Effective antiplatelet therapy does not prolong transgenic pig to baboon cardiac xenograft survival.
BACKGROUND: Microvascular thrombosis is a prominent characteristic of delayed xenograft rejection, therefore the effects of antiplatelet therapy with aspirin and clopidogrel on long-term cardiac xenograft function was investigated in a heterotopic pig-to-baboon cardiac transplant model. METHODS: Donor hearts from human CD46 transgenic pigs were transplanted heterotopically to baboons. The recipients received immunosuppression that included tacrolimus, sirolimus, corticosteroids, anti-CD20 monoclonal antibody and TPC, an alpha-galactosyl-polyethylene glycol conjugate. In group 1 (n = 9) in addition to immunosuppression, the recipients received combination therapy consisting of aspirin (80 mg/day) and clopidogrel (75 mg/day) beginning 2 days after transplant and continuing until cessation of graft function. Antiaggregatory efficacy was evaluated by platelet aggregation assay. In group 2 (n = 9) antiplatelet drugs were not given. RESULTS: Functional assays confirmed inhibition of platelet aggregation in group 1 suggesting sufficient systemic effects of the treatment. However, anticoagulant therapy did not result in significant prolongation of xenograft function (group 1: median survival 22 days, range 15 to 30 days; group 2: median survival 15 days, range 4 to 53 days). Histologic analysis at rejection revealed no difference in the level of platelet containing thrombi between the groups. CONCLUSIONS: Inhibition of platelet aggregation by a combination of aspirin and clopidogrel did not have a significant impact on the length of xenograft survival or on the development of microvascular thrombosis in this pig-to-primate model.
|Title:||Effective antiplatelet therapy does not prolong transgenic pig to baboon cardiac xenograft survival.|
|Keywords:||Animals, Animals, Genetically Modified, Antigens, CD, Antigens, CD46, Aspirin, Graft Rejection, Graft Survival, Heart Transplantation, Humans, Membrane Glycoproteins, Papio anubis, Platelet Aggregation, Platelet Aggregation Inhibitors, Swine, Ticlopidine, Time Factors, Transplantation, Heterologous|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science
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