New Strategies for Assessment of the Persistence of Viable Bacilli in Latent and Active Tuberculosis

Current diagnostic tools such as interferon gamma release assay (IGRA) and purified protein derivative (PPD) can not distinguish patients with latent tuberculosis infection (LTBI) and persistence of live mycobacteria. This inability to rule out living mycobacteria in patients investigated for LTBI leads to unnecessary and potentially harmful treatment regimes all around the globe.The goal of this observational study is to identify candidate biomarkers for viable bacilli in latent tuberculosis in order to decrease the use of unnecessary and ineffective antibiotic treatment.

LTBI (2 groups)Inclusion Criteria:latent tuberculosis: Interferon gamma (IFN-γ) >0.70 IU/ml in the Quantiferon-TB Plus assayage 15-25 years OR high likelihood of recent TB transmissioninformed consentExclusion Criteria:active tuberculosischronic illnessimmunosuppressive treatmentpregnancy (including 6 months post-partum)previous treatment for either active or latent TB infectionControlsInclusion Criteria:age 15-25 yearsinformed consentExclusion Criteria:latent- OR active tuberculosischronic illnessimmunosuppressive treatmentpregnancy (including 6 months post-partum)previous treatment for either active or latent TB infectionActive TBInclusion Criteria:diagnosed with active TBinformed consentExclusion Criteria:age < 15 years