Kidney transplantation — MCQs

10 questions

A 62-year-old female with a history of uncontrolled hypertension undergoes kidney transplantation. One month following surgery she has elevated serum blood urea nitrogen and creatinine and the patient complains of fever and arthralgia. Her medications include tacrolimus and prednisone. If the patient were experiencing acute, cell-mediated rejection, which of the following would you most expect to see upon biopsy of the transplanted kidney?

Twelve days after undergoing a cadaveric renal transplant for adult polycystic kidney disease, a 23-year-old man has pain in the right lower abdomen and generalized fatigue. During the past 4 days, he has had decreasing urinary output. Creatinine concentration was 2.3 mg/dL on the second postoperative day. Current medications include prednisone, cyclosporine, azathioprine, and enalapril. His temperature is 38°C (100.4°F), pulse is 103/min, and blood pressure is 168/98 mm Hg. Examination reveals tenderness to palpation on the graft site. Creatinine concentration is 4.3 mg/dL. A biopsy of the transplanted kidney shows tubulitis. C4d staining is negative. Which of the following is the most likely cause of this patient's findings?

A 28-year-old woman comes to the physician for a follow-up examination. Two months ago, she underwent left renal transplantation for recurrent glomerulonephritis. At the time of discharge, her creatinine was 0.9 mg/dL. She feels well. Current medications include tacrolimus and azathioprine. Her pulse is 85/min and blood pressure is 135/75 mmHg. Physical examination shows a well-healed surgical scar on her left lower abdomen. The remainder of the examination shows no abnormalities. The patient should be monitored for which of the following adverse effects of her medications?

A 46-year-old man comes to the physician because of a 4-month history of progressively worsening fatigue and loss of appetite. Five years ago, he received a kidney transplant from a living family member. Current medications include sirolimus and mycophenolate. His blood pressure is 150/95 mm Hg. Laboratory studies show normocytic, normochromic anemia and a serum creatinine concentration of 3.1 mg/dL; his vital signs and laboratory studies were normal 6 months ago. Which of the following is the most likely underlying mechanism of this patient’s increase in creatinine concentration?

Several weeks following a kidney transplantation, a 50-year-old Caucasian female presents for evaluation of the transplanted organ. Biopsy shows inflammation involving the endothelial cells of the kidney vasculature and the presence of mononuclear cells in the interstitium. Which cells are most likely responsible for this presentation?

A 14-year-old boy has undergone kidney transplantation due to stage V chronic kidney disease. A pre-transplantation serologic assessment showed that he is negative for past or present HIV infection, viral hepatitis, EBV, and CMV infection. He has a known allergy for macrolides. The patient has no complaints 1 day after transplantation. His vital signs include: blood pressure 120/70 mm Hg, heart rate 89/min, respiratory rate 17/min, and temperature 37.0°C (98.6°F). On physical examination, the patient appears to be pale, his lungs are clear on auscultation, heart sounds are normal, and his abdomen is non-tender on palpation. His creatinine is 0.65 mg/dL (57.5 µmol/L), GFR is 71.3 mL/min/1.73 m2, and urine output is 0.9 mL/kg/h. Which of the following drugs should be used in the immunosuppressive regimen in this patient?

A 58-year-old man is brought to the emergency department because of confusion, weight loss, and anuria. He has chronic kidney disease, hypertension, and type 2 diabetes mellitus. He was diagnosed with acute lymphoblastic leukemia at the age of 8 years and was treated with an allogeneic stem cell transplantation. He is HIV-positive and has active hepatitis C virus infection. He drinks around 8 cans of beer every week. His current medications include tenofovir, emtricitabine, atazanavir, daclatasvir, sofosbuvir, insulin, amlodipine, and enalapril. He appears lethargic. His temperature is 36°C (96.8°F), pulse is 130/min, respirations are 26/min, and blood pressure is 145/90 mm Hg. Examination shows severe edema in his legs and generalized muscular weakness. Auscultation of the lung shows crepitant rales. Laboratory studies show positive HCV antibody and positive HCV RNA. His HIV viral load is undetectable and his CD4+ T-lymphocyte count is 589/μL. Six months ago, his CD4+ T-lymphocyte count was 618/μL. An ECG of the heart shows arrhythmia with frequent premature ventricular contractions. Arterial blood gas analysis on room air shows: pH 7.23 PCO2 31 mm Hg HCO3- 13 mEq/L Base excess -12 mEq/L The patient states he would like to donate organs or tissues in the case of his death. Which of the following is an absolute contraindication for organ donation in this patient?

A 68-year-old woman comes to the physician for a follow-up examination. Three months ago, she underwent heart transplantation for restrictive cardiomyopathy and was started on transplant rejection prophylaxis. Her pulse is 76/min and blood pressure is 148/82 mm Hg. Physical examination shows enlargement of the gum tissue. There is a well-healed scar on her chest. Serum studies show hyperlipidemia. The physician recommends removing a drug that decreases T cell activation by inhibiting the transcription of interleukin-2 from the patient's treatment regimen and replacing it with a different medication. Which of the following drugs is the most likely cause of the adverse effects seen in this patient?

An 18-year-old man is brought to the emergency department due to the confusion that started earlier in the day. His parents report that the patient had recovered from vomiting and diarrhea 3 days ago without medical intervention. They mention that although nausea and vomiting have resolved, the patient continued to have diffuse abdominal pain and decreased appetite. Past medical history is unremarkable, except for a recent weight loss and increased thirst. The patient does not use tobacco products or alcohol. He is not sexually active and does not use illicit drugs. He appears lethargic but responds to questions. His mucous membranes appear dry. Temperature is 36.9°C (98.4°F), blood pressure is 105/60 mm Hg, pulse is 110/min, and respiratory rate is 27/min with deep and rapid respiration. There is diffuse abdominal tenderness without guarding, rebound tenderness or rigidity. Which of the following is the next best step in the management of this patient?

Q10

A 33-year-old man presents to the emergency department because of an episode of bloody emesis. He has had increasing dyspnea over the past 2 days. He was diagnosed with peptic ulcer disease last year. He has been on regular hemodialysis for the past 2 years because of end-stage renal disease. He skipped his last dialysis session because of an unexpected business trip. He has no history of liver disease. His supine blood pressure is 110/80 mm Hg and upright is 90/70, pulse is 110/min, respirations are 22/min, and temperature is 36.2°C (97.2°F). The distal extremities are cold to touch, and the outstretched hand shows flapping tremor. A bloody nasogastric lavage is also noted, which eventually clears after saline irrigation. Intravenous isotonic saline and high-dose proton pump inhibitors are initiated, and the patient is admitted into the intensive care unit. Which of the following is the most appropriate next step in the management of this patient?

Kidney transplantation US Medical PG Practice Questions and MCQs

Question 1: A 62-year-old female with a history of uncontrolled hypertension undergoes kidney transplantation. One month following surgery she has elevated serum blood urea nitrogen and creatinine and the patient complains of fever and arthralgia. Her medications include tacrolimus and prednisone. If the patient were experiencing acute, cell-mediated rejection, which of the following would you most expect to see upon biopsy of the transplanted kidney?

A. Granular immunofluorescence around the glomerular basement membrane
B. Lymphocytic infiltrate of the tubules and interstitium (Correct Answer)
C. Crescent formation in Bowman’s space
D. Drug precipitation in the renal tubules
E. Sloughing of proximal tubular epithelial cells

Explanation: ***Lymphocytic infiltrate of the tubules and interstitium*** - **Acute cell-mediated rejection** is primarily characterized by the infiltration of **T lymphocytes** and macrophages into the allograft, leading to inflammation and damage. - This cellular infiltrate is typically observed in the **interstitium and tubules** of the transplanted kidney. *Granular immunofluorescence around the glomerular basement membrane* - This finding is characteristic of **immune complex-mediated glomerulonephritis**, such as post-streptococcal glomerulonephritis, and signifies deposition of immune complexes. - It is not typical of acute cell-mediated rejection, which is driven by T-cells rather than circulating immune complexes. *Crescent formation in Bowman’s space* - **Crescents** in Bowman's space are indicative of rapidly progressive glomerulonephritis (RPGN), a severe form of glomerular inflammation usually associated with conditions like Goodpasture syndrome or ANCA-associated vasculitis. - While crescentic glomerulonephritis can cause acute kidney injury, it is not the primary histological hallmark of acute cell-mediated transplant rejection. *Drug precipitation in the renal tubules* - **Drug precipitation** can occur with certain medications, leading to acute kidney injury (e.g., sulfonamides, methotrexate), but it is a chemical injury, not an immune-mediated rejection process. - The patient's symptoms of fever and arthralgia, along with elevated creatinine, point towards an inflammatory immune response rather than drug toxicity alone. *Sloughing of proximal tubular epithelial cells* - **Sloughing of proximal tubular epithelial cells** is a hallmark of **acute tubular necrosis (ATN)**, often caused by ischemia or nephrotoxic agents. - While ATN can also lead to elevated creatinine, the presence of fever and arthralgia, plus the context of transplantation, makes acute cell-mediated rejection a more likely diagnosis.

Question 2: Twelve days after undergoing a cadaveric renal transplant for adult polycystic kidney disease, a 23-year-old man has pain in the right lower abdomen and generalized fatigue. During the past 4 days, he has had decreasing urinary output. Creatinine concentration was 2.3 mg/dL on the second postoperative day. Current medications include prednisone, cyclosporine, azathioprine, and enalapril. His temperature is 38°C (100.4°F), pulse is 103/min, and blood pressure is 168/98 mm Hg. Examination reveals tenderness to palpation on the graft site. Creatinine concentration is 4.3 mg/dL. A biopsy of the transplanted kidney shows tubulitis. C4d staining is negative. Which of the following is the most likely cause of this patient's findings?

A. Drug-induced nephrotoxicity
B. Allorecognition with T cell activation (Correct Answer)
C. Irreversible fibrosis of the glomerular vessels
D. Donor T cells from the graft
E. Preformed cytotoxic antibodies against class I HLA

Explanation: ***Allorecognition with T cell activation*** - The patient's symptoms (pain at graft site, fatigue, decreasing urinary output, elevated creatinine) 12 days post-transplant, along with **tubulitis on biopsy** and negative **C4d staining**, are indicative of acute cellular rejection, mediated primarily by **T-cell recognition of donor HLA antigens**. - **Hypertension** and **fever** also support acute rejection, and the immunosuppressive regimen may not be fully effective in preventing this T-cell mediated response. *Drug-induced nephrotoxicity* - While cyclosporine and enalapril can cause kidney injury, the **histological finding of tubulitis** is highly specific for acute cellular rejection, not typically seen with drug-induced nephrotoxicity alone. - Drug-induced nephrotoxicity usually presents with a more **gradual rise in creatinine** and may lack the systemic signs like fever or the specific pathological features of rejection. *Irreversible fibrosis of the glomerular vessels* - This description is more consistent with **chronic allograft nephropathy** or long-term damage, which typically develops months to years after transplantation, not within 12 days. - The findings described (pain, fever, tubulitis) point to an acute process, not chronic fibrosis. *Donor T cells from the graft* - This scenario describes **graft-versus-host disease (GVHD)**, which is rare in solid organ transplantation due to the much smaller lymphocyte load compared to bone marrow transplants. - GVHD typically affects the skin, liver, and gut, and while it involves T-cell mediated injury, the primary damage in renal transplant rejection is directed at the transplanted kidney by the recipient's immune system. *Preformed cytotoxic antibodies against class I HLA* - This describes **hyperacute rejection**, which occurs within minutes to hours of transplantation due to pre-existing antibodies in the recipient against donor antigens. - The patient's symptoms developing 12 days post-transplant, along with the biopsy showing tubulitis and negative C4d staining (indicating absence of significant antibody-mediated complement activation), rule out hyperacute rejection.

Question 3: A 28-year-old woman comes to the physician for a follow-up examination. Two months ago, she underwent left renal transplantation for recurrent glomerulonephritis. At the time of discharge, her creatinine was 0.9 mg/dL. She feels well. Current medications include tacrolimus and azathioprine. Her pulse is 85/min and blood pressure is 135/75 mmHg. Physical examination shows a well-healed surgical scar on her left lower abdomen. The remainder of the examination shows no abnormalities. The patient should be monitored for which of the following adverse effects of her medications?

A. Gingival hyperplasia
B. Kidney injury (Correct Answer)
C. Polycythemia
D. Hepatic necrosis
E. Bone marrow suppression

Explanation: ***Kidney injury*** - **Tacrolimus** is a potent calcineurin inhibitor that can cause **nephrotoxicity** (kidney injury) by inducing afferent arteriolar vasoconstriction and direct tubular toxicity. - Close monitoring of **creatinine** and **tacrolimus trough levels** is essential to prevent and detect this adverse effect, especially in renal transplant patients where baseline function must be preserved. - This is the **most critical monitoring parameter** for tacrolimus therapy. *Gingival hyperplasia* - This adverse effect is more commonly associated with **cyclosporine**, another calcineurin inhibitor, rather than tacrolimus. - While both are immunosuppressants used in transplant, tacrolimus has a lower incidence of this cosmetic side effect. *Polycythemia* - Polycythemia is not a typical adverse effect of **tacrolimus** or **azathioprine**. - Renal transplant patients may sometimes experience erythrocytosis due to increased erythropoietin production from the native kidneys or the transplanted kidney, but it's not directly related to these immunosuppressive medications. *Hepatic necrosis* - While **azathioprine** can cause **hepatotoxicity**, it typically manifests as cholestatic injury or dose-dependent hepatitis, rather than acute hepatic necrosis. - Tacrolimus is not primarily associated with hepatic necrosis. *Bone marrow suppression* - **Azathioprine** is an antimetabolite that can cause **myelosuppression** (leukopenia, thrombocytopenia, anemia) by interfering with DNA synthesis. - While this requires regular **CBC monitoring**, in this clinical scenario, **nephrotoxicity from tacrolimus** is the more immediate concern given the recent renal transplant and the need to preserve graft function. - The question emphasizes creatinine monitoring (baseline 0.9 mg/dL mentioned), directing focus toward tacrolimus nephrotoxicity as the primary monitoring concern.

Question 4: A 46-year-old man comes to the physician because of a 4-month history of progressively worsening fatigue and loss of appetite. Five years ago, he received a kidney transplant from a living family member. Current medications include sirolimus and mycophenolate. His blood pressure is 150/95 mm Hg. Laboratory studies show normocytic, normochromic anemia and a serum creatinine concentration of 3.1 mg/dL; his vital signs and laboratory studies were normal 6 months ago. Which of the following is the most likely underlying mechanism of this patient’s increase in creatinine concentration?

A. Drug-induced tubular vacuolization
B. CD8+ T cell-mediated parenchymal cell damage
C. CD4+ T cell-mediated intimal smooth muscle proliferation (Correct Answer)
D. Donor T cell-mediated epithelial cell damage
E. Donor endothelial cell damage by preformed host antibodies

Explanation: ***CD4+ T cell-mediated intimal smooth muscle proliferation*** - The patient's history of a kidney transplant 5 years ago, worsening fatigue, loss of appetite, elevated blood pressure (150/95 mm Hg), and a significant increase in serum creatinine from normal to 3.1 mg/dL, along with normocytic, normochromic anemia, strongly suggests **chronic rejection** of the renal allograft. - **Chronic rejection** in kidney transplantation is primarily mediated by **CD4+ T cells** which induce injury to vessel walls, leading to **intimal smooth muscle proliferation** and progressive obliteration of the vascular lumen, causing chronic ischemia and graft dysfunction. *Drug-induced tubular vacuolization* - **Drug-induced tubular vacuolization** can occur with medications like sirolimus, but it typically presents with **acute kidney injury** and specific biopsy findings, not the progressive, chronic decline seen here. - While sirolimus can cause nephrotoxicity, the clinical picture of hypertension, anemia, and a gradual increase in creatinine over months, years after transplant, is more indicative of chronic rejection rather than a primary direct tubular injury. *CD8+ T cell-mediated parenchymal cell damage* - **CD8+ T cell-mediated parenchymal cell damage** is characteristic of **acute cellular rejection** and typically presents with a more rapid onset of graft dysfunction and specific histological features like tubulitis and interstitial inflammation. - This patient's symptoms have developed progressively over 4 months, which is more consistent with chronic rather than acute processes. *Donor T cell-mediated epithelial cell damage* - **Donor T cell-mediated epithelial cell damage** is associated with **graft-versus-host disease (GVHD)**, which primarily occurs after **hematopoietic stem cell transplantation**, not solid organ transplants like a kidney. - GVHD manifests in organs like the skin, liver, and GI tract, not typically as isolated chronic allograft nephropathy. *Donor endothelial cell damage by preformed host antibodies* - **Donor endothelial cell damage by preformed host antibodies** is the mechanism of **hyperacute rejection**, which occurs within minutes to hours post-transplant due to pre-existing host antibodies (e.g., ABO incompatible, preformed anti-HLA antibodies) and leads to immediate graft failure. - The patient had a successful transplant 5 years ago and developed symptoms gradually, ruling out hyperacute rejection.

Question 5: Several weeks following a kidney transplantation, a 50-year-old Caucasian female presents for evaluation of the transplanted organ. Biopsy shows inflammation involving the endothelial cells of the kidney vasculature and the presence of mononuclear cells in the interstitium. Which cells are most likely responsible for this presentation?

A. Recipient T-cells (Correct Answer)
B. Donor antibodies
C. Preformed recipient antibodies
D. Deposition of antibody immune complexes
E. Donor T-cells

Explanation: ***Recipient T-cells*** - The presence of **mononuclear cells in the interstitium** and inflammation of the **endothelial cells** several weeks post-transplantation is characteristic of **acute cellular rejection (ACR)**. - ACR is primarily mediated by the recipient's **cytotoxic T-cells** recognizing donor major histocompatibility complex (MHC) molecules on graft cells. *Donor antibodies* - Donor antibodies are not responsible for rejection; rather, recipient antibodies (either preformed or newly formed) are implicated. - The donor's immune system is suppressed or non-existent in the context of the transplanted organ itself after removal from the donor. *Preformed recipient antibodies* - While preformed recipient antibodies cause **hyperacute rejection**, which occurs minutes to hours after transplant, the presentation here is several weeks later. - Hyperacute rejection involves widespread thrombosis and necrosis due to rapid antibody-mediated complement activation within the graft vasculature. *Deposition of antibody immune complexes* - Immune complex deposition typically causes a different pattern of injury (e.g., glomerulonephritis) and is not the primary mechanism of acute cellular rejection. - This mechanism is more associated with certain autoimmune diseases or chronic transplant rejection, not the acute phase described. *Donor T-cells* - Donor T-cells would not be attacking the transplanted organ since it is *their own tissue*. - Donor T-cells can cause **graft-versus-host disease (GVHD)** in bone marrow transplantation, where immunocompetent donor T-cells attack recipient tissues, but this is not applicable to solid organ transplantation.

Question 6: A 14-year-old boy has undergone kidney transplantation due to stage V chronic kidney disease. A pre-transplantation serologic assessment showed that he is negative for past or present HIV infection, viral hepatitis, EBV, and CMV infection. He has a known allergy for macrolides. The patient has no complaints 1 day after transplantation. His vital signs include: blood pressure 120/70 mm Hg, heart rate 89/min, respiratory rate 17/min, and temperature 37.0°C (98.6°F). On physical examination, the patient appears to be pale, his lungs are clear on auscultation, heart sounds are normal, and his abdomen is non-tender on palpation. His creatinine is 0.65 mg/dL (57.5 µmol/L), GFR is 71.3 mL/min/1.73 m2, and urine output is 0.9 mL/kg/h. Which of the following drugs should be used in the immunosuppressive regimen in this patient?

A. Belatacept
B. Sirolimus
C. Omalizumab
D. Daclizumab
E. Basiliximab (Correct Answer)

Explanation: **Basiliximab** - **Basiliximab** is a **monoclonal antibody** that targets the **IL-2 receptor (CD25)** on activated T cells, preventing their proliferation and inducing immunosuppression. - It is commonly used as **induction therapy** in kidney transplant recipients due to its good safety profile, especially in pediatric patients, without the nephrotoxicity associated with calcineurin inhibitors, minimizing acute rejection risks immediately post-transplant. *Belatacept* - **Belatacept** works by co-stimulation blockade, binding to **CD80 and CD86** on antigen-presenting cells to prevent T-cell activation. - It is typically reserved for patients who cannot tolerate calcineurin inhibitors due to **nephrotoxicity** or require a steroid-sparing regimen, which is not indicated as an immediate need in this patient. *Sirolimus* - **Sirolimus** is an **mTOR inhibitor** that works by blocking T-cell proliferation and B-cell differentiation. - It is associated with several side effects, including **delayed wound healing**, **thrombocytopenia**, and **hyperlipidemia**, which are undesirable in the immediate post-transplant period, especially in a growing adolescent. *Omalizumab* - **Omalizumab** is an **anti-IgE monoclonal antibody** primarily used for allergic asthma and chronic spontaneous urticaria. - It has no role in **immunosuppression for organ transplantation** as its mechanism of action is unrelated to preventing graft rejection. *Daclizumab* - **Daclizumab** is another **monoclonal antibody** that also targets the **IL-2 receptor (CD25)**, similar to basiliximab. - However, daclizumab has been **withdrawn from the market** due to serious adverse effects including severe liver injury and autoimmune encephalitis, making it unavailable for clinical use in transplantation.

Question 7: A 58-year-old man is brought to the emergency department because of confusion, weight loss, and anuria. He has chronic kidney disease, hypertension, and type 2 diabetes mellitus. He was diagnosed with acute lymphoblastic leukemia at the age of 8 years and was treated with an allogeneic stem cell transplantation. He is HIV-positive and has active hepatitis C virus infection. He drinks around 8 cans of beer every week. His current medications include tenofovir, emtricitabine, atazanavir, daclatasvir, sofosbuvir, insulin, amlodipine, and enalapril. He appears lethargic. His temperature is 36°C (96.8°F), pulse is 130/min, respirations are 26/min, and blood pressure is 145/90 mm Hg. Examination shows severe edema in his legs and generalized muscular weakness. Auscultation of the lung shows crepitant rales. Laboratory studies show positive HCV antibody and positive HCV RNA. His HIV viral load is undetectable and his CD4+ T-lymphocyte count is 589/μL. Six months ago, his CD4+ T-lymphocyte count was 618/μL. An ECG of the heart shows arrhythmia with frequent premature ventricular contractions. Arterial blood gas analysis on room air shows: pH 7.23 PCO2 31 mm Hg HCO3- 13 mEq/L Base excess -12 mEq/L The patient states he would like to donate organs or tissues in the case of his death. Which of the following is an absolute contraindication for organ donation in this patient?

A. HIV infection
B. Childhood leukemia (Correct Answer)
C. Alcoholism
D. No absolute contraindications
E. Acute kidney injury

Explanation: ***Correct: Childhood leukemia*** - **History of hematologic malignancy** (including acute lymphoblastic leukemia) is an **absolute contraindication** for solid organ donation according to UNOS and OPTN guidelines. - Even though this patient was treated 50 years ago with allogeneic stem cell transplantation, the concern for **residual malignant cells** or **transmission to immunosuppressed recipients** makes this an absolute exclusion. - Unlike solid tumors (which may be acceptable after long disease-free intervals), **leukemias and lymphomas carry lifelong exclusion** from organ donation due to their systemic nature and potential for dormant cells. *Incorrect: Acute kidney injury* - **Acute kidney injury (AKI)** is NOT an absolute contraindication for organ donation. - While the kidneys themselves may not be suitable for transplantation, other organs (heart, liver, lungs, corneas) could still be viable. - Each organ is assessed individually for suitability. *Incorrect: HIV infection* - **Well-controlled HIV infection** (undetectable viral load, stable CD4 count >200) is no longer an absolute contraindication. - Under the **HOPE Act (HIV Organ Policy Equity Act)**, organs from HIV-positive donors can be transplanted into HIV-positive recipients. - This patient has excellent viral control (undetectable VL, CD4 589), making HIV not an absolute barrier. *Incorrect: Alcoholism* - **Alcohol use disorder** alone is not an absolute contraindication for organ donation. - The suitability depends on individual organ assessment (e.g., liver function, cardiac health). - This patient drinks 8 beers/week, which is moderate consumption and doesn't preclude donation of undamaged organs. *Incorrect: No absolute contraindications* - This patient **does have an absolute contraindication**: his history of hematologic malignancy (acute lymphoblastic leukemia). - Despite the long time since treatment, hematologic cancers remain absolute exclusions for organ donation.

Question 8: A 68-year-old woman comes to the physician for a follow-up examination. Three months ago, she underwent heart transplantation for restrictive cardiomyopathy and was started on transplant rejection prophylaxis. Her pulse is 76/min and blood pressure is 148/82 mm Hg. Physical examination shows enlargement of the gum tissue. There is a well-healed scar on her chest. Serum studies show hyperlipidemia. The physician recommends removing a drug that decreases T cell activation by inhibiting the transcription of interleukin-2 from the patient's treatment regimen and replacing it with a different medication. Which of the following drugs is the most likely cause of the adverse effects seen in this patient?

A. Mycophenolate mofetil
B. Azathioprine
C. Tacrolimus
D. Cyclosporine (Correct Answer)
E. Prednisolone

Explanation: ***Cyclosporine*** - The patient's symptoms of **gingival hyperplasia**, **hypertension**, and **hyperlipidemia** are classic side effects associated with cyclosporine. - Cyclosporine is a calcineurin inhibitor that **decreases T-cell activation** by inhibiting IL-2 transcription, matching the drug description. *Mycophenolate mofetil* - Mycophenolate mofetil is an **antiproliferative agent** that inhibits purine synthesis, primarily affecting lymphocytes. - Its common side effects are mainly **hematologic** (leukopenia, anemia) and **gastrointestinal** (diarrhea, nausea), not gingival hyperplasia or hypertension. *Azathioprine* - Azathioprine is a **purine analog** that impairs DNA synthesis and inhibits lymphocyte proliferation. - Key side effects include **myelosuppression** (leukopenia, thrombocytopenia) and **hepatotoxicity**, which are not present here. *Tacrolimus* - Tacrolimus is also a **calcineurin inhibitor** that inhibits IL-2 transcription, similar to cyclosporine. - While it can cause **hypertension** and **hyperlipidemia**, it is less commonly associated with **gingival hyperplasia** than cyclosporine. *Prednisolone* - Prednisolone is a **corticosteroid** used for immunosuppression, acting broadly on the immune system. - Common side effects include **hyperglycemia**, **osteoporosis**, and **cataracts**, not specific gingival overgrowth.

Question 9: An 18-year-old man is brought to the emergency department due to the confusion that started earlier in the day. His parents report that the patient had recovered from vomiting and diarrhea 3 days ago without medical intervention. They mention that although nausea and vomiting have resolved, the patient continued to have diffuse abdominal pain and decreased appetite. Past medical history is unremarkable, except for a recent weight loss and increased thirst. The patient does not use tobacco products or alcohol. He is not sexually active and does not use illicit drugs. He appears lethargic but responds to questions. His mucous membranes appear dry. Temperature is 36.9°C (98.4°F), blood pressure is 105/60 mm Hg, pulse is 110/min, and respiratory rate is 27/min with deep and rapid respiration. There is diffuse abdominal tenderness without guarding, rebound tenderness or rigidity. Which of the following is the next best step in the management of this patient?

A. Abdominal ultrasound
B. ECG
C. MRI of the brain
D. Capillary blood glucose measurement (Correct Answer)
E. CT of the abdomen

Explanation: ***Capillary blood glucose measurement*** - The patient's symptoms, including **confusion**, recent **weight loss**, **increased thirst**, **lethargy**, dry mucous membranes, **tachycardia**, and **Kussmaul respirations** (deep and rapid breathing), are highly suggestive of **diabetic ketoacidosis (DKA)**. - A rapid assessment of **blood glucose** is crucial for confirming DKA and initiating prompt treatment. *Abdominal ultrasound* - While the patient has **diffuse abdominal tenderness**, there are no signs pointing specifically to an intra-abdominal pathology requiring immediate imaging. - The patient's systemic symptoms and Kussmaul respirations are more indicative of a metabolic derangement than a localized abdominal issue. *ECG* - An ECG might be performed later to assess for **cardiac abnormalities** in DKA, especially related to **electrolyte disturbances**, but it's not the immediate diagnostic step. - The priority is to confirm and begin treatment for the metabolic crisis. *MRI of the brain* - Given the patient's acute confusion and other systemic symptoms, an MRI of the brain is not the initial investigation. - **Cerebral edema** can be a complication of DKA, but it typically develops later in the course or during treatment, and initial management focuses on correcting the metabolic state. *CT of the abdomen* - Similar to abdominal ultrasound, a CT scan of the abdomen is not the next best step given the clinical picture. - The symptoms are more consistent with a **metabolic emergency** like DKA, which requires immediate biochemical assessment rather than imaging for abdominal pain.

Question 10: A 33-year-old man presents to the emergency department because of an episode of bloody emesis. He has had increasing dyspnea over the past 2 days. He was diagnosed with peptic ulcer disease last year. He has been on regular hemodialysis for the past 2 years because of end-stage renal disease. He skipped his last dialysis session because of an unexpected business trip. He has no history of liver disease. His supine blood pressure is 110/80 mm Hg and upright is 90/70, pulse is 110/min, respirations are 22/min, and temperature is 36.2°C (97.2°F). The distal extremities are cold to touch, and the outstretched hand shows flapping tremor. A bloody nasogastric lavage is also noted, which eventually clears after saline irrigation. Intravenous isotonic saline and high-dose proton pump inhibitors are initiated, and the patient is admitted into the intensive care unit. Which of the following is the most appropriate next step in the management of this patient?

A. Observation in the intensive care unit
B. Double-balloon tamponade
C. Hemodialysis (Correct Answer)
D. Transfusion of packed red blood cells
E. Esophagogastroduodenoscopy

Explanation: ***Hemodialysis*** - The patient has **end-stage renal disease** and missed his last dialysis session, leading to **uremic crisis** with **dyspnea** (fluid overload) and **asterixis** (uremic encephalopathy). - **Uremic platelet dysfunction** also contributes to the GI bleeding, making dialysis essential to correct coagulopathy. - Emergency hemodialysis is the most critical intervention to remove accumulated toxins, correct fluid overload, and improve hemostasis before any invasive procedures. *Observation in the intensive care unit* - While ICU admission is appropriate for monitoring, passive observation without addressing the underlying **uremia** will not resolve the critical issues of **fluid overload**, **uremic encephalopathy**, and **uremic coagulopathy**. - The patient's missed dialysis session and severe symptoms necessitate active intervention, not just observation. *Double-balloon tamponade* - This procedure is reserved for **life-threatening variceal bleeding** that is refractory to endoscopic treatment. - The patient's history of **peptic ulcer disease** (not cirrhosis) and the clearing of bloody lavage with saline irrigation suggest non-variceal bleeding, making tamponade inappropriate. *Transfusion of packed red blood cells* - While the patient shows signs of **orthostatic hypotension** and **tachycardia** suggesting hypovolemia, the GI bleeding has **stabilized** (NG lavage cleared with irrigation). - Transfusion may be needed based on hemoglobin levels, but it does not address the **immediately life-threatening uremic crisis** with encephalopathy and platelet dysfunction. - The most urgent priority is dialysis to stabilize the patient for subsequent procedures. *Esophagogastroduodenoscopy* - EGD is indicated to identify and potentially treat the source of **upper GI bleeding** in a patient with **peptic ulcer disease**. - However, the patient's severe **uremic symptoms**, **encephalopathy**, and **coagulopathy** must be addressed first to safely perform this invasive procedure and optimize outcomes.

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