Anti-Thymocyte Globulin (ATG)

Indications

Acute Lung Transplant Rejection (Acute Cellular Lung Transplant Rejection) (see Acute Lung Transplant Rejection, [[Acute Lung Transplant Rejection]])
Liver Transplant Induction (see Liver Transplant, [[Liver Transplant]])
Renal Transplant Induction/Rejection (see Renal Transplant, [[Renal Transplant]])
Stem Cell Transplant-Related Graft vs Host Disease (see Graft vs Host Disease, [[Graft vs Host Disease]])

Aplastic Anemia
- Paroxysmal Nocturnal Hemoglobinuria (PNH) (see Paroxysmal Nocturnal Hemoglobinuria, [[Paroxysmal Nocturnal Hemoglobinuria]])

Agents
- Rabbit-Derived Ab (rATG, Thymoglobulin from Genzyme)
- Horse-Derived Ab (eATG, Atgam from Pfizer)
Mechanism
- Antibodies Directed Against T and B-Cell Receptors (Including Human Leukocyte Antigens, HLA): antibodies against CD45 (which plays a role in T-cell activaton) may be particularly important for reversing organ rejection and inducing tolerance
  - Complement-Dependent Opsonization -> T and B-lymphocyte depletion
  - Cytokine Release

Leukopenia (see Leukopenia, [[Leukopenia]])
Serum Sickness (see Serum Sickness, [[Serum Sickness]])
- Epidemiology
  - May occur with subsequent exposure
  - More common with ATGAM
Thrombocytopenia (see Thrombocytopenia, [[Thrombocytopenia]])

Cytokine Release Syndrome (see Cytokine Release Syndrome, [[Cytokine Release Syndrome]]): may last several hours

Anaphylaxis (see Anaphylaxis, [[Anaphylaxis]])
Increased Risk of Malignancy
Increased Risk of Infection
- Primary or Reactivation CMV (see Cytomegalovirus, [[Cytomegalovirus]])

Acute lung injury during antithymocyte globulin therapy for aplastic anemia. Can Respir J. 2009 Mar-Apr;16(2):e3-5 [MEDLINE]
Antithymocyte-associated reticulonodular pneumonitis during a conditioning regimen of reduced intensity for genoidentical bone marrow transplantation. April (2) 2001, Volume 27, Number 8, Pages 891-892 [MEDLINE]
Antithymocyte globulin for acute-graft-versus-host-disease prophylaxis in patients undergoing allogeneic hematopoietic cell transplantation: a systematic review. Leukemia. 2012 Apr;26(4):582-8 [MEDLINE]