J Korean Med Sci.  2019 Oct;34(40):e259. 10.3346/jkms.2019.34.e259.

Good Agreement between an Interferon Gamma Release Assay and Tuberculin Skin Tests in Testing for Latent Tuberculosis Infection among HIV-Infected Patients in Indonesia

• Reviono R
• Saptawati
• Redhono D
• Suryawati

• KMID: 2460035
• DOI: http://doi.org/10.3346/jkms.2019.34.e259

Abstract

BACKGROUND
Latent tuberculosis infection is a condition where there is a persistent immune response to Mycobacterium tuberculosis without clinical manifestations of tuberculosis. Currently, there is no gold standard to diagnose latent tuberculosis infection. The tuberculin skin test and interferon-gamma release assay are currently used to diagnose latent tuberculosis infection. However, studies have shown inconsistencies regarding the level of agreement between these tests in different settings. In this study, we aimed to evaluate the agreement between these two tests for diagnosing latent tuberculosis infection in human immunodeficiency virus (HIV)-infected individuals.
METHODS
We screened HIV patients with no clinical symptoms of tuberculosis, a normal chest X-ray, and no history of tuberculosis or use of antituberculous drugs. Participants were tested with tuberculin skin test (TST) and T-SPOT.TB (an interferon gamma release assay) simultaneously. Participants' HIV stage was determined by measuring the level of CD4+ T-lymphocytes. Tuberculosis status was confirmed by sputum examination using GeneXpert. The level of agreement between the TST and T-SPOT.TB results was measured using Cohen's κ coefficient.
RESULTS
Of the 112 participants, 20 had a positive T-SPOT.TB test result, and 21 had a positive TST result. The TST and T-SPOT.TB test results showed a high level of agreement (κ = 0.648, P < 0.001). Performance of the tests did not vary with CD4+ level. However, in participants with CD4+ < 200 cells/mm³, T-SPOT.TB detected more latent tuberculosis infections than the TST.
CONCLUSION
There was good agreement between the TST and T-SPOT.TB results of latent tuberculosis infection in participants. TST is the preferred test for diagnosing latent tuberculosis infection in HIV-infected patients, especially in resource-limited settings, because it is simple and cost-effective. However, T-SPOT.TB may be useful to rule out latent tuberculosis infection in patients with severe immunodeficiency.

Keyword

Latent Tuberculosis Infection; Human Immunodeficiency Virus; T-SPOT.TB; Tuberculin Skin Test; Tuberculosis

MeSH Terms

HIV
Humans
Indonesia*
Interferon-gamma Release Tests
Interferons*
Latent Tuberculosis*
Mycobacterium tuberculosis
Skin Tests*
Skin*
Sputum
T-Lymphocytes
Thorax
Tuberculin*
Tuberculosis
Interferons
Tuberculin