In vitro immunomodulation for enhancing T cell–based diagnosis of Mycobacterium tuberculosis infection

• Published in: Diagnostic microbiology and infectious disease Vol. 83; no. 1; pp. 41 - 45
• Main Authors: Slater, Madeline, Tran, Minh-Chi, Platt, Lauren, Luu, Lien T, Phan, Ha T, Pham, Phuong T, Do, Tam B, Nguyen, Hanh T, Gaur, Rajiv L, Parsonnet, Julie, Cattamanchi, Adithya, Luo, Robert, Nahid, Payam, Banaei, Niaz
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2015
• Subjects: Adult; Aged; Female; Health Personnel; Humans; Immunologic Factors - metabolism; Infectious Disease; Interferon gamma release assays; Interferon-gamma Release Tests - methods; Internal Medicine; Lipopolysaccharides - metabolism; Male; Middle Aged; Mycobacterium tuberculosis; Mycobacterium tuberculosis - immunology; Pathogen associated molecular patterns; Poly I-C - metabolism; Prospective Studies; Quantiferon; Sensitivity and Specificity; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; Tuberculosis; Tuberculosis - diagnosis; United States; Vietnam; Interferon gamma release assays; Tuberculosis; Quantiferon; Pathogen associated molecular patterns
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2015.05.007

Abstract Interferon-gamma release assays have limited sensitivity for detecting latent tuberculosis infection. In this study, we determine if the addition of immunomodulators to the QuantiFERON-TB Gold In-Tube (QFT-GIT) increased test sensitivity without compromising specificity. We prospectively compared QFT-GIT results with and without incubation with 2 immunomodulators (lipopolysaccharide [LPS] and polyinosine-polycytidylic acid [PolyIC]) in 2 cohorts—113 culture-confirmed tuberculosis (TB) subjects in Hanoi, Vietnam, and 226 documented QFT-GIT–negative, low TB risk health care workers undergoing annual TB screening at a US academic institution. Sensitivity of the tests in TB subjects was 84.1% with the standard QFT-GIT and 85.8% and 74.3% after incubation with LPS and PolyIC, respectively. Specificity in low TB risk health care workers was 100% with the standard QFT-GIT by design and 86.7% with LPS and 63.3% with PolyIC. In conclusion, use of the 2 immunomodulators did not improve sensitivity of the QFT-GIT in TB patients and reduced specificity in low-risk health care workers.