Analytical evaluation of QuantiFERON- Plus and QuantiFERON- Gold In-tube assays in subjects with or without tuberculosis

• Published in: Tuberculosis (Edinburgh, Scotland) Scotland), 2017-09, Vol.106, p.38-43
• Main Authors: Petruccioli, E., Vanini, V., Chiacchio, T., Cuzzi, G., Cirillo, D.M., Palmieri, F., Ippolito, G., Goletti, D.
• Format: Article
• Language: English
• Subjects: Adult; Antigens, Bacterial - immunology; Bacterial Load; Bacterial Proteins - immunology; Biomarkers - metabolism; Case-Control Studies; CD4 antigen; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - metabolism; CD8-Positive T-Lymphocytes - microbiology; Cross-Sectional Studies; Diagnosis; Female; Host-Pathogen Interactions; Humans; Interferon-gamma - immunology; Interferon-gamma - metabolism; Interferon-gamma Release Tests - methods; Latency; Latent Tuberculosis - diagnosis; Latent Tuberculosis - immunology; Latent Tuberculosis - microbiology; Lymphocyte Activation; Lymphocytes T; Male; Medical diagnosis; Middle Aged; Mycobacterium tuberculosis - immunology; Mycobacterium tuberculosis - pathogenicity; Peptide Fragments - immunology; Peptides; Predictive Value of Tests; Quantiferon; Quantiferon plus; Reproducibility of Results; Severity of Illness Index; Tuberculosis
• ISSN: 1472-9792; 1873-281X
• DOI: 10.1016/j.tube.2017.06.002

The QuantiFERON-TB Gold Plus (QFT-Plus) represents the new QuantiFERON-TB Gold In-tube (QFT-GIT) to identify latent tuberculosis infection (LTBI). The main differences is the addition of a new tube containing shorter peptides stimulating CD8 T-cells. Aim of this study is to evaluate the accuracy of QFT-Plus compared with QFT-GIT in a cross sectional study of individuals with or without tuberculosis (TB). We enrolled 179 participants: 19 healthy donors, 58 LTBI, 33 cured TB and 69 active TB. QFT-Plus and QFT-GIT were performed. The two tests showed a substantial agreement. Moreover we found a similar sensitivity in active TB and same specificity in healthy donors. A higher proportion of the LTBI subjects responded to both TB1 and TB2 compared to those with active TB (97% vs 81%). Moreover, a selective response to TB2 was associated with active TB (9%) and with a severe TB disease, suggesting that TB2 stimulation induces a CD8 T-cell response in absence of a CD4-response. In conclusion, QFT-Plus and QFT-GIT assays showed a substantial agreement and similar accuracy for active TB detection. Interestingly, a higher proportion of the LTBI subjects responded concomitantly to TB1 and TB2 compared to those with active TB, whereas a selective TB2 response associated with active TB.