IngentaConnect Waning of the specific interferon-gamma response after years of t...

Authors: Mori, T.¹; Harada, N.²; Higuchi, K.²; Sekiya, Y.³; Uchimura, K.²; Shimao, T.²

Source: The International Journal of Tuberculosis and Lung Disease, Volume 11, Number 9, September 2007 , pp. 1021-1025(5)

Publisher: International Union Against Tuberculosis and Lung Disease

Abstract:

HYPOTHESIS: Memory T-cell responses to specific antigens wane over time in subjects with tuberculosis (TB) infection.

SETTING: Accumulated evidence indicates that QuantiFERON^®-TB Gold (QFT-G), a specific whole-blood interferon-gamma (IFN-γ) based assay, can detect recent TB infections with superior sensitivity and specificity.

OBJECTIVE: We applied this technique to the adult population of a Japanese community to determine its epidemiological usefulness.

METHOD: A total of 1559 subjects attending periodic health screening volunteered to participate in the study.

RESULTS: The QFT-G positive rates were 3.1% for those aged 40-49 years, 5.9% for those aged 50-59 and 9.8% for those aged 60-69. The expected infection prevalence estimated by the authors from a series of studies was 11.1%, 29.6% and 53.1% for those aged 40-49, 50-59 and 60-69 years, respectively. This wide gap between the expected and observed positivity suggests that the IFN-γ response waned substantially with time after infection. Those with X-rays suggestive of old TB lesions exhibited positivity rates well below 100%.

CONCLUSION: The specific IFN-γ response may wane considerably with time after infection. Longitudinal studies are required to investigate long-term dynamics of cell-mediated immunity in infected donors.

Keywords: tuberculosis infection; interferon-gamma; diagnostic; epidemiology; tuberculin skin test

Document Type: Regular paper

Affiliations: 1: Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan; Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan 2: Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan 3: Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan; Laboratory of Immunoregulation, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan

Waning of the specific interferon-gamma response after years of tuberculosis infection