title: Epstein-Barr virus infection is associated with endothelial Bcl-2 expression in transplant liver allografts.
abstract: BACKGROUND
  In liver transplant recipients with Epstein-Barr virus (EBV) disease, we reported a low rate of acute rejection after stopping or markedly lowering immunosuppression. This observation led to the hypothesis that EBV, as a means of viral persistence, induces expression of antiapoptotic factors and these factors, in turn, confer protection to the transplanted organ. Bcl-2, an antiapoptotic factor induced by EBV in various host cells, is not normally expressed in the liver. We questioned whether bcl-2 is expressed in the transplanted liver and whether its expression is modified by EBV.
  
  
  METHODS
  Retrospective liver biopsy specimen from liver transplant patients diagnosed with EBV (n=12) were examined for the presence of bcl-2 by immunohistochemistry and compared with EBV (-) transplant (n=15), and nontransplant (n=13) livers.
  
  
  RESULTS
  The most significant finding was the presence of endothelial bcl-2 expression in the majority of EBV (+) transplant samples examined (67%) and its relative absence in the other two groups (P<0.005). There was also bcl-2 expression in the hepatocytes and lymphocytes of the majority of transplant liver samples, irrespective of EBV status.
  
  
  CONCLUSIONS
  We have identified a strong association between EBV infection and endothelial bcl-2 expression in transplant livers. We also found that transplantation, in itself, was associated with bcl-2 expression in the hepatocytes and lymphocytes of liver allografts.
authors.affiliation: Department of Surgery, Division of Multi-Organ Transplantation, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Millan
authors.forename: Y
authors.initials: Y
authors.lastname: Natkunam
authors.forename: R
authors.initials: R
authors.lastname: Clarke-Katzenberg
authors.forename: D
authors.initials: D
authors.lastname: Desai
authors.forename: W
authors.initials: W
authors.lastname: Prapong
authors.forename: S K
authors.initials: SK
authors.lastname: So
authors.forename: C O
authors.initials: CO
authors.lastname: Esquivel
authors.forename: R
authors.initials: R
authors.lastname: Sibley
authors.forename: C
authors.initials: C
authors.lastname: Ferran
authors.forename: O M
authors.initials: OM
authors.lastname: Martinez
mesh_terms: D004730:Endothelium, Vascular / Q000737:chemistry*; D020031:Epstein-Barr Virus Infections / Q000209:etiology*; D006084:Graft Rejection; D022781:Hepatocytes / Q000737:chemistry; D006801:Humans; D016031:Liver Transplantation / Q000009:adverse effects*; D008214:Lymphocytes / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D012189:Retrospective Studies; D014184:Transplantation, Homologous
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2