Diagnostic performance of interferon-gamma releasing assay in HIV-infected patients in China.
BACKGROUND
Active tuberculosis infection represents a very common and significant threat to HIV-infected patients. But measures to accurately detect it are limited.


OBJECTIVE
To compare and analyze the diagnostic efficacy of T-SPOT.TB alone and in combination with TST in HIV-infected patients in China.


METHODS
TST (tuberculin skin test) and T-SPOT.TB were performed on 131 HIV-infected patients admitted in Beijing You'an Hospital and Beijing Ditan Hospital between Oct, 2010 and Jul, 2012, who were initially diagnosed as suspected ATB (active TB). The patients were further categorized into ATB and Not ATB based on clinical and cultural evidences. The performance of TST and T-SPOT.TB were analyzed and compared.


RESULTS
The sensitivity and specificity of T-SPOT.TB were 41.3% and 94.6%, respectively, both higher than TST (12.9% and 91.8%). By combining T-SPOT.TB and TST, the sensitivity did not increase, but specificity was elevated to 100%. TST, T-SPOT.TB and their combinations all performed better in patients with extra-pulmonary diseases than with pulmonary disorders. False-positive T-SPOT.TB results were found to be associated with history of prior TB. In addition, concomitant bacterial infections and low CD4 counts were associated with increased ATB risk.


CONCLUSIONS
T-SPOT.TB is superior in screening ATB in HIV-infected patients in China over traditional TST. Additional TST would help to confirm a positive T-SPOT.TB result. Both tests work better for patients with extra-pulmonary conditions.
Department of Clinical Laboratory, Beijing You'an Hospital, Capital Medical University, Beijing, China.
Yanhua
Y
Yu
Xiuying
X
Zhao
Wen
W
Wang
Hao
H
Wu
Ming
M
Chen
Wenhao
W
Hua
Huizhu
H
Wang
Ting
T
Wei
Yanmei
Y
Jiao
Guizhen
G
Sun
Wei
W
Li
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006678:HIV / Q000276:immunology* / Q000472:pathogenicity; D015658:HIV Infections / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D059425:Interferon-gamma Release Tests / Q000592:standards*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity; D011446:Prospective Studies; D012307:Risk Factors; D014374:Tuberculin Test / Q000592:standards*; D014376:Tuberculosis / Q000175:diagnosis* / Q000209:etiology
D007371:Interferon-gamma