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Pulmonary Medicine
Volume 2013, Article ID 601737, 11 pages
http://dx.doi.org/10.1155/2013/601737
Review Article

Interferon-Gamma Release Assays versus Tuberculin Skin Testing for the Diagnosis of Latent Tuberculosis Infection: An Overview of the Evidence

1Gama Filho University, 20740-900 Rio de Janeiro, RJ, Brazil
2Montreal Chest Institute, McGill University, Montreal, QC, Canada H2X 2P4
3Federal University of Rio de Janeiro, 21941-913 Rio de Janeiro, RJ, Brazil

Received 5 October 2012; Accepted 10 January 2013

Academic Editor: Jonathan Golub

Copyright © 2013 A. Trajman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A profusion of articles have been published on the accuracy and uses of interferon-gamma releasing assays. Here we review the clinical applications, advantages, and limitations of the tuberculin skin test and interferon-gamma release assays and provide an overview of the most recent systematic reviews conducted for different indications for the use of these tests. We conclude that both tests are accurate to detect latent tuberculosis, although interferon-gamma release assays have higher specificity than tuberculin skin testing in BCG-vaccinated populations, particularly if BCG is received after infancy. However, both tests perform poorly to predict risk for progression to active tuberculosis. Interferon-gamma release assays have significant limitations in serial testing because of spontaneous variability and lack of a validated definition of conversion and reversion, making it difficult for clinicians to interpret changes in category (conversions and reversions). So far, the most important clinical evidence, that is, that isoniazid preventive therapy reduces the risk for progression to disease, has been produced only in tuberculin skin test-positive individuals.