Usefulness of screening tests for diagnosis of latent tuberculosis infection in children

Background The aim of this study is to provide a basis for the development of appropriate screening strategies and evaluate the indications of the interferon-gamma release assay (IGRA) in Bacillus Calmette-Guérin (BCG)-vaccinated children. Methods Children who were examined with both IGRA (QuantiFERON®-TB Gold Plus) and tuberculin skin test (TST) for tuberculosis infection were included in the study. Underlying medical conditions of the patients were recorded. Cohen's κ was run to determine if there was an agreement between TST and IGRA. Results A total of 220 patients with a mean age of 11.05 ± 4.43 years (2.5-18 years) were analyzed. Ninety-nine patients were immunocompromised and 121 patients were immunocompetent. TSTs and IGRA showed none to the slight agreement in both of the immunocompromised and immunocompetent patients. In the immunocompromised group, 43/99 (43.4%) and the immunocompetent group 35/121 (28.9%) of the tests did not show any correlation. Conclusion In a high-risk setting where the BCG vaccine is mandatory, it may be beneficial to use IGRA primarily in immunocompetent patients. In immunocompromised patients, the use of both the TST and IGRA could increase the efficacy of screening for latent tuberculosis infection.