For a study, researchers assessed the diagnostic accuracy and utility of the QuantiFERON-TB Gold In-Tube, an interferon-gamma release assay (IGRA), as a screening tool for latent tuberculosis infection (LTBI) in pediatric patients with inflammatory bowel disease (IBD) who were receiving anti-tumor necrosis factor (anti-TNF) medications. They aimed to report tuberculosis cases in the pediatric IBD population, TB treatment courses, and results, as well as their impact on IBD therapy. It was a single-center, retrospective cohort analysis of juvenile inflammatory bowel disease patients who had TB screening. The results, features, and outcomes of IGRA testing from 2011 to 2017 were examined.

On 859 patients, a total of 1,754 tests were done. There were 1,634 negative tests, 9 positive tests, and 111 indeterminate tests. Eight of nine positive tests were obtained during a yearly repeat screening while getting IBD therapy. Five patients were treated for latent tuberculosis infection (LTBI), 4 of them being false positives. IBD treatment was discontinued in three individuals, with no detrimental long-term effects. Researchers described one known false-negative in a patient on anti-TNF medication who acquired widespread TB. Indeterminate testing was more common at the time of IBD diagnosis than during therapy (10.3% vs. 5.3%, P< 0.001). All patients retested for inconclusive findings had negative follow-up testing, with 14 patients lost to follow-up. There were no cases of tuberculosis among patients whose tests were inconclusive. 

IGRAs were valuable for screening for LTBI both before and during anti-TNF medication. The results should be utilized in conjunction with a thorough history and examination. Positive and inconclusive findings should be repeated as soon as possible to ensure rapid TB diagnosis and avoid IBD medication pauses.

Reference:journals.lww.com/jpgn/Fulltext/2019/10000/Performance_of_Interferon_Gamma_Release_Assays_for.19.aspx