Academic Commons

Articles

Sensitivity Analysis and Potential Uses of a Novel Gamma Interferon Release Assay for Diagnosis of Tuberculosis

Tsiouris, Simon; Coetzee, David; Toro, Patricia L.; Austin, Judith; Stein, Zena A.; El-Sadr, Wafaa Mahmoud

Sputum smears for acid-fast bacilli (AFB) are the primary methods for diagnosis of tuberculosis (TB) in many countries. The tuberculin skin test (TST) is the primary method for diagnosis of latent TB infection (LTBI) worldwide. The poor sensitivity of the former and the poor specificity of the latter warrant the development of new tests and strategies to enhance diagnostic capabilities. We evaluated the sensitivity of an “in-tube” gamma interferon release assay (IGRA) using TB-specific antigens in comparison to the TST and the sputum smear for AFB in TB cases in South Africa. The sensitivity of the IGRA for TB was considered a surrogate of sensitivity in LTBI. Among 154 patients with a positive culture for Mycobacterium tuberculosis, the sensitivity of the IGRA for the diagnosis of TB varied by clinical subgroup from 64% to 82%, that of the TST varied from 85% to 94%, and that of two sputum smears for AFB varied from 35% to 53%. The sensitivity of the IGRA in human immunodeficiency virus (HIV)-infected TB cases was 81%. HIV-infected TB patients were significantly more likely to have indeterminate IGRA results and produced quantitatively less gamma interferon in response to TB-specific antigens than HIV-negative TB patients. The overall sensitivity of the TST in all TB cases was higher than that of the IGRA (90% versus 76%, respectively). The combined sensitivities of the TST plus IGRA and TST plus a single sputum smear were 96% and 93%, respectively. The TST combined with IGRA or with a single sputum smear may have a role in excluding the diagnosis of TB in some settings.

Subjects

Files

  • thumnail for J._Clin._Microbiol.-2006-Tsiouris-2844-50.pdf J._Clin._Microbiol.-2006-Tsiouris-2844-50.pdf application/pdf 77.1 KB Download File

Also Published In

Title
Journal of Clinical Microbiology
DOI
https://doi.org/10.1128/JCM.02411-05

More About This Work

Academic Units
Epidemiology
Population and Family Health
International Center for AIDS Care and Treatment Programs
Publisher
American Society for Microbiology
Published Here
October 16, 2015
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.