title: Impact of tuberculosis treatment and antiretroviral therapy on serial RD-1-specific quantitative T-cell readouts (QuantiFERON-TB Gold In-Tube), and relationship to treatment-related outcomes and bacterial burden.
abstract: BACKGROUND
  The impact of anti-tuberculosis treatment with and without antiretroviral therapy (ART) on standardized interferon gamma release assay (IGRA) readouts has been studied inadequately in high-burden countries.
  
  
  METHODS
  The QuantiFERON-TB Gold In-Tube (QFT-GIT) test was used to evaluate interferon gamma (IFN-γ) responses longitudinally (0, 3, 6, and 12 months post initiation of tuberculosis (TB)-HIV co-treatment or ART alone) in 82 HIV-infected patients.
  
  
  RESULTS
  Of the 65 evaluable participants, 30 were co-infected on ART, 17 were co-infected but not on ART, and 18 were HIV-infected alone and on ART. In HIV-infected and HIV-TB-infected patients on ART, IFN-γ responses increased, whilst they decreased in those not on ART. However, baseline, month 3, and month 6 IFN-γ responses, irrespective of ART, did not differ in TB-HIV co-infected patients who culture-converted compared to those who did not (1.25 vs. 1.05, p=0.5 at baseline; 3.76 vs. 1.15, p=0.2 for month 3; 0.06 vs. 0.7, p=0.3 for month 6). IFN-γ levels did not correlate with the magnitude of sputum bacillary load, smear status, or liquid culture time-to-positivity.
  
  
  CONCLUSIONS
  As IGRAs do not correlate with 2- or 6-month culture conversion or with markers of bacillary burden, they are unlikely to be useful for the prognostication of treatment outcome in co-infected patients.
authors.affiliation: South African Medical Research Council, Parow Valley, Cape Town, South Africa.
authors.forename: Thuli
authors.initials: T
authors.lastname: Mthiyane
authors.affiliation: South African Medical Research Council, Parow Valley, Cape Town, South Africa.
authors.forename: Roxana
authors.initials: R
authors.lastname: Rustomjee
authors.affiliation: KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), Nelson Mandela School of Medicine, Durban, South Africa.
authors.forename: Alex
authors.initials: A
authors.lastname: Pym
authors.affiliation: South African Medical Research Council, Biostatistics Department, Durban, South Africa.
authors.forename: Cathy
authors.initials: C
authors.lastname: Connolly
authors.affiliation: World Health Organization/Special Programme for Research and Training in Tropical diseases (TDR), Geneva, Switzerland.
authors.forename: Philip
authors.initials: P
authors.lastname: Onyebujoh
authors.affiliation: Lung Infection and Immunity Unit, Division of Pulmonology, Department of Medicine, University of Cape Town, J flr, Old Main Bldg, Groote Schuur Hospital, Observatory, Cape Town, 7925, South Africa.
authors.forename: Grant
authors.initials: G
authors.lastname: Theron
authors.affiliation: Lung Infection and Immunity Unit, Division of Pulmonology, Department of Medicine, University of Cape Town, J flr, Old Main Bldg, Groote Schuur Hospital, Observatory, Cape Town, 7925, South Africa. Electronic address: keertan.dheda@uct.ac.za.
authors.forename: Keertan
authors.initials: K
authors.lastname: Dheda
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D000995:Antitubercular Agents / Q000627:therapeutic use; D060085:Coinfection / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D059425:Interferon-gamma Release Tests; D008137:Longitudinal Studies; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D013601:T-Lymphocytes / Q000276:immunology; D016896:Treatment Outcome; D014376:Tuberculosis / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology
chemical_list: D019380:Anti-HIV Agents; D000995:Antitubercular Agents; D007371:Interferon-gamma
keywords: Antiretrovirals; HIV; Interferon gamma release assay; QuantiFERON-TB Gold In-Tube; Tuberculosis