Allogeneic fetal small bowel graft in pigs treated with cyclosporin A

The functional integrity of transplanted fetal intestine was proven in rodents. The authors examined the morphology and development of intraperitoneally transplanted fetal intestine under cyclosporin A (CsA) monotherapy in a large mammal.

Allogeneic fetal intestinal grafts were transplanted intraperitoneally in pigs. The graft was wrapped in omentum. Thirteen recipients received grafts harvested at 60 days of gestation and 5 at 105 days of gestation. All recipients received 25 mg/kg/d CsA. CsA blood levels were measured at the end of the study. The development of the grafts was assessed by inspection and histology studying revascularization, maturation, and immune rejection.

All grafts developed neovascularization. The intestinal wall in the 105-day-old group was thick enough to lead to complete mucosal destruction, whereas the 60-day-old group showed viable mucosa. All grafts induced an immune rejection. This immune response was correlated with the CsA blood level. The graft was destroyed within 15 days when CsA trough level was below 70 ng/mL, had a subacute rejection with villi atrophy when CsA trough level ranged from 70 to 150 ng/mL, and had a good appearance in spite of mild blunting of villi when CsA trough level was over 150 ng/mL.

Allogeneic fetal intestinal transplantation from 60-day-old embryos in pig achieved successful graft.