Antilymphocytic Antibody: Effects in Experimental Animals and Problems in Human Use

SUMMARY

The effects of antilymphocytic serum (ALS) and antilymphocytic globulin (ALG) in animals and in humans are reviewed. Antilymphocytic serum or ALG appear to affect: [1] the initial recognition of antigen by immunologically competent cells; [2] the expression of delayed hypersensitivity in previously sensitized individuals; [3] the induction of secondary responses to antigen (immunological memory); and [4] the production of circulating antibody, presumably by affecting precursors of antibody-forming cells. Antilymphocytic serum or ALG do not affect: plasma cells already producing antibody, the expression of immune reactions mediated by circulating antibody, or inflammation due to nonspecific initiation.

Antilymphocyte globulin has been effective in suppressing delayed skin reactions and prolonging skin-allograft survival in humans. In view of the potential of ALG in prolonging allograft survival in human recipients, further controlled clinical trials and in vitro studies of antihuman lymphocyte sera are warranted. The experimental data now available can give considerable guidance to approach such trials.