Comparison of Two Interferon-Gamma Release Assays for Pediatric Tuberculosis Infection

Le résumé fourni par la source

INTRODUCTION: Identifying tuberculosis infection (TBI) using interferon-gamma release assays (IGRAs) is a primary component of clinical and public health efforts to prevent pediatric tuberculosis (TB). Pediatric data comparing the 2 IGRAs in the United States are very limited. We compared the performance of the 2 IGRAs among a large pediatric cohort tested for TBI and assessed whether discordance might be due to quantitative results close to test cutoff values. METHODS: Children aged 0-15 years with both T-SPOT.TB (T-SPOT) and QuantiFERON-TB Gold In-Tube (QFT-GIT) tests were identified from a US multicenter study enrolling people at elevated risk of TBI or progression to TB disease. Results were compared using McNemar's Chi-square tests with stratification by age category and testing reason. Percent agreement and kappa statistics were also calculated. We characterized quantitative test results among children with discordant QFT-GIT-positive/T-SPOT-negative results. RESULTS: Among 3793 children, a higher number had positive QFT-GIT than T-SPOT (10.1% vs 7.4%, P < .001). This difference was noted for all age categories except <2 years, and for children with close-contact and non-close contact test indications. Among discordant QFT-GIT-positive/T-SPOT-negative children, lowering the positive threshold for T-SPOT to include borderline spot counts (5-7) did not eliminate the discordance, nor were QFT-GIT antigen-minus-nil results concentrated in the range just above the standard cutoff of 0.35 IU/mL. CONCLUSIONS: In a large pediatric cohort tested for TBI, QFT-GIT had a higher proportion of positive results than T-SPOT, and discordance was not related to quantitative results close to the established diagnostic cutoffs.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.