American Board of Internal Medicine (ABIM) Certification Practice Exam

Before initiating any biologic agent, what screening is indicated?

1. HIV screening

2. Chest X-ray

3. Tuberculosis screening

4. Blood glucose levels

The correct answer is: Tuberculosis screening

Before initiating any biologic agent, tuberculosis screening is indicated due to the risk of reactivation of latent tuberculosis infection (LTBI) associated with immunosuppressive therapies. Biologics, which are often used for conditions like rheumatoid arthritis, psoriasis, and inflammatory bowel disease, can significantly dampen the immune response, increasing the likelihood of infections, particularly with mycobacteria. The most commonly used screening method for LTBI is the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). If a patient is found to have active tuberculosis or LTBI, appropriate treatment must be initiated before starting the biologic therapy to reduce the risk of severe infections. While HIV screening, chest X-rays, and blood glucose level checks are important in various contexts, they do not have the same direct relationship to the initiation of biologics as tuberculosis screening does. HIV screening is relevant for immunocompromised patients, a chest X-ray could be useful for diagnosing active TB but is not a standard pre-screening procedure, and blood glucose levels are typically checked in the context of diabetes management rather than as a prerequisite for starting biologics.