Objectives The aim of this verification study was to compare the QuantiFERON®-TB Gold Plus (QFT-Plus) to the QuantiFERON®-TB Gold In Tube (QFT-GIT). The new QFT-Plus test contains an extra antigen tube which, according to the manufacturer additionally elicits a CD8+ T-cell response above the CD4+ T-cell response. We assessed the value of this tube in detecting recent latent tuberculosis infections. Methods Between May 2015 and December 2016, 1031 subjects underwent QFT-Plus and QFT-GIT test. Overall agreement between both tests and performance for different test indications and/or immune states was assessed. A difference of >0.6 IU/mL interferon-γ release between the two antigen tubes of the QFT-Plus assay was considered a true difference and used as estimation for CD8+ T-cell response. Results Analysis of the QuantiFERON tests resulted in an overall agreement between assays of 95%. Subjects considered to be recently exposed to tuberculosis had significantly more often a true difference in interferon-γ release compared to all other subjects (p = 0.029). Conclusion Results of QFT-Plus are highly comparable to QFT-GIT. Although there is an indication that a true difference in interferon-γ release between the antigen tubes is associated with recent latent tuberculosis infection, the QFT-Plus could not be used to exclude recent exposure.

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Keywords Interferon-gamma release assay, Latent tuberculosis infection, QuantiFERON-TB Gold In Tube, QuantiFERON-TB Gold Plus, Tuberculosis
Persistent URL dx.doi.org/10.1016/j.tube.2017.11.014, hdl.handle.net/1765/103328
Journal Tuberculosis
Pieterman, E.D. (E. D.), Liqui Lung, F.G. (F. G.), Verbon, A, Bax, H.I, Ang, C.W. (C. W.), Berkhout, J, … de Steenwinkel, J.E.M. (2018). A multicentre verification study of the QuantiFERON®-TB Gold Plus assay. Tuberculosis, 108, 136–142. doi:10.1016/j.tube.2017.11.014