2017 年 243 巻 3 号 p. 205-210
Japan is still designated as a medium incidence country, worldwide. Although the definitive diagnosis of tuberculosis is made by detecting pathogen from tissue specimens, collecting those from children is physically difficult. Therefore, we must frequently depend on the results of tuberculin skin test (TST) or interferon-gamma release assay (IGRA). However, the value of IGRA in diagnosing tuberculosis in infants remains unclear. We implemented TST and IGRA concurrently and examined the significance of combining these two tests by analyzing cases where conflicting results were evident from other tests. Subjects included 52 children (24 boys, 28 girls) age 15 years or younger (4.0 ± 3.4 years) who visited our hospital for close examination after medical checkup for tuberculosis contact tracing. The children underwent TST, T-SPOT®.TB, chest plain radiography, and chest computed tomography with a view to tuberculosis diagnosis during a 26-months period from January 2013 to March 2015. T-SPOT results were positive in 9/52 cases (17.3%), and TST results were positive in 12/52 cases (23.1%). Conflicting results were observed in 7/52 cases (13.5%), and all cases were treated as latent tuberculosis infection or incident cases of tuberculosis. The value of T-SPOT in tuberculosis diagnosis in children is still being established. However, there are a number of cases where conflicting results for T-SPOT and TST are indicated. Thus, it is currently desirable to use T-SPOT and TST concomitantly for children at an early age, especially for children below the age of 5 years, as a diagnostic measure in complementing other techniques.
