Transplant Surgery Practice Questions

Q: After the first postoperative year of cardiac transplantation, what is the most common cause of death?

Accelerated graft arteriosclerosis. **Explanation:** The survival of cardiac transplant recipients is divided into two distinct phases: the early postoperative period (within the first year) and the late postoperative period (after one year). **Why 'Accelerated Graft Arteriosclerosis' is correct:** Also known as **Cardiac Allograft Vasculopathy (CAV)**, this is a unique, progressive form of chronic rejection. Unlike typical atherosclerosis, CAV is characterized by diffuse, concentric intimal proliferation affecting the entire length of the coronary arteries. It remains the leading cause of late mortality (after 1 year) because the denervated heart does not experience typical angina, often leading to silent myocardial infarction, heart failure, or sudden death. **Why the other options are incorrect:** * **Infection:** This is the **most common cause of death within the first year** (specifically the first 30 days to 6 months) due to intense induction immunosuppression. * **Acute Rejection:** This typically occurs within the first 3–6 months. While it remains a risk, its incidence decreases significantly after the first year due to maintenance therapy. * **Arrhythmia:** While arrhythmias can occur due to surgical trauma or acute rejection in the early phase, they are rarely the primary cause of late-term mortality unless secondary to CAV. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common cause of death ( 1 year):** Cardiac Allograft Vasculopathy (CAV) / Graft Arteriosclerosis. 3. **Gold Standard for CAV diagnosis:** Annual coronary angiography with **Intravascular Ultrasound (IVUS)**, as angiography alone may underestimate the diffuse narrowing. 4. **Malignancy:** The risk of lymphomas (PTLD) and skin cancers increases significantly in the late phase due to long-term immunosuppression.

Q: Which of the following should be avoided in the long-term follow-up of a renal transplant recipient on ciclosporin?

All of the above. In renal transplant recipients on long-term immunosuppression with Ciclosporin, management focuses on preventing graft rejection, avoiding nephrotoxicity, and managing drug-drug interactions. **Explanation of Options:** * **A. Live Vaccines:** Immunosuppressed patients (on Ciclosporin, Tacrolimus, or Mycophenolate) have a diminished immune response. Administering live-attenuated vaccines (e.g., BCG, MMR, Yellow Fever) carries a significant risk of causing disseminated infection from the vaccine strain itself. * **B. Cytochrome P450 (CYP3A4) Inhibitors:** Ciclosporin is extensively metabolized by the hepatic CYP3A4 enzyme system. Drugs that inhibit this system (e.g., Erythromycin, Ketoconazole, Diltiazem) decrease Ciclosporin metabolism, leading to toxic blood levels. Conversely, CYP inducers (e.g., Rifampicin, Phenytoin) lower levels, risking graft rejection. * **C. NSAIDs:** Ciclosporin causes vasoconstriction of the afferent arterioles, reducing renal blood flow. NSAIDs inhibit prostaglandins, which are necessary to maintain afferent arteriolar vasodilation. Combining the two leads to synergistic pre-renal vasoconstriction and acute-on-chronic nephrotoxicity. **Clinical Pearls for NEET-PG:** * **Gingival Hyperplasia:** A classic side effect of Ciclosporin (also seen with Phenytoin and Nifedipine). * **Monitoring:** Therapeutic Drug Monitoring (TDM) is essential for Ciclosporin due to its narrow therapeutic index. * **Metabolic Profile:** Ciclosporin is associated with "H" side effects: **H**ypertension, **H**yperlipidemia, **H**yperglycemia, **H**irsutism, and **H**yperkalemia. * **Tacrolimus vs. Ciclosporin:** Tacrolimus is more potent and lacks hirsutism/gingival hyperplasia but has a higher incidence of New-Onset Diabetes After Transplantation (NODAT).

Q: What type of graft is a graft from a sister to a brother?

Allograft. ### Explanation The correct answer is **Allograft (Option B)**. **1. Why Allograft is correct:** An **allograft** (or homograft) is a transplant between two genetically non-identical members of the same species. Since a brother and sister share approximately 50% of their genetic material (unless they are monozygotic twins), they are genetically distinct individuals. Therefore, any organ or tissue transfer between them is classified as an allograft. This requires immunosuppression to prevent T-cell mediated rejection. **2. Why other options are incorrect:** * **Isograft (Option A):** This is a graft between genetically identical individuals. In humans, this only occurs between **monozygotic (identical) twins**. Since the question specifies a brother and sister (who are dizygotic/siblings), they cannot be genetically identical. * **Autograft (Option C):** This involves a graft taken from one part of a patient's body and transferred to another part of the **same individual** (e.g., a skin graft from the thigh to the arm or a CABG using the radial artery). There is no risk of rejection. * **Heterograft (Option D):** Also known as a **Xenograft**, this is a transplant between members of **different species** (e.g., a porcine/pig heart valve transplanted into a human). **3. Clinical Pearls for NEET-PG:** * **Hyperacute Rejection:** Occurs within minutes to hours due to pre-formed antibodies (Type II Hypersensitivity). * **Acute Rejection:** Occurs within days to weeks; primarily T-cell mediated (Type IV Hypersensitivity). * **Chronic Rejection:** Occurs months to years later; characterized by fibrosis and vascular occlusion. * **Order of Immunogenicity:** Xenograft > Allograft > Isograft = Autograft. * **Graft-versus-Host Disease (GVHD):** Most common in bone marrow transplants where donor T-cells attack the recipient's tissues.

Question 1

After the first postoperative year of cardiac transplantation, what is the most common cause of death?

Accepted Answer

Accelerated graft arteriosclerosis

Answer

Infection

Answer

Arrhythmia

Answer

Acute rejection episode

Question 2

Infection in a renal transplant patient is usually caused by which pathogen?

Accepted Answer

Cytomegalovirus (CMV)

Answer

Human Immunodeficiency Virus (HIV)

Answer

Herpes Simplex Virus (HSV)

Answer

Salmonella

Question 3

Which of the following should be avoided in the long-term follow-up of a renal transplant recipient on ciclosporin?

Accepted Answer

All of the above

Answer

Administer live vaccines

Answer

Prescribe drugs that inhibit cytochrome P450 activity

Answer

Prescribe NSAIDs

Question 4

What type of graft is a graft from a sister to a brother?

Accepted Answer

Allograft

Answer

Isograft

Answer

Autograft

Answer

Heterograft

Question 5

Compared to early immunosuppressive drugs such as azathioprine, steroids, and anti-lymphocyte serum, what specific advantages do newer immunosuppressive agents offer?

Accepted Answer

Tacrolimus (FK506) shares properties with cyclosporine but is particularly useful for rescuing grafts failing under cyclosporine therapy.

Answer

Cyclosporine interferes with lymphokine production and has neither bone marrow nor renal toxicity.

Answer

Monoclonal antibody (OKT3) is more available, more specific, and has fewer side effects than anti-lymphocyte serum.

Answer

None of the above.

Transplant Surgery — MCQs

Transplant Surgery — MCQs

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