Understanding Human Leukocyte Antigens in Vascularized Composite Allotransplantation

Vascularized composite allotransplantation (VCA) has all the immunogenic risks of solid organ transplantation, while including the complexity and immunogenicity of the skin. This review provides an overview of the human leukocyte antigens (HLAs) system and its current role in VCA. HLA are cell surface glycoproteins critical for immune system surveillance. Their physiological function is to present self-recognized and foreign peptides to inhibit or initiate an immune response through induction, regulation of immune responses, and the selection of T-cells. The HLA system provides targets for stimulation during graft versus host disease, donor-specific HLA antibodies, and allograft rejection. HLA matching, identifying and using acceptable mismatches, and desensitization strategies may increase the immunologic compatibility of the HLA system between a donor and recipient in VCA.