CCTN Post-Transplant Immunosuppressive Medications 1 — Questions and Answers
Question 1: Tacrolimus exerts its immunosuppressive effect by inhibiting which enzyme?
- mTOR
- Calcineurin (Correct answer)
- Inosine monophosphate dehydrogenase
- Janus kinase
Correct answer: Calcineurin
Tacrolimus inhibits calcineurin, preventing IL-2 transcription and thereby blocking T-cell activation and proliferation.
Question 2: Which side effect is most associated with long-term tacrolimus use in transplant recipients?
- Hypertension and nephrotoxicity (Correct answer)
- Gingival hyperplasia
- Peripheral neuropathy
- Hepatotoxicity
Correct answer: Hypertension and nephrotoxicity
Long-term tacrolimus use commonly causes nephrotoxicity and hypertension, both of which require ongoing monitoring in transplant recipients.
Question 3: Mycophenolate mofetil (MMF) inhibits which enzyme to suppress lymphocyte proliferation?
- Calcineurin
- mTOR
- Inosine monophosphate dehydrogenase (IMPDH) (Correct answer)
- Dihydrofolate reductase
Correct answer: Inosine monophosphate dehydrogenase (IMPDH)
MMF inhibits IMPDH, blocking de novo purine synthesis which lymphocytes rely on exclusively for proliferation, making it lymphocyte-selective.
Question 4: A transplant nurse notes a tacrolimus trough level of 22 ng/mL in a 3-month post-kidney-transplant patient. What is the most appropriate action?
- Increase the dose because levels should be higher at 3 months
- Notify the provider because the level is supratherapeutic (Correct answer)
- Document and continue current regimen
- Administer a supplemental dose immediately
Correct answer: Notify the provider because the level is supratherapeutic
At 3 months post-transplant, tacrolimus trough targets are typically 8–12 ng/mL; a level of 22 ng/mL is supratherapeutic and requires physician notification.
Question 5: Which immunosuppressant is an mTOR inhibitor used in transplantation?
- Cyclosporine
- Sirolimus (Correct answer)
- Azathioprine
- Basiliximab
Correct answer: Sirolimus
Sirolimus (rapamycin) is an mTOR inhibitor that blocks the intracellular signaling pathway required for T-cell proliferation after IL-2 stimulation.
Question 6: Which medication is used as induction therapy in transplantation and works by depleting T lymphocytes?
- Mycophenolate mofetil
- Tacrolimus
- Anti-thymocyte globulin (ATG) (Correct answer)
- Prednisone
Correct answer: Anti-thymocyte globulin (ATG)
Anti-thymocyte globulin (ATG) is a polyclonal antibody used for induction that rapidly depletes T lymphocytes, reducing the risk of early acute rejection.
CCTN Post-Transplant Immunosuppressive Medications 1
Tacrolimus exerts its immunosuppressive effect by inhibiting which enzyme?