Immunopathology of liver transplantation.

Liver transplantation has become an accepted therapeutic modality for many patients with end-stage liver diseases. Compared to other solid organ allografts, the immunopathological mechanisms involved in the original disease, rejection reactions, and potentially recurrent original diseases are seemingly more complex. The spontaneous acceptance of animal liver grafts without immunosuppression, the induction of donor-specific tolerance after liver grafting, its seeming resistance to hyperacute or primary humoral rejection, the dualistic effect of major histocompatibility matching on graft survival, functional and immunohistopathologic aspects of rejection reactions, infections, and the complexities involved in analysis for the potential of recurrent disease are discussed. Although many issues remain unresolved, liver transplantation offers a unique opportunity for studying the role of the immune system in both transplantation biology and primary liver disease.