Abstract
1. The humoral immune response of rats against sheep iliac bone grafts has been examined.
2. Fresh, marrow-containing grafts elicited a brisk and sustained antibody response. Attempts to wash out the marrow were not uniformly successful in removing cellular antigens from the grafts.
3. Decalcifying and freezing bone grafts at —20 degrees Celsius do not impair immunogenicity to any significant extent. Immunogenicity was found to be reduced in grafts subjected to freeze-drying.
4. Deproteinised Oswestry bone grafts and Kiel grafts gave rise to antibody production in a few recipients, and in the case of the former this response did not occur until after six or seven weeks from grafting.
5. The highest degree of osteogenesis in composite bone xenograft-autografts was found by Salama and colleagues (1973) to occur in Oswestry bone grafts. It is suggested that osteogenesis in xenografts may be impaired by an immune response.