A comparative study on the local inflammatory and immunosuppressive activities of anti-mouse anti-lymphocyte sera.

Local inflammatory reaction at the site of injection of anti-human antilymphocyte serum is a troublesome side effect. In this paper, a simple experimental model is presented for studying the local reaction caused by antilymphocyte serum. Anti-mouse antilymphocyte sera were injected intracutaneously and the intensity of the consequent oedema was estimated by the extravasation of Evans Blue dye solution given intravenously. It was found: (a) that rabbit anti-mouse anti-spleen sera produce consistently stronger local reactions than either anti-lymph node or anti-thymus sera; (b) that there is as yet no correlation between the intensity of the local reaction and the immunosuppressive (graft-protective) activity of the anti-lymphocyte serum pools tested. The possible implications of these findings are also discussed.