Inflammatory Bowel Disease USMLE Step 1 Practice Question
A 45-year-old man with a 10-year history of ulcerative colitis presents with a 3-week exacerbation characterized by bloody diarrhea (8-10 stools/day), crampy abdominal pain, and fever to 38.2°C. His disease has not responded to 8 weeks of high-dose mesalamine and a 6-week course of corticosteroids with attempted taper. Vital signs show HR 92/min, BP 128/82 mmHg, RR 16/min. Laboratory studies reveal hemoglobin 9.8 g/dL, albumin 2.9 g/dL, and CRP 8.2 mg/dL. Serologic testing shows: HBsAg positive, anti-HBc positive, anti-HBs negative, and HBeAg negative. Liver function tests are normal. He denies tuberculosis exposure and has normal chest X-ray. He is otherwise healthy with no prior infections. Before initiating anti-TNF-alpha therapy (infliximab), which of the following is the most important management step?
Answer choices
- AInitiate therapy immediately without further workup; HBsAg positivity with normal transaminases indicates resolved infection
- BObtain baseline HBV DNA level and start prophylactic antiviral therapy (lamivudine or entecavir) before and during TNF inhibitor useCorrect answer
- CAdminister hepatitis B vaccine series prior to TNF inhibitor initiation to confer immunity
- DPerform liver biopsy to assess for cirrhosis before considering any biologic agent
- EDefer all biologic agents and switch to azathioprine monotherapy to avoid viral reactivation risk
- FScreen for hepatitis C antibodies before proceeding; if negative, TNF inhibitors can be safely used
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