Performance of an Advanced Interferon-Gamma Release Assay for Mycobacterium tuberculosis Detection

Area of Science:

• Immunodiagnostics
• Infectious disease diagnostics
• Clinical chemistry

Background:

• The LIAISON QuantiFERON-TB Gold Plus (QFT-Plus) assay is a new automated chemiluminescence immunoassay (CLIA) for interferon-gamma (IFN-γ) detection.
• FDA approval has been granted for this assay on the LIAISON XL analyzer.

Purpose of the Study:

• To evaluate the diagnostic performance of the LIAISON CLIA assay.
• To compare the LIAISON CLIA assay against the established Qiagen QuantiFERON-TB Gold Plus ELISA method.

Main Methods:

• Heparinized blood samples from 329 participants across three cohorts (active TB, low-risk, mixed-risk) were analyzed.
• Both the LIAISON CLIA and Qiagen ELISA assays were used for sample analysis.
• Results were interpreted based on manufacturer criteria.

Main Results:

• The LIAISON CLIA assay showed high overall agreement with the Qiagen ELISA across all cohorts (>92%).
• Cohen's kappa values indicated substantial to excellent agreement between the two assays (0.74-0.88).
• Discrepant results were minimal, with three samples negative by ELISA but positive by CLIA.

Conclusions:

• The automated LIAISON QFT-Plus CLIA assay exhibits comparable diagnostic performance to the Qiagen ELISA method.
• The findings support the use of the LIAISON QFT-Plus assay for diagnosing latent TB infection (LTBI).
• The assay's automation and performance make it a viable option for TB diagnostics.