The diagnostic accuracy of Quantiferon-TB Gold In-Tube (QFT-IT) is uncertain in the pediatric population, while tuberculin skin test (TST) is still conventionally used despite its limitations. The aim of this study was to compare the performance of QFT-IT with TST in a large cohort of children screened for tuberculosis (TB) infection because of contact tracing, suspected TB, arrival from endemic country or immunosuppressive therapy.
A retrospective analysis was conducted on 517 children 0–14 years of age evaluated at the pediatric unit of the S. Orsola-Malpighi University Hospital of Bologna, Italy; 366 of them were also tested with TST. Results were analyzed for Calmette-Guérin bacillus vaccination, country of origin, reason for testing, diagnosis and age.
The overall agreement between the 2 tests was 89.9%, but it was highly affected by Calmette-Guérin bacillus vaccination (P < .0001). According to diagnosis and age, QFT-IT detected latent tuberculous infection cases better than TST in all age groups. Sensitivity for diagnosing active TB in symptomatic children was higher for QFT-IT than TST (93.3% vs. 86.5%), especially in children younger than 2 years, while specificity was high for both tests (99.3% and 98.8%, respectively). Low rate of indeterminate QFT-IT results (3.9%) was not differently distributed among age groups, but was associated with diagnosis of TB exclusion (P < 0.0001), mainly pneumonia (35%), and to Italian children (P = 0.0024).
Despite the concern about the use of QFT-IT in children because of their immature immune system, our results suggest the preferential use of QFT-IT as a support tool for diagnosis and management of TB, even in infants.
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From the *Department of Medical and Surgical Sciences, Unit of Pediatrics, S. Orsola-Malpighi University Hospital, Bologna, Italy; †Department of Medical and Surgical Sciences, Unit of Microbiology, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola-Malpighi University Hospital, Bologna, Italy; ‡Unit of Pediatric Emergency, S. Orsola-Malpighi University Hospital, Bologna, Italy; and §Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola-Malpighi University Hospital, Bologna, Italy.
Accepted for publication June 23, 2016.
This study was partially supported by the contribution of the “Fondazione Del Monte of Bologna and Ravenna
The authors have no conflicts of interest to disclose.
The authors Petrucci and Lombardi equally contributed to this study.
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Address for correspondence: Giulia Lombardi, PhD, Unit of Microbiology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, St. Orsola Malpighi University Hospital, Via Massarenti 9, 40138 Bologna, Italy. E-mail: email@example.com.