title: First evaluation of QuantiFERON-TB Gold Plus performance in contact screening.
abstract: Identifying latently infected individuals is crucial for the elimination of tuberculosis (TB). We evaluated for the first time the performance of a new type of interferon-γ release assay, QuantiFERON-TB Plus (QFT-Plus), which includes an additional antigen tube (TB2), stimulating both CD4+and CD8+T-cells in contacts of TB patients.Contacts were screened for latent TB infection by tuberculin skin test, QFT-Plus and QuantiFERON-TB Gold in Tube (QFT-GIT).In 119 TB contacts, the overall agreement between QFT-Plus and QFT-GIT was high, with a Cohen's κ of 0.8. Discordant results were found in 12 subjects with negative QFT-GIT and positive QFT-Plus results. In analyses of markers of TB exposure and test results, the average time spent with the index case was the strongest risk factor for positivity in each of these tests. The difference in interferon-γ production between the two antigen tubes (TB2-TB1) was used as an estimate of CD8+stimulation provided by the TB2. TB2-TB1 values >0.6 IU·mL-1were significantly associated with proximity to the index case and European origin.QFT-Plus has a stronger association with surrogate measures of TB exposure than QFT-GIT in adults screened for latent TB infection. Interferon-γ response in the new antigen tube used an indirect estimate of specific CD8+response correlates with increased Mycobacterium tuberculosis exposure, suggesting a possible role in identifying individuals with recent infection.
authors.affiliation: Emerging Bacterial Pathogens Unit, Division of Immunology and Infectious Diseases IRCCS, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Barcellini
authors.affiliation: Emerging Bacterial Pathogens Unit, Division of Immunology and Infectious Diseases IRCCS, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Borroni
authors.affiliation: Royal Free London NHS Trust and UCL Respiratory, Division of Medicine, University College London, London, UK.
authors.forename: James
authors.initials: J
authors.lastname: Brown
authors.affiliation: Dept of Infectious Diseases, San Matteo Hospital Foundation, University of Pavia, Pavia, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Brunetti
authors.affiliation: Regional TB Reference Centre and Laboratory, Villa Marelli Institute/Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Campisi
authors.affiliation: Regional TB Reference Centre and Laboratory, Villa Marelli Institute/Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Paola F
authors.initials: PF
authors.lastname: Castellotti
authors.affiliation: Regional TB Reference Centre and Laboratory, Villa Marelli Institute/Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Luigi R
authors.initials: LR
authors.lastname: Codecasa
authors.affiliation: University Centre of Statistics for Biomedical Sciences (CUSSB), Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Cugnata
authors.affiliation: University Centre of Statistics for Biomedical Sciences (CUSSB), Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Clelia
authors.initials: C
authors.lastname: Di Serio
authors.affiliation: Regional TB Reference Centre and Laboratory, Villa Marelli Institute/Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferrarese
authors.affiliation: Translational Research Unit, Epidemiology Dept, National Institute for Infectious Diseases, Rome, Italy.
authors.forename: Delia
authors.initials: D
authors.lastname: Goletti
authors.affiliation: Royal Free London NHS Trust and UCL Respiratory, Division of Medicine, University College London, London, UK.
authors.forename: Marc
authors.initials: M
authors.lastname: Lipman
authors.affiliation: University Centre of Statistics for Biomedical Sciences (CUSSB), Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Paola M V
authors.initials: PM
authors.lastname: Rancoita
authors.affiliation: Emerging Bacterial Pathogens Unit, Division of Immunology and Infectious Diseases IRCCS, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Russo
authors.affiliation: Infectious Diseases Unit, Dept of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Tadolini
authors.affiliation: Infectious Diseases Unit, Dept of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Vanino
authors.affiliation: Emerging Bacterial Pathogens Unit, Division of Immunology and Infectious Diseases IRCCS, San Raffaele Scientific Institute, Milan, Italy cirillo.daniela@hsr.it.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Cirillo
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D016358:Contact Tracing / Q000379:methods*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007371:Interferon-gamma; D059425:Interferon-gamma Release Tests / Q000379:methods*; D007558:Italy; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009169:Mycobacterium tuberculosis; D014374:Tuberculin Test / Q000379:methods; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis
chemical_list: D007371:Interferon-gamma