Heart xenograft survival with chimeric pig donors and modest immune suppression.

Objective: To assess the use of donor pigs with cellular chimerism for prevention of acute rejection with modest immune suppression. The clinical use of pig organ xenografts is currently precluded by severe acute rejection, which resists standard immune suppression.

Summary Background Data: For long-term survival of pig organ xenografts, immune suppression significantly greater than used with allografts would currently be necessary, leaving the recipient immune deficient and at increased risk for infections.

Pre-transplant analysis of accommodation in donor pigs.

Accommodation could lead to xenograft acceptance without the need for severe immune suppression. Generally graft accommodation is appreciated in the sensitized recipient, after transplantation. By inducing accommodation in chimeric donors, however, the risk and cost of inducing accommodation in the recipient would be reduced.