Latent tuberculosis infection screening in patients with inflammatory bowel disease: a nationwide retrospective cohort study in South Korea comparing IGRA alone versus a combination of TST and IGRA

Background/aims We aimed to evaluate if using the interferon-gamma release assay (IGRA) alone is effective for latent tuberculosis infection (LTBI) screening in preventing active tuberculosis in patients with inflammatory bowel disease (IBD) before initiating anti-tumor necrosis factor alpha (anti-TNF-α) therapy, compared to using both the tuberculin skin test and IGRA. Methods Using South Korea's Health Insurance Review and Assessment Service, we selected IBD patients treated with anti-TNF-α agents for ≥ 1 year who underwent LTBI screening between 2018 and 2021. We compared the 1-year incidence rate and standardized incidence ratio of active tuberculosis incidence after starting anti-TNF-α treatment to the general population based on the LTBI screening strategy. Results Of the 4,215 enrolled patients, 3,505 underwent IGRA alone for LTBI screening, while 710 received both tuberculin skin test and IGRA. Within 1 year of starting anti-TNF-α treatment, 15 patients (0.36%) developed active tuberculosis, with a mean follow-up period of 4,200.6 person-years. The 1-year tuberculosis incidence rates were 372.3 (95% confidence interval [CI], 198.2-636.6) per 100,000 person-years for the IGRA alone group and 282.3 (95% CI, 34.2-1,019.9) per 100,000 person-years for the combination group. The standardized incidence ratios were similar: 14.34 (95% CI, 7.63-24.52) for the IGRA alone group and 11.25 (95% CI, 1.26-40.61) for the combination group. Conclusions Using IGRA alone may be an effective strategy for LTBI screening in IBD patients before starting anti-TNF-α therapy. (Intest Res, Published online ).