Efficacy of thalidomide as immunosuppressor in heterotopic heart transplantation.

BACKGROUND: Based on its anti-inflammatory and immunosuppressive effects, thalidomide has been used for the treatment of dermatologic diseases and of graft-versus-host reaction in patients submitted to bone marrow transplantation. The present study evaluated the immunosuppressive action of thalidomide alone or in combination with cyclosporine on the prevention of rejection of heterotopic cardiac allograft in rabbits. METHOD: Fifty rabbits were used, 25 of them as donors and 25 as receivers. The animals that received the graft were divided into five groups (n = 5): Group 1 (control)--non-immunosuppressed animals, Group 2 (animals immunosuppressed with cyclosporine at the dose of 10 mg/kg/day), Group 3 (animals immunosuppressed with thalidomide at the dose of 100 mg/kg/day), Group 4 (animals immunosuppressed with cyclosporine at the dose of 5.0 mg/kg/day), and Group 5 (animals immunosuppressed with cyclosporine at the dose of 5.0 mg/kg/day in combination with thalidomide at the dose of 50 mg/kg/day). The medications were administered through an orogastric catheter starting on the day before the transplant. The hearts were implanted in the abdomen and the graft vessels were anastomosed with abdominal aorta and cava. RESULTS: The combination of thalidomide and cyclosporine showed the lowest histopathological rejection score (p < 0.05). Thalidomide administered alone or in combination with cyclosporine was effective against rejection, increasing the survival (p < 0.01) of animals submitted to heterotopic heart transplantation in an abdominal position. CONCLUSIONS: Thalidomide may be considered as an adjuvant immunosuppressive drug that can be useful in transplantation.