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

Abstract

To compare the QuantiFERON-TB GOLD In Tube test (QTF) and the tuberculin skin test (TST) in children. 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). 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). 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.