Accurate detection of the latent form of tuberculosis (TB) infection remains a major clinical and public health problem worldwide, which in the United States, disproportionally affects minorities, foreign-born individuals and patients with weak immune defenses (e.g. patients with HIV infection andlor on immunosuppressive medications). We designed and validated a new method that detects specific lymphocyte markers (i.e. expression of CD25 and/or C0134 surface cell markers in CD3+CD4+ and/or CD3+CDR+ T-cells and other lymphocytes) in response to specific antigens or components of the Mycobacterium tuberculosis, the causative bacteria of TB. This novel laboratory technology is innovative because it has the potential to accurately diagnose latent TB with high likelihood of progression to active TB (TB reactivation potential) by detecting these specific lymphocyte markers in blood and body samples, which appear to be only present prior to bacterial clearance (i.e. before latent TB infection treatment). If our preliminary data is confirmed with further studies, this new laboratory test could represent a significant advancement in the fight against TB by improving patient selection for latent TB treatment (better stratification of patients with reactivation potential) and better selection of individuals for future TB vaccinations. If successful, this new test will likely change practice, and ultimately, enhance control of TB in the community and improve minority and global health.