Immunology>Adverse Effect Identification Practice Test

A 60-year-old woman with rheumatoid arthritis has been treated with methotrexate 20 mg once weekly for 4 months; she admits she sometimes forgets her folic acid. She presents with increasing fatigue, easy bruising, bleeding gums, and two recent episodes of epistaxis. She also reports a mouth sore and mild dyspnea on exertion. Vitals are stable. Labs: WBC 2.1 K/mm3, Hgb 8.5 g/dL, Plt 45 K/mm3, MCV 104 fL, AST 38 U/L, ALT 42 U/L, creatinine 0.9 mg/dL. Peripheral smear shows macrocytosis without blasts. No hepatosplenomegaly is noted on exam.

A 36-year-old man with severe rheumatoid arthritis started infliximab infusions 6 weeks ago after inadequate response to methotrexate. He reports a 3-week history of nonproductive cough, low-grade fevers, drenching night sweats, and 8-lb weight loss. He recently emigrated from a region with high tuberculosis prevalence and is unsure if he was ever tested for TB before starting biologic therapy. Vitals: T 100.8 F, HR 96, BP 118/72, SpO2 95% on room air. Physical exam reveals mild crackles over the right upper lung field. Chest radiograph shows patchy right apical opacities with cavitation. WBC 7.8, hemoglobin 12.9, platelets 265. AST/ALT are normal. Sputum AFB smears and an interferon-gamma release assay are pending. He asks whether this could be related to his new medication.