Researchers from France and Columbia have identified tuberculosis-related molecules in exhaled breath condensate (EBC), pointing to a new noninvasive approach for diagnosing the disease at the point of care. TB, which is caused the pathogen Mycobacterium tuberculosis, remains a key cause of death worldwide. Still, an estimated one-third of TB cases go undiagnosed, in part because most tests rely on sputum samples, which can be difficult to obtain and have low diagnostic sensitivity in children, HIV-infected individuals, and patients with extrapulmonary TB. With the goal of developing a non-sputum-based TB diagnostic, the researchers examined whether pulmonary TB could be detected in EBC samples. As reported in Nature Communications this week, they show that M. tuberculosis-specific lipids lipoarabinomannan lipoglycan, and proteins in EBC can be used to differentiate TB patients from controls, either healthy or with community-acquired bacterial pneumonia. Notably, the biomarkers could also be used to track the longitudinal effects of antibiotic treatment in pediatric TB patients. The findings, the researchers write, "indicate that EBC analysis can potentially facilitate clinical diagnosis of TB across patient populations and monitor treatment efficacy."