Anti-thymocyte globulin (ATG) consists of an infusion of horse or rabbit-derived antibodies against human T cells.
It is used in the prevention and treatment of acute rejection in organ transplantation and therapy of aplastic anemia.
Two antithymocyte globulin (ATG) agents available for clinical use in the United States are Thymoglobulin (rabbit ATG, rATG, Genzyme) and Atgam (equine ATG, eATG, Pfizer).
Both are currently licensed for use in the treatment of renal allograft rejection.
Atgam is additionally licensed for use in the treatment of aplastic anemia.
Horse ATG is pref2242ed over rabbit ATG, demonstrating improved survival.
ATG should be used in combination with cyclosporine A to optimize outcomes.
Its administration reduces immune competence in patients with normal immune systems.
rATG in particular causes large reductions in the number of circulating T-lymphocytes, preventing, or at least delaying, the cellular rejection of transplanted organs.
Use of ATG has a concomitant increased risk of infection and malignancy.
It is frequently given at the time of the transplant to prevent graft-versus-host disease,
ATG use can induce cytokine release syndrome.
Thought to increase the risk of post-transplant lymphoproliferative disorder.
The cytokine release syndrome associated with ATG is frequently associated with high grade fevers, and chills.
Steroids, diphenhydramine 25–50 mg, and acetaminophen are usually co-administered with ATG.
Rabbit ATG has been used in two randomized trials to reduce acute Graft versus Host disease in recipients receiving progenitor cell transplants.