Distinguishing tuberculosis from Mycobacterium avium complex disease using an interferon-gamma release assay

• Published in: The international journal of tuberculosis and lung disease Vol. 15; no. 5; pp. 635 - 640
• Main Authors: RA, S. W, LYU, J, CHOI, C.-M, OH, Y.-M, LEE, S.-D, KIM, W. S, KIM, D. S, SHIM, T. S
• Format: Journal Article
• Language: English
• Published: Paris, France IUATLD 01.05.2011; International Union against Tuberculosis and Lung Disease
• Subjects: Adult; Aged; Aged, 80 and over; Bacterial diseases; Biological and medical sciences; Female; Human bacterial diseases; Humans; Infectious diseases; Interferon-gamma - blood; Interferon-Gamma Release Assay; Male; Medical sciences; Middle Aged; Mycobacterium avium; Mycobacterium avium Complex - immunology; Mycobacterium avium Complex - isolation & purification; Mycobacterium Avium-Intracellulare Infection; Mycobacterium avium-intracellulare Infection - diagnosis; Mycobacterium avium-intracellulare Infection - immunology; Mycobacterium tuberculosis - immunology; Mycobacterium tuberculosis - isolation & purification; Pneumology; Prospective Studies; Respiratory system : syndromes and miscellaneous diseases; Sensitivity and Specificity; Tuberculin Test - methods; Tuberculosis; Tuberculosis - diagnosis; Tuberculosis - immunology; Tuberculosis and atypical mycobacterial infections; Young Adult; interferon-gamma release assay; Disease; Respiratory disease; Mycobacterium avium; Mycobacterial infection; Mycobacterium intracellulare; Complexes; Infection; Assay; Tuberculosis; Mycobacteriales; Mycobacterium avium-intracellulare infection; Bacteriosis; Mycobacteriaceae; Bacteria; Actinomycetes; Release; Gamma interferon; Pneumology
• ISSN: 1027-3719; 1815-7920
• DOI: 10.5588/ijtld.10.0485

SETTING: The QuantiFERON®-TB Gold (QFT-G) test can be used to distinguish between tuberculosis (TB) and non-tuberculous mycobacterial disease, but a high background TB infection rate may pose a problem. Although the QuantiFERON®-TB (QFT) test, the first-generation QFT-G test, employs a non-specific PPD antigen, avium sensitin is also used as a stimulating antigen.OBJECTIVE: To evaluate the utility of these two interferon gamma release assays (IGRAs), QFT-G and QFT, and the tuberculin skin test (TST), to differentiate TB from Mycobacterium avium complex (MAC) disease in an intermediate TB burden country.METHODS: We compared the diagnostic performance of these three tests in 38 prospectively enrolled patients with TB and 40 with MAC lung disease.RESULTS: The TST yielded positive results in 70.6% of TB and 47.5% of MAC patients; the proportions were respectively 89.5% and 34.3% for QFT-G and 86.8% and 35.3% for QFT. The three tests were of similar accuracy, sensitivity and specificity in diagnosing TB.CONCLUSION: Our findings indicate that the TST and IGRAs could not discriminate between active TB and MAC disease or latent TB infection in a TB-endemic area.