Interferon-γ Release Assay Performance for Tuberculosis in Childhood.

Area of Science:

• Pediatric infectious diseases
• Diagnostic immunology
• Public health surveillance

Background:

• Interferon-γ release assays (IGRAs) are crucial diagnostic tools for tuberculosis (TB) in pediatric populations.
• Understanding IGRA performance in children is essential for accurate TB diagnosis.

Purpose of the Study:

• To evaluate the performance and sensitivity of IGRAs compared to tuberculin skin tests (TSTs) in children diagnosed with TB.
• To identify factors associated with IGRA test selection and indeterminate results in pediatric TB cases.

Main Methods:

• Analysis of California TB registry data from 2010-2015 for laboratory-confirmed TB cases in individuals ≤18 years old.
• Comparison of IGRA and TST sensitivity across different age groups (<2, 2-4, and 5-18 years).
• Multivariable analysis to determine characteristics associated with indeterminate IGRA results.

Main Results:

• Indeterminate IGRAs were significantly associated with younger age (<1 year) and central nervous system TB.
• In children aged 5-18 years, IGRA sensitivity (96%) was significantly higher than TST (83%).
• IGRA and TST sensitivities were comparable in children aged 2-4 years and reduced in those <2 years old.

Conclusions:

• IGRAs demonstrate superior sensitivity to TSTs in children ≥5 years old with confirmed TB, supporting their use as a preferred diagnostic test.
• In children <5 years old, IGRA sensitivity is comparable to TST, though both tests show reduced sensitivity in infants <2 years old.
• Indeterminate IGRA results are more frequent in infants <1 year and in cases of central nervous system TB, highlighting specific population considerations.