Detection and prediction of active tuberculosis disease by a whole-blood interferon-gamma release assay in HIV-1-infected individuals.
BACKGROUND
The sensitivity of whole-blood interferon-gamma release assays to detect or predict active tuberculosis in individuals infected with human immunodeficiency virus type 1 (HIV-1) has as yet not been determined. Methods. In this prospective, longitudinal, single-center study, 830 HIV-1-infected patients underwent testing with the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay. Clinical screening for active tuberculosis was performed at least every 3 months for a median follow-up time of 19 months.


RESULTS
At baseline, the QFT-GIT assay yielded positive or indeterminate results in 44 (5.3%) and 47 (5.7%) of the 830 patients, respectively. A positive QFT-GIT assay result occurred at significantly higher frequencies among black individuals than among white individuals (odds ratio, 4.84; 95% confidence interval, 2.25-9.97; P< .001), among patients from Africa than among patients from Austria (odds ratio, 6.57; 95% confidence interval, 2.99-14.25; P< .001), and among patients from high-prevalence countries than among patients from low-prevalence countries (odds ratio, 5.86; 95% confidence interval, 2.41-13.44; P< .001). In patients with indeterminate QFT-GIT assay results, both median actual and nadir CD4(+) T cell counts were significantly lower than in patients with interpretable QFT-GIT assay results (P< .001). At the time of baseline QFT-GIT screening, active tuberculosis was found in 7 (15.9%) of 44 individuals with a positive result and in 1 (0.1%) of 739 patients with a negative result. During the follow-up period, however, progression to active tuberculosis occurred exclusively in patients with a positive QFT-GIT assay result, at a rate of 8.1% (3 of 37 patients; P< .001). Collectively, the sensitivity of the QFT-GIT assay for active tuberculosis was 90.9% (95% confidence interval, 62.3%-98.4%).


CONCLUSIONS
Our results suggest that the QFT-GIT assay may be a sensitive tool for the detection and prediction of active tuberculosis in HIV-1-infected individuals.
Aichelburg
Maximilian C
MC
Department of Dermatology, Division of Immunology, Allergy, and Infectious Diseases, Vienna General Hospital, Medical University of Vienna, Vienna, Austria.
Rieger
Armin
A
Breitenecker
Florian
F
Pfistershammer
Katharina
K
Tittes
Julia
J
Eltz
Stephanie
S
Aichelburg
Alexander C
AC
Stingl
Georg
G
Makristathis
Athanasios
A
Kohrgruber
Norbert
N
D000328:Adult; D000349:Africa; D001317:Austria; D018791:CD4 Lymphocyte Count; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D044469:Racial Groups; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult
D007371:Interferon-gamma