Interferon Gamma Release Assay Compared With the Tuberculin Skin Test for Latent Tuberculosis Detection in Pregnancy

Duke University, Durham, North Carolina, United States
Obstetrics and Gynecology (Impact Factor: 5.18). 12/2011; 118(6):1363-70. DOI: 10.1097/AOG.0b013e31823834a9
Source: PubMed


To estimate agreement and correlation between the tuberculin skin test and an interferon gamma release assay for detecting latent tuberculosis (TB) infection in pregnant women.
We conducted a cross-sectional study of pregnant women initiating prenatal care at a university-affiliated public hospital between January 5, 2009, and March 15, 2010. Eligible women received a questionnaire about TB history and risk factors as well as the tuberculin skin test and phlebotomy for the interferon gamma release assay. Agreement and correlation between tests were estimated, and different cutoffs for interferon gamma release assay positivity were used to assess effect on agreement. Furthermore, predictors of test positivity and test discordance were evaluated using multivariable analysis.
Of the 220 enrolled women, 199 (90.5%) returned for tuberculin skin test evaluation. Over 70% were Hispanic and 65% were born in a country with high TB prevalence. Agreement between the tuberculin skin test and interferon gamma release assay was 77.39 (κ=0.26). This agreement was not significantly changed using different cutoffs for the assay. Birth bacille Calmette-Guérin vaccination was associated with tuberculin skin test positivity (odds ratio [OR] 4.33, 95% confidence interval [CI] 1.4-13.48, P=.01), but not interferon gamma release assay positivity. There were no statistically significant predictors of the tuberculin skin test and interferon gamma release assay result discordance; however, birth in a high-prevalence country was marginally associated with tuberculin skin test-positive and interferon gamma release assay-negative results (OR 2.94, 95% CI 0.86-9.97 P=.08).
Comparing the tuberculin skin test and interferon gamma release assay results in pregnancy, concordance and agreement were poor. Given that much is still unknown about the performance of interferon gamma release assays in pregnancy, further research is necessary before the tuberculin skin test is abandoned for screening of latent TB infection in pregnancy.

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Available from: Dennis Osmond, Mar 19, 2014
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    • "IGRAs demonstrate only fair concordance with the TST in pregnancy. Two US studies screening pregnant women for latent tuberculosis found that most discordance was IGRA negative/TST positive [27, 28] , attributed to previous BCG vaccination among the foreign-born [28]. In contrast, in India, discordance was largely IGRA positive/TST negative [24] . "
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    ABSTRACT: Tuberculosis is most common during a woman's reproductive years and is a major cause of maternal–child mortality. National guidelines for screening and management vary widely owing to insufficient data. In this article, we review the available data on (1) the global burden of tuberculosis in women of reproductive age; (2) how pregnancy and the postpartum period affect the course of tuberculosis; (3) how to screen and diagnose pregnant and postpartum women for active and latent tuberculosis; (4) the management of active and latent tuberculosis in pregnancy and the postpartum period, including the safety of tuberculosis medications; and (5) infant outcomes. We also include data on HIV/tuberculosis coinfection and drug-resistant tuberculosis. Finally, we highlight research gaps in tuberculosis in pregnant and postpartum women.
    Preview · Article · Aug 2012 · Clinical Infectious Diseases
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    ABSTRACT: To evaluate an interferon (IFN)-gamma release assay in diagnosing latent tuberculosis infection in pregnant adolescents and women at risk for exposure to Mycobacterium tuberculosis. This was a prospective study of women and adolescents receiving health care at Bellevue Hospital Outpatient Clinics in New York City. Each patient was assessed for M tuberculosis risk factors, had a tuberculin skin test placed, and an IFN-gamma release assay performed. The concordance between the tuberculin skin test and the IFN-gamma release assay was calculated and the results analyzed according to the likelihood of exposure to M tuberculosis. Mean mitogen IFN-γ levels were used across groups to compare reliability between trimesters and assay performance in pregnant compared with nonpregnant females of childbearing age. A total of 140 pregnant and 140 nonpregnant females were enrolled in the study. The IFN-gamma release assay was highly specific, and IFN-gamma release assay positivity was associated with a greater likelihood of exposure to M tuberculosis. The overall agreement between the tuberculin skin test and IFN-gamma release assay results was 88% for all pregnant patients, corresponding to a κ of 0.452 (confidence interval 0.26-0.64). Interferon-γ release from the mitogen did not appear to have any temporal association with pregnancy trimester in cross-sectional or longitudinal studies. The IFN-gamma release assay performed equally well in pregnant and nonpregnant females. The IFN-gamma release assay performed equally well in each trimester of pregnancy with comparable results to nonpregnant females. Interferon-gamma release assays are much more specific, at least as sensitive, and may be a better predictor of disease progression than the tuberculin skin test. : II.
    Full-text · Article · May 2012 · Obstetrics and Gynecology

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