Latent TB infection screening for patients preparing to receive a TNF-alpha inhibitor who do not have risk factors for latent TB

TB: tuberculosis; TNF: tumor necrosis factor; IGRA: interferon-gamma release assay; TST: tuberculin skin test; LTBI: latent tuberculosis infection; BCG: Bacille Calmette-Guérin.
* We prefer the IGRA over the TST as it is likely more sensitive under conditions of immunosuppression, it can be accomplished in one visit, and it eliminates the need to know a patient's BCG history (which is not always clear). In patients who have not received the BCG vaccine, the TST is a reasonable alternative to the IGRA.
¶ The two IGRAs are the QuantiFERON-TB Gold In-Tube and the T-SPOT.TB assay. When retesting, it is acceptable to use either the same IGRA or the other assay. In patients who have not received the BCG vaccine, the TST is a reasonable alternative to the IGRA.