Immunological transformations in the recipient of grafted allogeneic human bone

Twenty-one patients received allogeneic human bone grafts following deep freezing according to various orthopaedic indications. The HLA antigens of all donors and recipients had been determined preoperatively, and grafting was performed without any respect to the HLA match. The immunological follow-up of the recipients was managed by two different methods: MLC (mixed lymphocyte culture) and MAILA (monoclonal antibody-specific immobilisation of lymphocyte antigens). No immunosuppression was performed. The follow-up lasted up to 6 years. Allogeneic grafting of human cancellous bone induces specific immunological reactions in the recipient. The consequences of these observations are: (1) allogeneic bone grafting may induce second-set reactions following subsequent blood transfusion, tissue grafting or organ transplantation; (2) transplantation of fresh, perfused, vascularised allogeneic bone or joint may become a therapeutic approach in the near future. Then the employment of standard immunosuppressive protocols will be mandatory in order to fight acute rejection of the graft.