T cells and Rejection in Vascularized Composite Allotransplants

Immune rejection is a major barrier to wider implementation of vascular composite allografts (VCAs) that hold great promise for restoring function in American service members, who have suffered devastating traumatic injuries. Despite systemic immunosuppression, T cell mediated rejection (TCMR) occurs much more frequently in VCA than in solid organ transplants, likely due to the significant number of T donor T cells that survive in the allografts. This study will used banked tissues from VCA patients to comprehensively analyze the contributions of donor versus recipient T cells in VCA rejection. Another question that will be addressed is whether sentinel flaps, transplanted concomitantly with the allograft from the same donor to a distant anatomical site, or circulating levels of clonally expanded T cells, are useful as reliable markers for VCA rejection. IRB approval for this project has been obtained and HRPO approval is pending.