Heart Transplant Research Today is a free monthly online journal that collates and summarizes the latest research about Heart Transplant, including details on risks, prognosis, procedure, surgery, organ donation.

Cardiac xenotransplantation: recent preclinical progress with 3-month median survival.

McGregor CG, Davies WR, Oi K, Teotia SS, Schirmer JM, Risdahl JM, Tazelaar HD, Kremers WK, Walker RC, Byrne GW, Logan JS

Division of Cardiovascular Surgery, Department of Surgery, Mayo Clinic, Rochester, Minn 55905, USA. mcgregor.christopher@mayo.edu

OBJECTIVES: Transplantation is limited by a lack of human organ donors. Organs derived from animals, most likely the pig, represent a potential solution to this problem. For the heart, 90-day median graft survival of life-supporting pig hearts transplanted to nonhuman primates has been considered a reasonable standard for entry into the clinical arena. Overcoming the immune barrier to successful cardiac xenotransplantation is most appropriately first explored with the non-life-supporting heterotopic model. METHODS: We performed a series of 7 heterotopic heart transplantations from CD46 transgenic pigs to baboons using a combination of therapeutic agents largely targeted at controlling the synthesis of anti-pig antibodies. Rituximab (anti-CD20) and Thymoglobulin (rabbit antithymocyte globulin [ATG]; SangStat Medical Corp, Fremont, Calif) were used as induction therapy. Baseline immunosuppression consisted of splenectomy, tacrolimus, sirolimus, steroids, and TPC (an anti-Gal antibody therapeutic). Rejection events were not treated. RESULTS: By using Kaplan-Meier analysis, median graft survival was 96 days (range, 15-137 days; 95% confidence interval, 38-99 days). Only 2 grafts were lost as a result of rejection, as defined by cessation of graft palpation. There was no evidence of a consumptive coagulopathy, infectious complications were treatable, and no posttransplantation lymphoproliferative disorders occurred. No cellular infiltration was observed. CONCLUSIONS: This study reports the longest median survival to date (96 days) of pig hearts transplanted heterotopically into baboons. Duplication of these results in the orthotopic life-supporting position could bring cardiac xenotransplantation to the threshold of clinical application.

Published 12 September 2005 in J Thorac Cardiovasc Surg, 130(3): 844-51.
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