Orthotopic liver transplantation. Various immunosuppressive regimens to improve survival

New approaches to immunosuppression, including cyclosporin A (Cy A), are being utilized to improve liver transplantation survival results. Donor livers from unrelated dogs were orthotopically transplanted to recipient animals, and only recipients that survived 2 or more days were included in this study. Animals were divided into the following groups: Group 1 (n = 6) received minimal immunosuppression (azathioprine) after orthotopic liver transplantation, Group 2 (n = 7) liver allografts were pretreated with Cy A (50 mg/L) prior to transplantation, and recipients were given minimal immunosuppression as in Group 1, Group 3 (n = 6) animals received azathioprine and methylprednisolone after transplantation, and Group 4 (n = 6) liver allograft recipients were given Cy A and methylprednisolone for 30 days followed by azathioprine. The improved survival seen in Groups 2, 3, and 4 in comparison with Group 1 (minimally immunosuppressed controls) indicates that graft pretreatment with Cy A or prophylactic Cy A administration (30 days), in conjunction with minimal immunosuppression, can prolong canine liver allograft survival as well as more standard regimens (Group 3). Therefore, it is possible that the use of steroids could be reduced or eliminated in hepatic transplantation with the application Cy A.