clinical validation of interferon gamma release assay standard f tb-feron fia™ in hiv patients with and without tuberculosis

Interferon-gamma release assay (igra) is an in vitro test for evaluating the cellular immune response to mycobacterium tuberculosis. the world health organization (who) recommended quantiferon-tb gold plus (qft-tb gold plus) as one of the igra tests. standard f tb-feron fia biosensor (tbf-fia), another igra test, uses fluorescent immunoassay (fia) with fluorescent compounds as detectors. however, each new method should be validated with the established method. this study aims to validate and compare igra test results between the tbf-fia and qft-tb gold plus methods in hiv patients. this study was an observational analytical study. hiv patients at the dr. soetomo general hospital were tested using tbf-fia and qft-tb gold plus between february and may 2024. the concordance between the igra results was analysed. the results showed that the overall concordance of tbf-fia and qft-tb gold plus was 92.4% (k: 0.846, p < 0.001). the concordance in the hiv without tb group was 88.5% (k: 0.752, p < 0.001), indicating a high-level concordance, while in the hiv with tb group was 95.6% (k: 0.901, p < 0.001), and in the hiv-negative group was 93.3% (k: 0.85 p < 0.001), provided almost perfect concordances. this study showed there was an almost perfect concordance between tbf-fia and qft-plus as an overall performance, in the hiv with tb group and the hiv-negative group, while hiv without tb group had a high level of concordance. tbf-fia provided a rapid and practical alternative to the current igra test.