
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008099:Liver / Q000276:immunology / Q000473:pathology*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; C573415:IFNG protein, human; D007371:Interferon-gamma
keywords: HBV; NK cells; innate immunity; liver; viral hepatitis