Immunogenicity of Allograft Articular Cartilage

Allograft articular cartilage was transplanted between inbred strains of rats and between rabbits. Three forms of allograft were employed: isolated articular chondrocytes, shavings of articular cartilage, and intact articular surfaces. Immunological assessment with the leukocyte migration technique for cell-mediated immunity and Cr51 cytotoxicity for humoral antibody levels demonstrated that articular chondrocytes possess transplantation antigens and are immunogenic. Moreover, histological evaluation of grafts of shavings of articular cartilage showed round-cell infiltration into the lacunae. If the cartilage matrix was intact, as in intact articular surface grafts, sensitization of hosts did not occur. Sulphur-35 uptake studies revealed that these grafts remain viable even in presensitized recipients, suggesting that humoral antibodies cannot penetrate intact matrix to reach the chondrocytes.