Q. A 43-year-old woman visits the outpatient clinic for rheumatoid arthritis follow-up. The patient was diagnosed with rheumatoid arthritis 6 months ago. Despite being consistent with her scheduled methotrexate therapy with no major side effects, she still has had ongoing progressive hand deformities. The attending rheumatologist decides to administer infliximab to help stop the progression of her arthritis. Which of the following should be assessed before administration of infliximab?