Session: Poster Session: Laboratory Testing for Mycobacteria
Sunday, October 26, 2008: 12:00 AM
Room: Hall C
Background: The aim of the present study was to assess the contribution of a QuantiFERON-TB Gold In-Tube test (QFT-IT) to the differentiation of active tuberculosis (TB) from latent tuberculosis infection (LTBI) by quantifying interferon-γ levels. Methods: We retrospectively reviewed clinical records from 314 patients older than 15 years who had QFT-IT performed between July 2006 and August 2007 at Severance Hospital, Yonsei University College of Medicine. Results: Subjects with active TB and positive results of QFT-IT (n=66) and LTBI (n=76) were included. Mean ±SD IFN-γ levels were: 6.06±3.59 (range 0.56 ~ 10) for subjects with active TB; 4.11±3.57(range 0.35 ~ 10) for subjects with LTBI. the quantitative results of the QFT-IT of subjects with active TB were different from that of LTBI with stastical significance.(P =0.001) Conclusion: Although production of IFN-γ, measured by QFT-IT correlated to some extent with activity of Mycobacterium tuberculosis infection, measuring IFN-γ using QFT-IT might not be useful for distinguishing active from LTBI because of the overlap of the quantitative results of the QFT-IT between subjects with active TB and LTBI.