ABIM Test 4 — Questions and Answers
Question 1: A 25-year-old woman is referred for evaluation of iron-deficiency anemia unresponsive to oral iron supplementation. She reports loose stools and a 10-pound weight loss. IgA anti-tissue transglutaminase antibody is markedly elevated. What is the gold-standard confirmatory test?
- HLA-DQ2/DQ8 genotyping
- Capsule endoscopy
- Small bowel biopsy via upper endoscopy (Correct answer)
- Trial of gluten-free diet with symptom assessment
Correct answer: Small bowel biopsy via upper endoscopy
Duodenal biopsy showing villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis remains the gold standard for confirming celiac disease.
Question 2: A 78-year-old man with hypertension and prior stroke is started on apixaban for new atrial fibrillation. His creatinine is 1.8 mg/dL. What is the correct dose of apixaban?
- 2.5 mg twice daily (Correct answer)
- 5 mg twice daily
- 10 mg twice daily
- 20 mg once daily
Correct answer: 2.5 mg twice daily
Dose reduction to 2.5 mg twice daily is required when at least 2 of 3 criteria are met: age ≥80, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL; this patient meets age and creatinine criteria.
Question 3: A 52-year-old man presents with progressive dyspnea and bilateral lower extremity edema. Echo shows EF of 65% with E/e' ratio of 16 and left atrial enlargement. NT-proBNP is 1,200 pg/mL. What is the most likely diagnosis?
- Hypertrophic cardiomyopathy
- Cardiac tamponade
- Heart failure with preserved ejection fraction (HFpEF) (Correct answer)
- Restrictive cardiomyopathy
Correct answer: Heart failure with preserved ejection fraction (HFpEF)
Preserved EF with elevated filling pressures (elevated E/e' ratio), elevated natriuretic peptides, and left atrial enlargement in a symptomatic patient defines HFpEF.
Question 4: A 40-year-old HIV-positive man (CD4 count 80 cells/µL, viral load detectable) develops confusion, fever, and nuchal rigidity. CSF shows elevated opening pressure, 20 WBC/µL (mostly lymphocytes), low glucose, and India ink stain is positive. What is the treatment of choice?
- Fluconazole 400 mg daily
- Amphotericin B deoxycholate plus flucytosine for 2 weeks (Correct answer)
- Voriconazole plus micafungin
- Liposomal amphotericin B monotherapy
Correct answer: Amphotericin B deoxycholate plus flucytosine for 2 weeks
IDSA guidelines recommend amphotericin B deoxycholate plus flucytosine for 2 weeks as induction therapy for cryptococcal meningitis in HIV-infected patients.
Question 5: A 67-year-old woman with a 40 pack-year smoking history has a 6-cm abdominal aortic aneurysm discovered incidentally on ultrasound. She is asymptomatic with no hemodynamic instability. What is the most appropriate management?
- Urgent surgical repair
- Repeat ultrasound in 6 months
- Endovascular aortic repair (EVAR) electively (Correct answer)
- Medical management with beta-blockers only
Correct answer: Endovascular aortic repair (EVAR) electively
AAAs ≥5.5 cm in women (and ≥5.5 cm in men) require repair; EVAR is the preferred approach when anatomy is suitable, performed electively in stable patients.
Question 6: A 33-year-old woman at 10 weeks gestation develops palpitations, tremor, and heat intolerance. TSH is undetectable and free T4 is elevated. She is diagnosed with Graves' disease. Which treatment is preferred in the first trimester?
- Methimazole
- Propylthiouracil (PTU) (Correct answer)
- Radioactive iodine ablation
- Total thyroidectomy
Correct answer: Propylthiouracil (PTU)
PTU is preferred in the first trimester because methimazole is associated with teratogenic effects (aplasia cutis, choanal atresia) during organogenesis.
Question 7: A 59-year-old man presents with progressive symmetric distal lower extremity weakness, hyporeflexia, and a stocking-glove pattern of sensory loss. He was treated for lymphoma 6 months ago. Nerve conduction studies show axonal sensorimotor neuropathy. What is the most likely cause?
- Paraneoplastic neuropathy
- Cisplatin-induced neuropathy
- Vincristine-induced neuropathy (Correct answer)
- Guillain-Barré syndrome
Correct answer: Vincristine-induced neuropathy
Vincristine causes a length-dependent axonal sensorimotor polyneuropathy that typically manifests during or after chemotherapy for lymphoma.
ABIM Test 4
A 25-year-old woman is referred for evaluation of iron-deficiency anemia unresponsive to oral iron supplementation.
She reports loose stools and a 10-pound weight loss.
IgA anti-tissue transglutaminase antibody is markedly elevated.
What is the gold-standard confirmatory test?