Positive Tuberculin Skin Test or Interferon-Gamma Release Assay in Patients with Radiographic Lesion Suggesting Old Healed Tuberculosis

Abstract

Radiographic lesions suggesting old healed tuberculosis (TB) is considered a risk factor for the subsequent development of active TB. The aim of this study was to estimate the positive rates of tuberculin skin test (TST) and interferon-gamma release assay (IGRA) in persons with old healed TB. Participants with lesions suggesting old healed TB on chest images and controls without such lesions were prospectively enrolled between January 1, 2010, and January 31, 2011. TST and the QuantiFERON-TB Gold In-Tube test (QFT-GIT) were performed. In total, 193 participants with old healed TB and 126 controls were recruited. The rates of positive TST and QFT-GIT among patients with old healed TB were 54.6% and 77.7%, respectively. The rates of positive TST and QFT-GIT among patients without old healed TB were 38.9% and 61.9%. Sixteen percent of participants with old healed TB showed negative results by both TST and QFT-GIT. The positive rate of TST waned among participants with old healed TB who were older than 60 yr, whereas QFT-GIT positivity was unaffected by age. The positive rates of TST and IGRA among participants with radiographic lesions suggesting old healed TB was higher than without those lesions. In addition, IGRA may be more accurate than TST for the detection of latent TB infection, especially in populations of individuals older than 60 yr.

Use of inhaled corticosteroids and the risk of tuberculosis

“…However, in that study, because the majority of ICS users were unlikely to have had LTBI, the impact of ICS use on the reactivation of TB among patients with LTBI may have been underestimated 14. In South Korea, the prevalence of LTBI, defined by positive interferon γ release assay among people older than 60 years without old, healed TB on chest radiography, was 67% in 2010 31. Analysis of a larger cohort consisting of 853 439 new users of inhaled respiratory medication in South Korea, an intermediate-TB-burden country, confirmed that ICS use could increase the risk of development of TB.…”

A comparative analysis of two interferon-γ releasing assays to detect past tuberculosis infections in Japanese rheumatoid arthritis patients

“…Tuberculin skin test (TST) and interferon-g (IFN-g) release assays (IGRAs) are the main tests currently available for the diagnosis of LTBI. Several previous reports proposed that IGRAs may be more accurate and useful tools than TST for detecting LTBI among RA patients [4][5][6][7][8]. At present, QuantiFERON-TB Gold in tube (QFT-GIT) and T-SPOT.TB assays are available as commercial IGRA kits in Japan.…”

“…It is critical to evaluate LTBI as well as past exposure to TB and the radiographic signs of past TB infection to determine the need for prophylactic anti-TB drugs, such as isoniazid before treating RA with immunosuppressive DMARDs, such as methotrexate (MTX) and biologics, to reduce the risk of reactivation of TB [2][3][4][5]. Tuberculin skin test (TST) and interferon-g (IFN-g) release assays (IGRAs) are the main tests currently available for the diagnosis of LTBI.…”

Assessment of a Protein Cocktail-Based Skin Test for Bovine Tuberculosis in a Double-Blind Field Test in Cattle

“…Importantly, shared antigenic components in PPD-B and nonpathogenic environmental mycobacteria can reduce the specificity of the tuberculin skin test (7,8). Although the gamma interferon (IFN-␥) release assay (IGRA) showed higher specificity than the single intradermal skin test, the high price of this kit limits its use in developing countries such as China (9,10). To overcome the drawbacks of the traditional diagnostic methods, scientists have focused on screening new M. bovis-specific antigens to substitute for PPD-B as stimuli in the skin test (11)(12)(13).…”