Immunologic protection of rabbit corneal allografts: preparation and in vitro testing of heterologous "blocking" antibody.

Corneal allografts, like other foreign tissues, are subject to immunologic attack and rejection. Efforts to prolong graft survival have included the use of antilymphocyte serum and blocking antibodies. In this study antilymphocyte serum was tested as a potential corneal allograftblocking reagent. It has been demonstrated that guinea pig anti-rabbit lymphocyte serum and the gamma globulin fraction of this serum bind to rabbit lymphocytes and corneal cells. In the presence of serum complement the antiserum and globidin are cytotoxic for cells of the cornea. Chemical modificaton of the anti-lymphocyte globulin renders it incapable of complement fixation, creating a reagent which retains the capacity to bind to cells and, in addition, to protect them from the cytotoxic effects of unaltered antibody and serum complement. The benign and protective nature of modified antilymphocyte globulin suggests that it is an excellent candidate for use in the prevention of corneal graft rejection.