Recommended Dosing of Anti-Thymocyte Globulin (ATG) for T Cell Mediated Rejection
The recommended dose of Anti-Thymocyte Globulin (ATG) for T cell mediated rejection is 0.75-1.5 mg/kg IV daily for 5-7 days. 1
Dosing Guidelines for Rabbit ATG (Thymoglobulin)
Standard Dosing
- Rabbit ATG (thymoglobulin): 0.75-1.5 mg/kg IV daily for 5-7 days 1
- First dose should be administered over at least 6 hours, with subsequent doses potentially given over 4 hours if administered through a central line 2
Premedication Requirements
To minimize infusion-related reactions, the following premedications should be administered:
- Corticosteroids: Methylprednisolone 2 mg/kg IV 4 hours prior to ATG, then 0.5 mg/kg IV every 6 hours until 24 hours after completion of ATG dosing 3
- Antihistamine: Diphenhydramine (Benadryl) 1 mg/kg 2
- Antipyretic: Acetaminophen (Tylenol) 10-15 mg/kg 2
Dosing Considerations for Special Populations
Cardiac Transplant Recipients with Antibody-Mediated Rejection
- For cardiac transplant patients with severe hemodynamic compromise: ATG 1.5 mg/kg daily for 3-7 days, often combined with plasmapheresis 1, 2
- For pediatric heart transplant recipients: 1.5 mg/kg IV daily for 5-7 days 2
Individualized Dosing Approach
Some centers utilize T-cell monitoring to guide ATG dosing:
- Target CD3+ T-cell count below 50 cells/mm³ 4, 5
- This approach has been shown to be as effective as fixed dosing while potentially reducing complications and cost 6
Administration Considerations
Infusion Protocol
- Start at a slow rate (0.125 mL/kg/hr) and gradually increase if tolerated 3
- Administer through a central line when possible
- Monitor vital signs frequently during infusion
Monitoring During Treatment
- Daily complete blood count with differential
- T-cell counts if available
- Renal and hepatic function tests
- Monitor for signs of infection, particularly viral infections
Potential Complications and Management
Common Adverse Effects
- Fever, chills, rigors
- Gastrointestinal symptoms (diarrhea, abdominal pain, nausea, vomiting)
- Myalgias, headache, dizziness
- Hypertension, tachyarrhythmia
Serious Adverse Effects
- Leukopenia, thrombocytopenia
- Increased risk of infections (viral, fungal, bacterial)
- Increased risk of post-transplant lymphoproliferative disorder (PTLD)
- Cytokine release syndrome
Risk Mitigation
- Consider prophylactic antimicrobials during treatment
- Monitor for CMV reactivation
- Adjust concomitant immunosuppression as needed
Treatment Algorithm for T Cell Mediated Rejection
- Confirm diagnosis of T cell mediated rejection via biopsy
- Assess severity and hemodynamic status
- Initiate ATG at 0.75-1.5 mg/kg IV daily
- Administer appropriate premedications
- Monitor T-cell counts daily if available
- Continue for 5-7 days total
- Adjust concomitant immunosuppression as needed
By following these dosing guidelines and monitoring protocols, ATG can be effectively used to treat T cell mediated rejection while minimizing potential complications.