Effect of HIV-1 infection on T-Cell-based and skin test detection of tuberculosis infection.
BACKGROUND
Two forms of the IFN-gamma release assay (IFNGRA) to detect tuberculosis infection are available, but neither has been evaluated in comparable HIV-infected and uninfected persons in a high tuberculosis incidence environment.


OBJECTIVE
To compare the ability of the T-SPOT.TB (Oxford Immunotec, Abingdon, UK), QuantiFERON-TB Gold (Cellestis, Melbourne, Australia), and Mantoux tests to identify latent tuberculosis in HIV-infected and uninfected persons.


METHODS
A cross-sectional study of 160 healthy adults without active tuberculosis attending a voluntary counseling and testing center for HIV infection in Khayelitsha, a deprived urban South African community with an HIV antenatal seroprevalence of 33% and a tuberculosis incidence of 1,612 per 100,000.


RESULTS
One hundred and sixty (74 HIV(+) and 86 HIV(-)) persons were enrolled. A lower proportion of Mantoux results was positive in HIV-infected subjects compared with HIV-uninfected subjects (p < 0.01). By contrast, the proportion of positive IFNGRAs was not significantly different in HIV-infected persons for the T-SPOT.TB test (52 vs. 59%; p = 0.41) or the QuantiFERON-TB Gold test (43 and 46%; p = 0.89). Fair agreement between the Mantoux test (5- and 10-mm cutoffs) and the IFNGRA was seen in HIV-infected people (kappa = 0.52-0.6). By contrast, poor agreement between the Mantoux and QuantiFERON-TB Gold tests was observed in the HIV-uninfected group (kappa = 0.07-0.30, depending on the Mantoux cutoff). The pattern was similar for T-SPOT.TB (kappa = 0.18-0.24).


CONCLUSIONS
IFNGRA sensitivity appears relatively unimpaired by moderately advanced HIV infection. However, agreement between the tests and with the Mantoux test varied from poor to fair. This highlights the need for prospective studies to determine which test may predict the subsequent risk of tuberculosis.
Rangaka
Molebogeng Xheeda
MX
Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory 7925, Cape Town, South Africa.
Wilkinson
Katalin A
KA
Seldon
Ronnett
R
Van Cutsem
Gilles
G
Meintjes
Graeme Ayton
GA
Morroni
Chelsea
C
Mouton
Priscilla
P
Diwakar
Lavanya
L
Connell
Tom G
TG
Maartens
Gary
G
Wilkinson
Robert J
RJ
D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D015488:HIV Antigens / Q000276:immunology*; D015658:HIV Infections / Q000150:complications / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D014505:Urban Population
D015488:HIV Antigens