TY - JOUR
T1 - Whole blood interferon-gamma assay for baseline tuberculosis screening among Japanese healthcare students
AU - Hotta, Katsuyuki
AU - Ogura, Toshio
AU - Nishii, Kenji
AU - Kodani, Tsuyoshi
AU - Onishi, Masaru
AU - Shimizu, Yukito
AU - Kanehiro, Arihiko
AU - Kiura, Katsuyuki
AU - Tanimoto, Mitsune
AU - Tobe, Kazuo
PY - 2007/8/29
Y1 - 2007/8/29
N2 - Background. The whole blood interferon-gamma assay (OuantIPER0N-TB-2G:QFT) has not been fully evaluated as a baseline tuberculosis screening test in Japanese healthcare students commencing clinical contact. The aim of this study was to compare the results from the QFT with those from the tuberculin skin test (TST) in a population deemed to be at a low risk for infection with Mycobacterium tuberculosis. Methodology/Principal Findigs. Healthcare students recruited at Okayama University received both the TST and the QFT to assess the level of agreement between these two tests. The interleukin-10 levels before and after exposure to M tuberculosis-specific antigens {early-secreted antigenic target 6-kDa protein [ESAT-6] and culture filtrate protein 10 [CFP-10]) were also measured. Of the S36 healthcare students, most of whom have been vaccinated with bacillus-Calmette-Guérin (BCG), 207 MOM were enrolled in this, study. The agreement between the QFT and the TST results was poor, with positive result rates of 1.4% vs. 27,5%, respectively. A multivariate analysis also revealed that the induration diameter of the TST was not affected by the interferon-gamma concentration after exposure to either of the antigens but was influenced by the number of BCG needle scars (p=0.046). The whole blood interieukin-10 assay revealed that after antigen exposure, the median increases in Interknukln-10 concentration was higher in the subgroup with the small increase in interferon-gamma concentration than in the subgroup with the large increase in interferon-gamma concentration (0.3 vs. 0 pg/ml; p=0.004). Conclusions/Significance. As a baseline screening test for low-risk Japanese healthcare students at their course entry, QFT yielded quite discordant results, compared with the TST, probably because of the low specificity of the TST results in the BCG-vaccinated population. We also found, for the first time, that the change in the interieukin-10 level after exposure to specific antigens was inversely associated with that in the interferon-gamma level in a low-risk population.
AB - Background. The whole blood interferon-gamma assay (OuantIPER0N-TB-2G:QFT) has not been fully evaluated as a baseline tuberculosis screening test in Japanese healthcare students commencing clinical contact. The aim of this study was to compare the results from the QFT with those from the tuberculin skin test (TST) in a population deemed to be at a low risk for infection with Mycobacterium tuberculosis. Methodology/Principal Findigs. Healthcare students recruited at Okayama University received both the TST and the QFT to assess the level of agreement between these two tests. The interleukin-10 levels before and after exposure to M tuberculosis-specific antigens {early-secreted antigenic target 6-kDa protein [ESAT-6] and culture filtrate protein 10 [CFP-10]) were also measured. Of the S36 healthcare students, most of whom have been vaccinated with bacillus-Calmette-Guérin (BCG), 207 MOM were enrolled in this, study. The agreement between the QFT and the TST results was poor, with positive result rates of 1.4% vs. 27,5%, respectively. A multivariate analysis also revealed that the induration diameter of the TST was not affected by the interferon-gamma concentration after exposure to either of the antigens but was influenced by the number of BCG needle scars (p=0.046). The whole blood interieukin-10 assay revealed that after antigen exposure, the median increases in Interknukln-10 concentration was higher in the subgroup with the small increase in interferon-gamma concentration than in the subgroup with the large increase in interferon-gamma concentration (0.3 vs. 0 pg/ml; p=0.004). Conclusions/Significance. As a baseline screening test for low-risk Japanese healthcare students at their course entry, QFT yielded quite discordant results, compared with the TST, probably because of the low specificity of the TST results in the BCG-vaccinated population. We also found, for the first time, that the change in the interieukin-10 level after exposure to specific antigens was inversely associated with that in the interferon-gamma level in a low-risk population.
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U2 - 10.1371/journal.pone.0000803
DO - 10.1371/journal.pone.0000803
M3 - Article
C2 - 17726533
AN - SCOPUS:41049091729
VL - 2
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 8
M1 - e803
ER -