CCTN Transplant Immunology and Rejection 1 — Questions and Answers
Question 1: Which type of rejection occurs within minutes to hours after transplantation and is caused by preformed antibodies?
- Hyperacute rejection (Correct answer)
- Acute cellular rejection
- Chronic rejection
- Accelerated acute rejection
Correct answer: Hyperacute rejection
Hyperacute rejection occurs within minutes to hours due to preformed recipient antibodies against donor antigens, causing immediate graft failure.
Question 2: What is the primary role of HLA matching in solid organ transplantation?
- To determine organ size compatibility
- To reduce the risk of immunologic rejection (Correct answer)
- To match blood types between donor and recipient
- To assess organ function prior to transplant
Correct answer: To reduce the risk of immunologic rejection
HLA matching reduces the immunologic mismatch between donor and recipient, thereby lowering the risk of rejection.
Question 3: Acute cellular rejection is primarily mediated by which immune cells?
- B lymphocytes
- Natural killer cells
- T lymphocytes (Correct answer)
- Neutrophils
Correct answer: T lymphocytes
Acute cellular rejection is primarily mediated by T lymphocytes that recognize donor antigens and mount an immune response against the graft.
Question 4: Which immunologic test is performed before transplantation to detect preformed donor-specific antibodies?
- Complement fixation test
- Cross-match test (Correct answer)
- Western blot
- ELISA for ANA
Correct answer: Cross-match test
The cross-match test mixes recipient serum with donor lymphocytes to detect preformed donor-specific antibodies that could cause rejection.
Question 5: Chronic allograft nephropathy is characterized by which pathological finding on biopsy?
- Neutrophilic infiltration
- Interstitial fibrosis and tubular atrophy (Correct answer)
- Hyperacute vascular thrombosis
- Granulomatous inflammation
Correct answer: Interstitial fibrosis and tubular atrophy
Chronic allograft nephropathy is characterized by interstitial fibrosis and tubular atrophy, reflecting cumulative immune and non-immune injury over time.
Question 6: Panel Reactive Antibody (PRA) levels above what percentage indicate a highly sensitized transplant candidate?
- 20%
- 50%
- 80% (Correct answer)
- 10%
Correct answer: 80%
A PRA of 80% or higher indicates a highly sensitized patient with many preformed antibodies, making it difficult to find a compatible donor.
CCTN Transplant Immunology and Rejection 1
Which type of rejection occurs within minutes to hours after transplantation and is caused by preformed antibodies?