Interferon - (QIAREACH?) assay compatibility to Genexpert? MTB/Rif for lung tuberculosis diagnosis in children

Background: Diagnosing tuberculosis in children presents challenges due to inadequate specimen collection and paucibacillary TB cases in children, requiring more sensitive diagnostic methods to ensure accurate results. One commonly used diagnostic approach for paediatric patients is the TB scoring system, which incorporates a tuberculin test. Interferon-gamma release assay (IGRA) is another widely-used diagnostic tool that is more specific than tuberculin tests. We assessed the performance of a new portable IGRA device called QIAreach (R), in comparison to GeneXpert (R) MTB/RIF tests, for diagnosing paediatric TB. Methods:This descriptive, analytical study was carried out at Cipto Mangunkusumo Hospital in Jakarta and involved children aged 5 to 18 years with suspected pulmonary TB from November 2021 - May 2023. Results: Of 45 patients meeting the inclusion criteria and undergoing both tests, QIAreach (R) exhibited a sensitivity of 100% and specificity of 68.4%, with a positive predictive value of 36.8% and a negative predictive value of 100%. Conclusion: QIAreach (R) provides an additional consideration for diagnosing pediatric TB in Indonesia, as it demonstrates high sensitivity and acceptable specificity when compared to GeneXpert (R) MTB/RIF.