Related Experiment Video
Updated: Jun 17, 2026
Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-α
Published on: June 14, 2018
Interferon-γ release assay as an emergent powerful biomarker in systemic lupus erythematosus
Yves Renaudineau1,2, Emmanuel Treiner1,2, Fabrice Herin2,3
1Immunology Department Laboratory, Referral Medical Biology Laboratory, Institut Fédératif de Biologie, Toulouse University Hospital, Toulouse, France.
Objectives:
To investigate the ex vivo IFN-γ release assay (IGRA) as a biomarker of systemic lupus erythematosus (SLE) activity and disease outcome.
Methods:
This retrospective study, conducted between 2008 and 2024 at a single tertiary care centre, included 145 SLE patients at various disease stages. Data were collected on spontaneous IFN-γ levels (IGRA-nil) and on phytohemagglutinin-induced IFN-γ levels (IGRA-PHA, after subtracting the IGRA-nil result).
Results:
The ex vivo spontaneous IFN-γ release was increased (IGRA-nil; P = 0.0004) and the PHA-induced IFN-γ release was decreased in active SLE patients (IGRA-PHA; P < 10-4), regardless of treatment, including glucocorticoids. Nephritis, serositis, constitutional symptoms, mucocutaneous and musculoskeletal manifestations were associated with impaired IGRA-PHA release (P < 0.05 for each association). An IGRA-PHA ≥ 8.0 IU/ml, corresponding to the optimal Youden index, predicted clinically inactive SLE better than IGRA-nil (area under the curve = 0.853 vs 0.722) and IGRA-PHA <1.6 IU/ml indicated 100% specificity for active disease. Moreover, IGRA-PHA ≥ 8.0 IU/ml was an independent predictor of clinically inactive SLE in multivariate regression analysis (OR: 10.6 [95% CI: 3.72-30.17]; P = 9.7 × 10-6), and IGRA-PHA ≤1.6 IU/ml was associated with a longer time to achieve remission in a log-rank test (P = 2.4 × 10-6).
Conclusion:
The IGRA-PHA assay appears to be a powerful and independent biomarker for clinically active SLE, when performed at the initiation or intensification of therapy, and as a predictor of treatment-induced remission at therapy evaluation.
