Table 2.
Secondary allotransplantation after xeno-sensitization in concordant NHP models
| Author | Year | Recipient (n) |
Primary xenograft donor |
Primary organ/tissue /cell |
Graft survival |
Secondary allograft donor (n) |
Secondary organ/tissue /cell |
Graft survival |
REF. |
|---|---|---|---|---|---|---|---|---|---|
| Alonso de Begona et al (a) | 1992 | Baboon (n=5) | African green monkey | Heart | 5–65 days | Baboon (n=5) | Heart | 10≥198 days | 10 |
| Ye et al (b) | 1995 | Baboon (n=6) | African green monkey | Liver | 10–120 days | Baboon (n=1) | Heart | >30 days | 4 |
| Michler et al (c) | 1996 | Baboon (n=4) | Cynomolgus monkey | Heart | >14 days | Baboon (n=4) | Heart | >56 days | 11 |
Two baboons with allografts survived for 164 and 198 days (until they were euthanized) without evidence of rejection.
The baboon in which the xenograft survived 120 days received a secondary baboon heart allotransplant, which was followed for >30 days without features of rejection (until elective euthanasia). At the time of allotransplantation, a lymphocytotoxicity assay carried out with serum from the recipient and cells from the baboon heart donor was negative.
Despite the fact that, after xenotransplantation, 50% of the baboons developed cytotoxic antibodies against the MHC class II-like antigens expressed by lymphocytes of more than half of a panel of 12 baboons, neither the presence of these antibodies nor the severity of the prior xenograft rejection impacted the histology of allograft rejection. When T cell lines were developed from T cells isolated from xenograft biopsies, none demonstrated cell-mediated proliferative or cytotoxic activity against cells from the secondary allograft donor. These data suggested that a prior concordant xenograft was not detrimental to a subsequent allograft.