An experimental model for hyperacute rejection in inbred rat cardiac transplantation: correlation cardiac graft survival time and anti T-cell warm cytotoxic antibody titer.

Using genetically homogeneous inbred ACI and Fischer rats, the author has conducted active immunization with the skin and lymphoid cells from ACI rat to Fischer rat and succeeded in making an experimental model that unfailingly causes hyperacute rejection, which has heretofore been considered to be extremely difficult. Semipermanent survival was gained with syngenetic graft. With allograft, acute rejection of the cardiac graft took place in 8. 1±1. 4 days. On heart transplantation from ACI to Fischer recipients sensitized by skin graft from ACI and two times active immunization with spleen lymphoid cells from ACI, accelerate rejection occurred in 60. 8±32. 7 hr. On transplantation of ACI heart in Fischer recipients subjected to skin graft and five times or more hyperimmunization with spleen lymphoid cells, hyperacute rejection of the cardiac graft occurred in all cases in 2. 2 ± 3. 5 hr. As regards active immunization and anti-T cell warm cytotoxic antibody formation. skin graft followed by :five times active immunization gave a titer of 28· 11 ±1. 5 and the antibody formation reached a plateau. Anti-T cell warm cytotoxic antibody and survival time of the cardiac graft showed the following correlation. log1o(Y) = -0. 054x+2. 113 log10 (y) = -0. 4742x+3. 4778 C = 3. 622 was recognized. (x<3. 622) (x>3. 622) The anti-T cell warm cytotoxic antibodies were found to be decreased with a significant difference (P<O. 01) after hyperacute rejection. 251