Impact of Donor Bone Marrow on Survival of Composite Tissue Allografts

Composite tissue allotransplants (CTA) involves transplantation of various tissues including vessels, nerves, skin, and immune cells and bears significant antigenic load. Different immunosuppressive protocols are used for experimental and clinical CTA. Immunosuppressive agents maintain survival of the different components of composite tissue allografts. However, the potential side effects of chronic immunosuppression currently limit the widespread application of CTA transplants. Bone marrow therapy in many tolerance induction protocols therefore provides a guide to reaching the target of permanent immunotolerance. Multiple studies suggest that bone marrow is immunomodulatory and may facilitate allograft acceptance. In this review, bone marrow-based therapy protocols of experimental and clinical models are presented in composite tissue transplantation.