Diagnosis of latent tuberculosis infection among HIV discordant partners using interferon gamma release assays

• Type of Material: Article
• Authors: Naasha J Talati, University of Pennsylvania; Esteban Gonzalez-Diaz, Hospital Civil de Guadalajara; Charles Mutemba, Zambia Emory HIV Research Project; Joyanna Wendt, Emory University; William Kilembe, Zambia Emory HIV Research Project; Lawrence Mwananyanda, Zambia Emory HIV Research Project; Elwyn Chomba, Zambia Emory HIV Research Project; Susan A Allen, Emory University; Carlos Del Rio, Emory University; Henry Michael Blumberg, Emory University
• Language: English
• Date: 2011-09-30
• Publisher: BioMed Central
• Publication Version: Final Published Version
• Copyright Statement: ©2011 Talati et al; licensee BioMed Central Ltd.
• License: Creative Commons Attribution 2.0 Generic
• Final Published Version (URL): http://dx.crossref.org/10.1186%2F1471-2334-11-264
• Title of Journal or Parent Work: BMC Infectious Diseases
• Volume: 11
• Start Page: 264
• End Page: 264
• Grant/Funding Information: Supported in part by Emory University Global Health Institute; NIH/Fogarty International Center (grants # D43 TW01042 & D43 TW007124); Emory Center for AIDS Research (P30A1050409), NIH/NCRR UL1RR025008 (for the Atlanta Clinical and Translational Science Institute), International AIDS Vaccine Initiative, NIAID R01.
• Research Categories: Health Sciences, Public Health; Health Sciences, Epidemiology

Abstract

Background There is limited data on the effect of HIV status and CD4 counts on performance of Interferon-g Release assays (IGRAs) for diagnosis of latent tuberculosis infection (LTBI). Methods A cross sectional study was conducted to assess the prevalence of and risk factors for a positive diagnostic test for LTBI, using tuberculin skin test (TST) and IGRAs among HIV-discordant couples in Zambia. Results A total of 596 subjects (298 couples) were enrolled. Median CD4 count among HIV positive persons was 388 cells/μl, (range 51-1330). HIV negative persons were more likely than their HIV positive partner, to have a positive diagnostic test for LTBI with TST (203 vs 128), QFT (171 vs 109) and TSPOT (156 vs. 109). On multivariate analysis, HIV negative status was an independent predictor for a positive QFT (OR = 2.22, 95% CI 1.42- 3.46) and TSPOT (OR = 1.79, 95% CI 1.16-2.77). Among HIV positive subjects a CD4 count ≥ 388 cells/μl was associated with a positive TST (OR = 1.76 95% CI 1.10-2.82) and QFT (OR = 1.71 95% CI 1.06-2.77) but not TSPOT (OR = 1.20 95% CI 0.74-1.94). Conclusions Persons with HIV had significantly fewer positive diagnostic tests for LTBI with TST, QFT and TSPOT. Persons with a CD4 count < 388 cells/μl were less likely to have a positive TST or QFT, but not less likely to have a positive TSPOT. TSPOT may perform better than TST or QFT in HIV positive individuals.