The Role of Interferon-gamma Release Assay in Tuberculosis Control

Abstract

The Role of Interferon-gamma Release Assay in Tuberculosis ControlTuberculosis is still one of the major global public health threats. Countries with low incidence must focus on exhausting the reservoir of future cases by preventing reactivation. Therefore, it is important to identify and effectively treat those individuals who have latent tuberculosis infection and who may develop active disease. The tuberculin skin test has been the standard for detection of immune response against M. tuberculosis since the beginning of the 20th century. The new millennium has brought advancement in the diagnosis of latent tuberculosis infection. The name of the new blood test is interferon-gamma release assay (IGRA). Croatia is a middle-incidence country with a long decreasing trend and developed tuberculosis control. To reach low incidence and finally eliminate tuberculosis, its tuberculosis programme needs a more aggressive approach that would include intensive contact investigation and treatment of persons with latent tuberculosis infection. This article discusses the current uses of IGRA and its role in tuberculosis control.

The influence of single nucleotide polymorphisms of NOD2 or CD14 on the risk of Mycobacterium tuberculosis diseases: a systematic review

“…This polymorphism is located in the promoter region of the CD14 gene [ 9 ], and the T allele seems to act as a negative regulator of in vitro T-cell proliferation and decreased production of cytokines, including interferon-y (IFN-γ) [ 28 ]. IFN-γ is an essential cytokine for the control of mycobacterial infection [ 39 ], and therefore, rs2569190 may produce an environment that favors development of TB. Interestingly, other studies found this SNP associated with ischemic stroke [ 40 ], cardiovascular disease [ 41 ], and asthma [ 42 ], indicating that these polymorphisms could actually lead to a more profound alteration in immune responses that may affect a large number of clinical conditions.…”

The Influence of Single Nucleotide Polymorphisms of NOD2 or CD14 on Susceptibility to Tuberculosis: A Systematic Review

“…This polymorphism is located in the promoter region of the CD14 gene [35] and the T allele was attributed to a negative regulator of in vitro T-cell proliferation and decreased production of cytokines, including interferon-y (IFN-γ) [26]. IFN-γ is an essential cytokine for the control of mycobacterial infection [36], and for that reason it is possible to hypothesize that rs2569190 may result in an environment that favors development of TB. Interestingly, other studies also related this SNP with occurrence of ischemic stroke [37], cardiovascular disease [38] and asthma [39], indicating that these polymorphisms could actually lead to a more profound alteration in immune responses that may affect a large number of clinical conditions.…”

Determinación del interferón-gamma en tuberculosis: Principios básicos y utilidad

“…Hay estudios que indican que se precisa de una exposición continua frente a MTB para mantener una respuesta IGRA elevada en contactos de casos de TB. 32 Se ha demostrado en algunos estudios que los niveles de IFN-γ no se reducen significativamente aun posterior a la administración de antifímicos de forma profiláctica, razón para no recomendar la utilización del IGRA con fines de monitorización de la terapia preventiva en casos de ITBL. 32,33 Por otro lado, generalmente el manejo quimioprofiláctico en contactos de casos de TB ha llevado a una reducción en los niveles de IFN-γ, empero sólo en una pequeña proporción se alcanzó la reversión.…”

“…32 Se ha demostrado en algunos estudios que los niveles de IFN-γ no se reducen significativamente aun posterior a la administración de antifímicos de forma profiláctica, razón para no recomendar la utilización del IGRA con fines de monitorización de la terapia preventiva en casos de ITBL. 32,33 Por otro lado, generalmente el manejo quimioprofiláctico en contactos de casos de TB ha llevado a una reducción en los niveles de IFN-γ, empero sólo en una pequeña proporción se alcanzó la reversión. 34 Existe información obtenida de varios estudios que revela una reducción en los niveles de IFN-γ subsecuente a un tratamiento antifímico exitoso en pacientes con TBA, aunque en menos del 50% se logró una reversión, este fenómeno ha sido observado particularmente en individuos con valores basales bajos de IFN-γ, PCR, así como fiebre al momento del diagnóstico de TBA.…”