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

Abstract

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.

Quantitative Analysis of Gamma Interferon Release Assay Response in Children with Latent and Active Tuberculosis

“…Furthermore, the background IFN-␥ level and response to QFT-IT M. tuberculosis antigens could play a potential role in the differential diagnosis of latent and active TB in children. Our observations could be transferred to the new version of the test, QFT Plus, which has recently been shown to substantially agree with QFT-IT results and has similar sensitivity in active TB (49) but lacks data in children.…”

QuantiFERON-TB Gold PLUS versus QuantiFERON- TB Gold In-Tube test for diagnosing tuberculosis infection

“…We demonstrated here that the QFT-PLUS results were highly comparable to those of the QFT-GIT in immunocompromised subjects as well. Previous studies revealed that QFT-PLUS showed higher sensitivity in HIV and TB co-infected subjects than the QFT-GIT [20,27]. In this study, the majority of subjects had been assigned to an LTBI screening before biologic therapy Table 4…”

“…The QFT-PLUS contains two antigen tubes, TB1 and TB2: the TB1 tube contains ESAT-6-and CFP-10-derived peptides (TB 7.7 was removed) and is designed to induce CD4+ T cells response; the TB2 contains both the same long peptides of TB1 and newly designed peptides that stimulate IFN-γ production by both CD4+ and CD8+ T cells [18]. Recent studies have reported similar accuracies of QFT-PLUS and with QFT-GIT [17,[19][20][21][22], and some showed higher CD8+ T cell responses to recent Mtb exposure compared to remote exposure in contact screening [19,22].…”

Evaluation of the QuantiFERON-Tuberculosis Gold Plus Assay in Children with Tuberculosis Disease or Following Household Exposure to Tuberculosis

“…It was designed to increase the sensitivity for detecting the immune response to TB in subpopulations such as children, people living with HIV (PLHIV), and recently infected individuals. Thus far it has demonstrated similar performance characteristics to the QFT-GIT, among adults, [7][8][9][10][11] with limited data in subpopulations and some suggestion of benefit in PLHIV, recently infected individuals, and those with severe TB disease. 8,[12][13][14][15] Here, we evaluate the performance of the QFT-Plus compared with that of the QFT-GIT in a critical subpopulation of children with household exposure to TB disease and in those treated for TB disease.…”