Synergistic effects of ATS and passive and active enhancement on heart and skin allografts in rats.

The effect of a combination of specific and non-specific immunosuppression on survival of heart and skin allografts in parental strain rats differing across the major histocompatibility locus was investigated. Pretreatment of the recipient with donor specific antigen and anti-donor alloantiserum prolonged the survival of heart grafts but not skin grafts. The use of antilymphocyte serum prolonged skin graft survival but not heart graft survival. However, when ATS was combined with donor specific immunosuppression, both heart and skin graft survival were prolonged dramatically. It is suggested that these treatment modalities affect differentially various aspects of the immune responses.