Antigenicity of alumina ceramic and calcium phosphate ceramics--genetic control of the immune response

Antigenicity of alumina ceramic, hydroxyapatite ceramic and tricalcium phosphate ceramic was studied by induction of footpad swelling in C57BL/6 mice immunized by ceramics with Freund's complete adjuvant. Significant footpad swelling was observed in mice immunized with tricalcium phosphate ceramic at 2 and 4 weeks after immunization. Antigenic specificity was demonstrated between tricalcium phosphate ceramic and fetal bovine serum in crisscross. Time course of the reaction suggested that delayed-type hypersensitivity played an important role in footpad swelling. These results indicate that tricalcium phosphate ceramic has antigenicity to C57BL/6 mice. Antigenicity of alumina ceramic and hydroxyapatite ceramic was not demonstrated in this study. A positive footpad reaction to tricalcium phosphate ceramic was shown in C57BL/10 (H-2b) and C57BL/10 X BR (H-2k), but was not observed in C57BL/10 X D2(H-2d). These results suggest that this response to tricalcium phosphate ceramic was under control by a gene located within the major histocompatibility complex.