Validation and clinical application of interferon-gamma release assay for diagnosis of latent tuberculosis infection in children

Abstract

Background:India has the highest tuberculosis (TB) burden, accounting for one-fifth of the global incidence and two-third of the cases in Southeast Asia with an estimated 1.9 million new cases every year. Identifying and treating latent TB infection (LTBI) can reduce the risk of development of active disease by up to 90%, thereby decreasing a major burden to the prevalence of the disease, and thus reducing potential sources in future.Aim:Early diagnosis of LTBI by tuberculin skin test (TST) and a newer interferon-gamma release assay (IGRA).Materials and Methods:Seventy-seven clinically asymptomatic household contacts (≤18 years) of confirmed pulmonary TB patients were enrolled to compare the performance of TST and IGRA to diagnose LTBI. At baseline, all participants underwent testing for IGRA and TST.Results:TST showed positivity of 22%, while IGRA demonstrated positivity of 40% in the diagnosis of latent TB. Kappa value at 95% confidence interval was 0.4753, indicates a moderate agreement between the two tests. This indicates that IGRA is a better predictor of latent TB. Maximum positive percentage was in the age group of 16–18 years in both the tests followed by 1–5 years.Aim:Early diagnosis of LTBI by tuberculin skin test (TST) and a newer interferon-gamma release assay (IGRA).

QuantiFERON-TB Gold Plus Test in Diagnostics of Latent Tuberculosis Infection in Children Aged 1–14 in a Country with a Low Tuberculosis Incidence

“…The authors claimed that the QFT-Plus test was more sensitive than TST for the population of children on immunosuppression. Benachinmardi et al (2019) obtained more positive results with IGRA test (E TB-feron) than with TST, and the Kappa coefficient was 0.4753. Our results are similar to these from Belgium, the country with a low TB incidence: 8.6/100,000.…”

Tuberculosis diagnostics: overcoming ancient challenges with modern solutions

“…These tests are known to be prone to false positives, and thus a combined use with culture methods enables a more accurate diagnosis. Though limitations become prominent when used in HIV, immunocompromised, paediatric or latent patients [48,49]. Additionally, molecular or immunological assays are costly to deploy and require a good level of expertise and suitable infrastructure to be implemented as evident by their high uptake in high-income countries, such as the United Kingdom yet, almost negligible uptake in countries such as India [50], which often lack such infrastructure.…”