Anti-thymocyte globulin

Anti-thymocyte globulin (ATG) is an infusion of rabbit-derived antibodies against human T cells which is used in the prevention and treatment of acute rejection in organ transplantation and therapy of aplastic anemia.

In the United States it is frequently given at the time of the transplant to prevent rejection, although many European centres prefer to reserve its use for the treatment of steroid-resistant acute rejection, as European centres generally serve more homogeneous populations and rejection tends to be less of a problem.

ATG is associated with cytokine release syndrome when it is used, and in the longer term may increase the risk of post-transplant lymphoproliferative disorder as well as (theoretically) impairing the development of immunological tolerance. Temporary depletion of the T cell population at the time of the transplant also risks delayed acute rejection, which may be missed and cause severe damage to the graft.

Anti-IL-2R&alpha; receptor antibodies such as basiliximab and daclizumab are increasingly being used in place of ATG as an induction therapy, as they do not cause cytokine release syndrome and (theoretically) improving the development of tolerance.

Frequently associated with high grade fevers over 39C, chills, and possibly rigors during administration. These can often be reduced by slowing the infusion rate.