Syngeneic living-donor liver transplantation without the use of immunosuppression.

Transplantation between monozygotic twins has been successfully performed using the kidney, small intestine, and pancreas. Identical HLA matching has enabled these individuals to be transplanted without the need for immunosuppressive medication. Liver transplantation without immunosuppression would lessen the risk of recurrent viral hepatitis and eliminate much of the morbidity associated with long-term use of immunosuppressive medication. Living-donor liver transplantation (LDLT) has been performed with increasing success in recent years without an opportunity arising to use a monozygotic twin as a donor. We report 2 cases of LDLT between identical twins wherein perfect haploidentity has allowed these recipients to be transplanted without the need for immunosuppression. Although HLA matched genotypically, there may be differences in anatomy between donor and recipient. Mild liver chemistry test abnormalities may occur after transplant despite the absence of immunosuppression.