NCIt definition : A purified, concentrated and sterile solution of horse-derived gamma globulin obtained
by the immunization of horses with human T-lymphocytes, with T-cell depleting and
immunosuppressive activities. Upon administration, horse anti-thymocyte globulin (hATG)
specifically recognizes, modulates and destroys T-lymphocytes. Although the exact
mechanism of action by which hATG causes immunosuppression is not completely understood,
it is likely caused by a combination of T-lymphocyte depletion, reduction in T-cell
activation and modulation of their cytotoxic activities. Administering of hATG prior
to transplantation may reduce the risk of graft-versus-host disease (GvHD).;