Diagnostic criteria and research progress on Banff classification of allograft pathology in composite tissue allotransplantation

Composite tissue allotransplantation (CTA) is a novel transplantation discipline to treat functional tissue or limb defects. Since a majority of CTA grafts were vascularized grafts, it is also known as vascularized composite allotransplantation (VCA). The grafts of CTA/VCA consist of two or more types of allogeneic skin, subcutaneous tissue, bone, muscle, nerve and vessel, etc. Most of CTA/VCA grafts contain skin tissues, which possess the highest antigenicity. Acute rejection after transplantation is the primary obstacle leading to CTA/VCA graft failure and primary graft dysfunction. Hence, histopathological characteristics of skin rejection in CTA/VCA grafts have become the primary hotspot. In this article, pathological features of CTA/VCA rejection, Banff classification in 2007 and related research progress were reviewed, aiming to provide reference for the diagnosis and treatment of rejection and other complications of CTA/VCA.