Relationship between whole-blood interferon-gamma responses and the risk of active tuberculosis.
We have analyzed the relationship between the responses to the diagnostic method for Mycobacterium tuberculosis (Mtb) infection, QuantiFERON-TB Gold (QFT-G), and the risk of developing active tuberculosis (TB). Contacts under 42 years old who were exposed to a patient with infectious pulmonary TB were tested using QFT-G during an investigation. Among 172 contacts, 111 (64.5%) were QFT-G positive. All subjects were evaluated for active TB by chest X-ray examination and, if needed, by CT scan at the time of the QFT-G test and 39 were diagnosed with active TB based on radiological abnormalities consistent with TB. Of these, 35 (89.7%) were QFT-G positive. Statistically the geometric mean of interferon-gamma (IFN-gamma) production levels of the active TB group was significantly larger than that of the latent TB infection group (p=0.013). The results of the multivariate analysis clearly showed that a combined parameter of ESAT-6 and CFP-10 significantly contributes to disease risk for the infected subjects. Our results suggest that subjects with high levels of IFN-gamma production in response to either ESAT-6 and/or CFP-10 in the QFT-G test have a higher possibility of developing active TB than QFT-G positive subjects with lower levels of IFN-gamma.
Higuchi
Kazue
K
Immunology Division, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, 3-1-24, Matsuyama, Kiyose, Tokyo 204-8533, Japan. higuchi@jata.or.jp
Harada
Nobuyuki
N
Fukazawa
Keiji
K
Mori
Toru
T
D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D002648:Child; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011859:Radiography; D012307:Risk Factors; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging / Q000276:immunology* / Q000635:transmission
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007371:Interferon-gamma