Epstein-Barr virus infection is associated with endothelial Bcl-2 expression in transplant liver allografts.
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.
Millan
M T
MT
Department of Surgery, Division of Multi-Organ Transplantation, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
Natkunam
Y
Y
Clarke-Katzenberg
R
R
Desai
D
D
Prapong
W
W
So
S K
SK
Esquivel
C O
CO
Sibley
R
R
Ferran
C
C
Martinez
O M
OM
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
D019253:Proto-Oncogene Proteins c-bcl-2