Tuberculosis skin test, but not interferon-γ-releasing assays is affected by BCG vaccination in HIV patients

Prevalence of latent tuberculosis infection in persons with and without human immunodeficiency virus infection using two interferon-gamma release assays and tuberculin skin test in a low human immunodeficiency virus prevalence, intermediate tuberculosis-burden country

“…Discordance between TST and IGRA with TSTþ/IGRAÀ results was strongly associated with cross-reactivity with NTM and BCG vaccination status, especially in low TB endemic areas and in populations with low risk for TB exposure. 34 A clear proportional relationship was observed between T cell count and the level of IFN-g response in those with CD4 cell count <500 cells/mL. 36 The higher prevalence of LTBI among HIV infected, using TST (23.0%, 95% CI: 13.2e32.8) compared with IGRA (10.5%, 95% CI: 3.9e17.1), in our study may be due to false reactivity associated with BCG vaccination.…”

“…36 The higher prevalence of LTBI among HIV infected, using TST (23.0%, 95% CI: 13.2e32.8) compared with IGRA (10.5%, 95% CI: 3.9e17.1), in our study may be due to false reactivity associated with BCG vaccination. 16,34,35 False-positive TST results increase the cost of TB screening with additional procedures such as chest radiographs and unnecessary drug treatment. 37 Discordant TSTe/QFT þ results (5/91, 5.5%) may be attributable to either false-positive QFT results or better sensitivity of IGRAs over TST.…”

“…The reliability and validity of TST and IGRAs can be influenced by several confounding factors, including the immune status, cross-reactions to BCG or NTM, and the prevalence local TB burden. 34 To increase the PPV and reduce the number of false positives, the use of a risk-stratified interpretation, as has been used for TST, was suggested. 38 We suggest that the use of TST alone may not be accurate in the diagnosis of LTBI in HIV-infected persons, especially in patients who had received BCG vaccination.…”

Evaluation of a domestic interferon-gamma release assay for detecting Mycobacterium tuberculosis infection in China

“…The diagnosis of MTB infection is very important to control TB epidemics, such as the investigation and control of TB outbreaks [9], surveillance of high risk populations [10,11], and epidemiological study of LTBI [12,13]. Because there is no diagnostic gold standard for MTB infection, it is difficult to accurately evaluate the performance of an assay to diagnose MTB infection, especially LTBI.…”

Tuberculosis Testing in Children

“…More studies are needed to determine if this should also be the approach for testing in the pediatric HIV population. 25…”