The renewal and burst of interest in various aspects of heterologous antilymphocyte serum during the last several years appear to have resulted from the study of Waksman and his co-workers.1 They demonstrated that rabbit antiguinea pig lymph node serum suppressed the delayed skin reactions to dinitrochlorobenzene, diphtheria toxoid, and old tuberculin in sensitized guinea pigs. Induction of experimental allergic encephalomyelitis in guinea pigs injected with bovine white matter or spinal cord mixed with Freund's adjuvant was also suppressed by the antiserum injection. Furthermore, Waksman et al observed prolongation of the survival of skin allografts in guinea pigs treated with the antiserum. Since the antilymph node serum showed no suppressive effect on the immunological reactions mediated by humoral antibodies, such as passive cutaneous anaphylaxis or reversed passive Arthus reaction or nonimmune inflammatory reactions, the immunosuppressive effect of the antiserum was specific for the lymphocytemediated reactions.
Subsequently, similar findings were reported