CCTC Transplant Immunology and Pharmacology 2

Question 1

Which cytokine is primarily responsible for driving the differentiation of naive CD4+ T cells into Th17 cells?

Accepted Answer

TGF-β combined with IL-6

Answer

IL-2

Answer

IL-4

Answer

IFN-γ

Question 2

A transplant recipient on tacrolimus develops new-onset diabetes mellitus. What is the most likely mechanism?

Accepted Answer

Direct pancreatic beta-cell toxicity reducing insulin secretion

Answer

Increased hepatic gluconeogenesis via calcineurin inhibition

Answer

Autoimmune destruction of islet cells

Answer

Corticosteroid-induced peripheral insulin resistance only

Question 3

What is the mechanism by which belatacept prevents T-cell activation compared to calcineurin inhibitors?

Accepted Answer

It inhibits the CD28-B7 costimulatory pathway

Answer

It blocks IL-2 receptor signaling

Answer

It prevents mTOR-mediated proliferation

Answer

It depletes circulating T lymphocytes

Question 4

Which HLA mismatch is most strongly associated with hyperacute rejection?

Accepted Answer

Preformed donor-specific antibodies against HLA class I

Answer

HLA-A mismatch

Answer

HLA-DR mismatch

Answer

HLA-DQ mismatch in a sensitized recipient

Question 5

A kidney transplant patient on mycophenolate mofetil (MMF) is started on ciprofloxacin. Which pharmacokinetic interaction is most concerning?

Accepted Answer

Ciprofloxacin reduces enterohepatic recirculation of MPA, lowering drug exposure

Answer

Ciprofloxacin increases MMF levels by inhibiting CYP3A4

Answer

Ciprofloxacin competes with MMF for renal tubular secretion

Answer

No clinically significant interaction exists between these drugs

Question 6

Which complement pathway is primarily activated by antibody-mediated rejection?

Accepted Answer

Classical pathway via C1q binding to antigen-antibody complexes

Answer

Alternative pathway via spontaneous C3 hydrolysis

Answer

Lectin pathway via mannose-binding lectin

Answer

Terminal pathway activation independent of upstream cascades

Question 7

What is the primary reason sirolimus (rapamycin) is often avoided in the early post-transplant period for kidney recipients?

Accepted Answer

It impairs wound healing and increases risk of lymphocele formation

Answer

It causes severe calcineurin inhibitor toxicity when combined

Answer

It directly nephrotoxic in the first month

Answer

It dramatically increases rejection rates compared to tacrolimus