Consensus-based evaluation of RIDASCREEN® TB ELISA compared with two interferon-gamma release assays in a low-incidence setting
摘要
Interferon-gamma release assays (IGRAs) are widely used to detect Mycobacterium tuberculosis infection by measuring antigen-specific T-cell responses through interferon-gamma (IFN-γ) release. Interferon gamma-induced protein 10 (IP-10), an IFN-inducible cytokine released in higher concentrations after antigen stimulation, may improve assay robustness and sensitivity. We evaluated the performance of the novel IP-10–based RIDASCREEN® TB in comparison with T-SPOT® TB and QuantiFERON®-TB Gold Plus (QFT®-Plus).
MethodsIn this prospective study, 209 patients undergoing routine T-SPOT® TB testing at AZ Sint-Jan Hospital Bruges were included. For each participant, T-SPOT® TB, QFT®-Plus, and RIDASCREEN® TB were performed. In the absence of a diagnostic gold standard, assay performance was assessed using a consensus classification defined by agreement between at least two of the three assays. Overall, positive, and negative percent agreement and kappa values were calculated relative to the consensus.
ResultsAccording to the consensus classification, 19/209 (9.1%) samples were positive, 186/209 (89.0%) negative, and 2/209 (1.0%) equivocal. Full three-way concordance was observed in 83.7% of patients, and true discordance was uncommon (7.7%). RIDASCREEN® TB showed a higher positivity rate (12.9%) than T-SPOT® TB (8.7%) and QFT®-Plus (7.7%). Agreement with the consensus classification was high for all assays, with overall percent agreement of 98.4% for T-SPOT® TB, 97.5% for QFT®-Plus, and 96.6% for RIDASCREEN® TB.
ConclusionRIDASCREEN® TB showed high agreement with established IGRAs and may improve detection of low-level immune responses. Its higher positivity rate may reflect increased sensitivity rather than reduced specificity.