Immunosuppressants US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Immunosuppressants. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Immunosuppressants US Medical PG Question 1: Two weeks after undergoing allogeneic stem cell transplant for multiple myeloma, a 55-year-old man develops a severely pruritic rash, abdominal cramps, and profuse diarrhea. He appears lethargic. Physical examination shows yellow sclerae. There is a generalized maculopapular rash on his face, trunk, and lower extremities, and desquamation of both soles. His serum alanine aminotransferase is 115 U/L, serum aspartate aminotransferase is 97 U/L, and serum total bilirubin is 2.7 mg/dL. Which of the following is the most likely underlying cause of this patient's condition?
- A. Preformed cytotoxic anti-HLA antibodies
- B. Proliferating transplanted B cells
- C. Activated recipient T cells
- D. Donor T cells in the graft (Correct Answer)
- E. Newly formed anti-HLA antibodies
Immunosuppressants Explanation: ***Donor T cells in the graft***
- The symptoms (rash, GI symptoms, liver dysfunction) after an allogeneic stem cell transplant are classic signs of **acute graft-versus-host disease (GVHD)**. This condition occurs when **immunocompetent T cells from the donor graft** recognize the recipient's tissues as foreign and mount an immune attack.
- The rapid onset within two weeks post-transplant, elevated liver enzymes, jaundice (**yellow sclerae**, **elevated bilirubin**), severe pruritic rash, and GI symptoms (**abdominal cramps**, **profuse diarrhea**) are all characteristic manifestations of acute GVHD.
*Preformed cytotoxic anti-HLA antibodies*
- Preformed antibodies would typically cause **hyperacute rejection**, which occurs within minutes to hours of transplantation and involves widespread thrombosis and necrosis of the graft, not the systemic symptoms seen here.
- This reaction is mediated by the recipient's antibodies attacking donor antigens, leading to immediate graft failure.
*Proliferating transplanted B cells*
- Transplanted B cells can contribute to chronic GVHD through antibody production, but they are not the primary mediators of **acute GVHD**; acute GVHD is predominantly a T cell-mediated process.
- Proliferation of donor B cells is more commonly associated with post-transplant lymphoproliferative disorders (PTLD) or chronic GVHD, not the acute presentation described.
*Activated recipient T cells*
- In an allogeneic transplant, the recipient's immune system is usually heavily suppressed beforehand to prevent host-versus-graft rejection.
- If recipient T cells were active, they would primarily cause **rejection of the donor stem cells** (graft rejection), not the systemic symptoms of GVHD, which is a reaction of the donor cells against the host.
*Newly formed anti-HLA antibodies*
- Newly formed antibodies the recipient develops against the donor's HLA antigens would cause graft rejection, a process often delayed but not presenting as the widespread organ damage of acute GVHD.
- These antibodies are part of the host's attempt to reject the foreign graft, not the donor cells attacking the host.
Immunosuppressants US Medical PG Question 2: A 56-year-old African American presents to the emergency department due to abdominal pain, fatigue, and weight loss over the past 3 months. He has a long-standing history of chronic hepatitis B virus infection complicated by cirrhosis. On examination, he has jaundice, leg edema, and a palpable mass in the right upper abdominal quadrant. Abdominal ultrasound shows a 3-cm liver mass with poorly defined margins and coarse, irregular internal echoes. Blood investigations are shown:
Aspartate aminotransferase (AST) 90 U/L
Alanine aminotransferase (ALT) 50 U/L
Total bilirubin 2 mg/dL
Albumin 3 g/dL
Alkaline phosphatase 100 U/L
Alpha fetoprotein 600 micrograms/L
Which of the following targeted agents is approved for advanced-stage hepatoma?
- A. Ustekinumab
- B. Daclizumab
- C. Sorafenib (Correct Answer)
- D. Abciximab
- E. Palivizumab
Immunosuppressants Explanation: ***Sorafenib***
- This patient's presentation with chronic hepatitis B, cirrhosis, a liver mass, and an **elevated alpha-fetoprotein** is highly suggestive of **hepatocellular carcinoma (HCC)**, also known as hepatoma.
- **Sorafenib** is a **multi-targeted tyrosine kinase inhibitor** that inhibits tumor cell proliferation and angiogenesis by targeting VEGFR, PDGFR, Raf kinases, and other kinases involved in tumor progression.
- It was the **first systemic therapy approved for advanced-stage HCC** and remains an important first-line treatment option for patients with advanced disease who are not candidates for surgical or locoregional therapies.
*Ustekinumab*
- **Ustekinumab** is a monoclonal antibody that targets the **p40 subunit of IL-12 and IL-23**, primarily used in the treatment of **psoriasis** and psoriatic arthritis, not HCC.
- It works by blocking inflammatory pathways involved in autoimmune conditions.
*Daclizumab*
- **Daclizumab** is a humanized monoclonal antibody that targets the **CD25 subunit of the IL-2 receptor**; it was previously used for treating **multiple sclerosis** but has been largely discontinued due to safety concerns.
- It is not indicated for the treatment of any form of cancer.
*Abciximab*
- **Abciximab** is a monoclonal antibody that targets the **glycoprotein IIb/IIIa receptor** on platelets, used as an **antiplatelet agent** in patients undergoing percutaneous coronary intervention.
- Its mechanism of action is related to inhibition of platelet aggregation and thrombosis, not cancer therapy.
*Palivizumab*
- **Palivizumab** is a monoclonal antibody used for the **prevention of serious lower respiratory tract disease** caused by **respiratory syncytial virus (RSV)** in high-risk infants.
- It provides passive immunity against RSV and has no role in cancer treatment.
Immunosuppressants US Medical PG Question 3: A patient with HCC and a long history of alcohol dependence and chronic hepatitis C has been using the mTOR inhibitor sirolimus 100 mg for cancer treatment. Her cancer has shown a partial response. She also has a history of hypertension and poorly controlled type 2 diabetes mellitus complicated by diabetic retinopathy. Current medications include enalapril and insulin. She asks her oncologist and hepatologist if she could try everolimus for its purported survival benefit in treating HCC. Based on clinical considerations, which of the following statements is most accurate?
- A. The patient should start everolimus 50 mg because of the survival benefit relative to sirolimus 100 mg
- B. The patient is not a good candidate for everolimus due to her history of hypertension
- C. The patient should start everolimus 100 mg because of the survival benefit relative to sirolimus 100 mg
- D. The patient should start everolimus 50 mg because of her history of alcohol use disorder and hepatitis C
- E. The patient is not a good candidate for everolimus due to her history of diabetes (Correct Answer)
Immunosuppressants Explanation: ***The patient is not a good candidate for Noxbinle due to her history of diabetes***
- The current medication is sirolimus, an **mTOR inhibitor** and its successor everolimus, also an mTOR inhibitor, is not beneficial for this patient due to her **poorly controlled type 2 diabetes mellitus**.
- mTOR inhibitors, including everolimus, are known to **worsen hyperglycemia** and **accelerate the progression of diabetes**, making it contraindicated in patients with already complicated diabetes.
*The patient should start everolimus 50 mg because of the survival benefit relative to sirolimus 100 mg*
- There is **no established evidence** that everolimus at any dose offers a superior survival benefit compared to sirolimus in HCC, particularly after a partial response to sirolimus.
- **Switching mTOR inhibitors** without a compelling clinical reason, especially with existing comorbidities, is not standard practice.
*The patient is not a good candidate for everolimus due to her history of hypertension*
- While mTOR inhibitors can contribute to **hypertension**, this patient is already on **enalapril** for her existing hypertension.
- Her **poorly controlled diabetes** presents a more direct and severe contraindication due to the metabolic side effects of everolimus.
*The patient should start everolimus 100 mg because of the survival benefit relative to sirolimus 100 mg*
- No clinical data supports a **superior survival benefit** of everolimus 100 mg over sirolimus 100 mg in HCC.
- Given the patient's existing **poorly controlled diabetes**, increasing the dose of an mTOR inhibitor or switching to an equivalent dose of another would heighten the risk of severe metabolic complications.
*The patient should start everolimus 50 mg because of her history of alcohol use disorder and hepatitis C*
- The patient's history of alcohol dependence and chronic hepatitis C are **risk factors for HCC** but do not directly contraindicate a specific dose of everolimus more than her diabetes.
- While liver impairment due to these conditions might influence dosing of various medications, the **primary concern for everolimus** in this case remains the uncontrolled diabetes.
Immunosuppressants US Medical PG Question 4: A 67-year-old man is seen on the surgical floor after a transplant procedure. The previous day, the patient had a renal transplant from a matched donor. He is currently recovering and doing well. The patient has a past medical history of IV drug use, diabetes mellitus, oral cold sores, hypertension, renal failure, and dyslipidemia. The patient's current medications include lisinopril, atorvastatin, insulin, and aspirin. Prior to the procedure, he was also on dialysis. The patient is started on cyclosporine. The patient successfully recovers over the next few days. Which of the following medications should be started in this patient?
- A. Azithromycin
- B. TMP-SMX (Correct Answer)
- C. Acyclovir
- D. Low dose acyclovir
- E. Penicillin
Immunosuppressants Explanation: ***TMP-SMX***
- **TMP-SMX (trimethoprim-sulfamethoxazole)** is the **most critical** prophylactic medication for all solid organ transplant recipients on immunosuppression.
- It provides essential prophylaxis against **Pneumocystis jirovecii pneumonia (PJP)**, a life-threatening opportunistic infection with high mortality if not prevented.
- PJP prophylaxis is a **universal recommendation** for all transplant patients and is typically continued for 6-12 months post-transplant.
- Additionally offers protection against **Toxoplasma gondii**, **Nocardia**, and common urinary tract infections, making it particularly valuable in renal transplant recipients.
*Azithromycin*
- Azithromycin is a macrolide antibiotic used for specific bacterial infections and sometimes for **Mycobacterium avium complex (MAC)** prophylaxis in severely immunocompromised patients.
- It is not standard prophylaxis in routine post-transplant care and does not protect against PJP, the most critical opportunistic infection in this setting.
*Acyclovir*
- High-dose acyclovir is used to **treat active HSV or VZV infections**, not for routine prophylaxis.
- This patient has no active viral infection requiring treatment doses at this time.
*Low dose acyclovir*
- Low-dose acyclovir (or valacyclovir) is indeed used for **HSV/VZV prophylaxis** in transplant patients, especially those with a history of cold sores.
- Many transplant centers do initiate this medication alongside TMP-SMX in the post-transplant period.
- However, in a **single-best-answer** context, **TMP-SMX takes priority** as it prevents PJP, which is universally life-threatening and has higher incidence without prophylaxis compared to severe HSV reactivation.
- TMP-SMX is considered the **essential first-line** prophylaxis that all transplant patients must receive.
*Penicillin*
- Penicillin is a narrow-spectrum antibiotic effective against certain gram-positive bacteria.
- It has no role in post-transplant opportunistic infection prophylaxis and does not protect against PJP, HSV, or other transplant-related infections.
Immunosuppressants US Medical PG Question 5: An epidemiologist is evaluating the efficacy of Noxbinle in preventing HCC deaths at the population level. A clinical trial shows that over 5 years, the mortality rate from HCC was 25% in the control group and 15% in patients treated with Noxbinle 100 mg daily. Based on this data, how many patients need to be treated with Noxbinle 100 mg to prevent, on average, one death from HCC?
- A. 20
- B. 73
- C. 10 (Correct Answer)
- D. 50
- E. 100
Immunosuppressants Explanation: ***10***
- The **number needed to treat (NNT)** is calculated by first finding the **absolute risk reduction (ARR)**.
- **ARR** = Risk in control group - Risk in treatment group = 25% - 15% = **10%** (or 0.10).
- **NNT = 1 / ARR** = 1 / 0.10 = **10 patients**.
- This means that **10 patients must be treated with Noxbinle to prevent one death from HCC** over 5 years.
*20*
- This would result from an ARR of 5% (1/0.05 = 20), which is not supported by the data.
- May arise from miscalculating the risk difference or incorrectly halving the actual ARR.
*73*
- This value does not correspond to any standard calculation of NNT from the given mortality rates.
- May result from confusion with other epidemiological measures or calculation error.
*50*
- This would correspond to an ARR of 2% (1/0.02 = 50), which significantly underestimates the actual risk reduction.
- Could result from incorrectly calculating the difference as a proportion rather than absolute percentage points.
*100*
- This would correspond to an ARR of 1% (1/0.01 = 100), grossly underestimating the treatment benefit.
- May result from confusing ARR with relative risk reduction or other calculation errors.
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