Taurine, glycine, tryptophan and kynurenine are key metabolic signatures for differentiation of extrapulmonary pleural tuberculosis

Tuberculosis (TB) is one of the leading causes of mortality in humans with clinical manifestations as pulmonary and extrapulmonary forms. TB pleural effusion (PlTB) is one of the main forms of extrapulmonary TB, which is challenging to diagnose due to overlapping clinical symptoms with other non-TB pleural effusions and poses severe complications in treatment and management of disease. We urgently need novel biomarkers to improve diagnostics for PlTB. Here we conducted a high-throughput 96 well plate-based targeted LC-MS/MS metabolomics to quantify metabolic signatures in serum and pleural fluid of PlTB patients. We identified taurine, glycine, tryptophan and kynurenine as the top metabolites for differentiation of PlTB from pulmonary TB and non-TB pleural effusions. Our work provides a new metabolomic assay for biomarker analysis and identifies important metabolic signatures that will advance diagnostics for accurate detection of PlTB.