Interferon-γ release assay for the diagnosis of tuberculosis in children.

ABSTRACT

AIMS: To compare the QuantiFERON-TB GOLD In Tube test (QTF) and the tuberculin skin test (TST) in children. METHODS: A prospective study was carried out in nine hospitals in Madrid, Spain. TST and QTF were performed in immigrants, tuberculosis (TB) contacts and patients with TB disease (TBD). RESULTS: 459 children were included. Disagreement between the tests was more frequently observed among latent tuberculosis infection (LTBI) cases (54%; 38/70) than in non-infected or TBD cases (0.8%; 3/369) (p<0.01). There were more BCG-vaccinated children among LTBI cases with negative QTF (76%) than among LTBI cases with positive QTF (40%) (p<0.001). Agreement between tests in BCG-vaccinated children was lower than in non-vaccinated cases (p<0.05). Tests in TB exposed patients showed better agreement than in non-exposed children (p<0.05). CONCLUSIONS: Agreement of both tests was excellent in TBD cases, non-vaccinated children and non-infected patients. A significant number of QTF negative results were observed among LTBI cases, especially in BCG-vaccinated children. Agreement was better in exposed children.