Type: Polyclonal immunoglobulin (from horse or rabbit)
Mechanism of Action:
ATG contains antibodies that target and deplete human T lymphocytes via complement-mediated lysis and opsonization. This reduces T-cell–mediated immune suppression of hematopoiesis in bone marrow failure syndromes such as MDS and aplastic anemia.
Key Role in MDS:
- Used in immunosuppressive therapy for low-risk or hypoplastic MDS when there is evidence of immune-mediated marrow suppression.
- Most effective in patients with:
- Hypocellular marrow
- Younger age (<60 years)
- Short transfusion history
- HLA-DR15 positivity
Adverse Effects:
- Infusion reactions (fever, chills, hypotension)
- Serum sickness (delayed immune response)
- Risk of infections and cytopenias
- Premedication (steroids, antihistamines, antipyretics) is essential
Synonyms
ATG