Preliminary diagnostic performance of the VIDAS® TB-IGRA for the detection ofMycobacterium tuberculosisinfection and disease

Abstract

ImportanceAccurate diagnosis of tuberculosis (TB) infection can be achieved with interferon-γ release assays. Their performance can be improved by utilizing fully automated, single-patient formats.ObjectiveEstablish clinical thresholds for a new interferon-γ release assay, the VIDAS® TB-IGRA, and compare diagnostic performance in detecting tuberculosis infection and disease with the established QuantiFERON-TB Gold Plus (QFT-Plus).DesignPreliminary diagnostic performance study (October 2nd, 2019–February 20th, 2020).SettingMulticenter.ParticipantsParticipants were divided into TB disease, high-risk, and low-risk populations. The confirmed TB disease population included 107 patients. The high-risk population included 162 individuals with flagged risk factors on a questionnaire but without objective clinical confirmation of TB. The Low-risk population included 117 healthy blood donors from the French National Blood Bank.ExposuresTuberculosis.Main Outcomes and MeasuresPositive and negative percent agreement (PPA, NPA) were determined between the VIDAS® TB-IGRA and QFT-Plus. In the TB disease and low-risk populations, sensitivity was also measured against bacterial culture and PCR.ResultsThe VIDAS® TB-IGRA produced fewer indeterminate results than the QFT-Plus (1/107 vs. 23/107) in the TB disease population. One analysis included indeterminate results as false negatives (94 positives and 10 false negatives vs. 56 positives and 48 false negatives), and the VIDAS® TB-IGRA exhibited higher sensitivity than the QFT-Plus (90.4% vs. 53.8%) (p<0.0001). Another analysis excluded indeterminate results (76 positives and 4 false negatives vs. 55 positives and 25 false negatives), and the VIDAS® TB-IGRA again exhibited higher sensitivity than the QFT-Plus (95.0% vs. 68.8%) (p<0.0001). A 98.2% PPA was calculated between the two tests with this dataset.In the high-risk population, the VIDAS® TB-IGRA exhibited a strong PPA (94.4%) with the QFT-Plus. However, a lower than expected NPA was observed (85.2%). In the low-risk population, the VIDAS® TB-IGRA demonstrated high specificity (94.9%) and a strong NPA (98.2%) with the QFT-Plus.Conclusions and RelevanceThe fully automated VIDAS® TB-IGRA is a promising diagnostic test for both TB infection and disease. It exhibits higher sensitivity while maintaining specificity and produces fewer indeterminate interpretations. Its easy-to-use, single-patient format may lead to increased TB testing to help with the worldwide eradication of the disease.KEY POINTSQuestionWhat is the diagnostic performance of the VIDAS® TB-IGRA in detecting tuberculosis infection and disease?FindingsThe VIDAS® TB-IGRA exhibited high sensitivity in individuals with tuberculosis disease (90.4–95.0%), high specificity in healthy blood donors (94.9%), a high positive percent agreement (PPA) in individuals with a high risk of tuberculosis infection (94.4%), and it produced a low number of indeterminate results (1/386).MeaningThe VIDAS® TB-IGRA is a promising diagnostic test for both tuberculosis infection and disease.

VIDAS®TB-IGRA accuracy in tuberculosis patients and persons at varying risk of exposure

“…A limitation of this study is that study participants were recruited from only two countries with high TB-incidence rates, South Africa and Mexico. However, the results obtained in this study are similar to those from a previous study [41] with, notably, 101 patients with TB disease from Burkina Faso (a high TB-incidence country) as well as France and the US, showing that VIDAS ® TB-IGRA had consistently higher sensitivity than QFT-Plus, with fewer indeterminate results.…”