An investigation into the immunogenicity of various components of osteoarticular grafts.

Rats have been grafted subcutaneously with heterografts of sheep osteoarticular tissues. Antibody against sheep transplantation antigens has been sought. The results of the studies indicate that articular cartilage alone is poorly immunogenic and if it does lead to an immune response, this response is delayed; it is the bone components of the composite osteoarticular grafts which are highly immunogenic and in most recipients cause a brisk production of antibodies. It is suggested that the cartilage matrix forms a protective barrier to both the afferent and the efferent arms of the immune response.