Long-term survival of an allografted submandibular gland in a miniature swine model given immunosuppressant drugs

We used a model of allografts of submandibular glands in miniature swine to test the requirements of immunosuppressants for the survival of such grafts. Animals in the first group (n = 6) were given no immunosuppressant, and the submandibular glands were rejected within 7 days. Those in the low-dose group (n = 4) were treated with a low dose of cyclosporine, methylprednisolone, and azathioprine. The allografts were rejected on days 15, 17, 19, and 20. The animals in the high-dose group (n = 6) were treated with a high dose of cyclosporin, methylprednisolone, and azathioprine. Three allografts were rejected, on days 35, 48, and 60. One animal died from anaesthetic problems on day 30 after transplantation, and there were no signs of rejection in the allograft. The other two allografts survived for 100 days with secretory function and no signs of rejection. After we discontinued the immunosuppression on day 100, the two remaining allografts were rejected on days 121 and 128. Blood tests and biopsy specimens of the heart, lung, liver, and kidneys were normal in all animals that were given immunosuppressants. To our knowledge, this study is the first to describe long-term survival of allografted submandibular glands with secretory function in miniature swine.