An updated systematic review on the applied TST and IGRA Test for diagnosing LTBI in patients treated with TNF-α inhibitor drugs

Abstract

Present systematic review was designed to compare the efficacy of interferon-γ release assays (IGRAs) and tuberculin skin test (TST) for diagnosing latent tuberculosis infection (LTBI) in patients subjected to the anti-TNF-α therapy. The MEDLINE (Ovid), PubMed, Embase, Scopus, Cochrane library, and Web of Science ISI databases were searched for selecting studies to compare the efficiency of IGRAs [QuantiFERONTB Gold (QFT-GT), QuantiFERON-TB Gold In-Tube (QFT-GIT)and T-SPOT.TB] and TST in patients under the anti-TNF-α therapy. After evaluating all studies, we systemically reviewed the results of 37 studies with a total sample size of 8584 patients. The agreement between IGRASs and TST was poor to moderate, however, the anti-TNF-α therapy mostly decreased the percentage of this agreement. BCG vaccination could cause false results of TST assay. The developed active TB in patients with IGRAs positive results during follow-up showed lower than TST positive patients. In conclusion, in the treated patients with anti-TNF-α with previous BCG vaccination, IGRAs might be the better assay to diagnosis LTBI by reducing the false results rate in comparison with the TST. However, more investigations should be done to compare the advantage of IGRAs with conventional test in the treated patients with TNF-α antagonists.