title: Human herpesvirus-6 and acute liver failure.
abstract: BACKGROUND
  In patients with acute liver failure (ALF) of unknown cause, viral infections are believed to be involved. This study investigates the involvement of human herpesvirus-6 (HHV-6).
  
  
  METHODS
  Thirty-two patients with ALF who underwent transplantations during a 6-year period were studied for viruses in biopsies from their explanted livers. Non-A to non-E hepatitis (unknown) ALF was the reason for transplantation in 15 patients, and another 17 patients with a known disease from the same time period served as controls. The explanted livers were examined for hepatitis viruses and other possible viral agents. HHV-6 antigens were demonstrated in the livers and blood mononuclear cells by immunoperoxidase staining.
  
  
  RESULTS
  Of the 15 patients with ALF of unknown cause, 12 (80%) demonstrated HHV-6 antigens in the liver. Most of these patients (10/12) also demonstrated HHV-6 antigenemia. The predominant histologic finding of HHV-6 infection was moderate to severe portal lymphocytic infiltration. HHV-6 was found in 4 of 17 control patients, and cytomegalovirus was found in 2 of 17 control patients (in the blood and explanted liver). No other viruses were found in the livers of the patients with ALF.
  
  
  CONCLUSIONS
  HHV-6 was found in most explanted livers of patients with ALF of unknown cause. HHV-6 antigenemia was associated with HHV-6 antigens in the liver. Only a few control patients displayed HHV-6 in the liver. These observations indicate that HHV-6 may be one of the causes of ALF.
authors.affiliation: Transplantation and Liver Surgery Unit, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Maiju
authors.initials: M
authors.lastname: Härmä
authors.forename: Krister
authors.initials: K
authors.lastname: Höckerstedt
authors.forename: Irmeli
authors.initials: I
authors.lastname: Lautenschlager
mesh_terms: D000956:Antigens, Viral / Q000032:analysis / Q000097:blood; D003587:Cytomegalovirus / Q000302:isolation & purification; D005260:Female; D015654:Herpesvirus 6, Human / Q000302:isolation & purification; D006801:Humans; D008099:Liver / Q000276:immunology / Q000821:virology; D017114:Liver Failure, Acute / Q000209:etiology*; D016031:Liver Transplantation; D008297:Male; D019349:Roseolovirus Infections / Q000150:complications*
chemical_list: D000956:Antigens, Viral