Decreased serum 5-oxoproline in TB patients is associated with pathological damage of the lung

Background: Tuberculosis (TB) is a serious world-wide health problem, causing millions of deaths every year. Metabolomics is a relatively new approach to identify disease specific biomarkers. However, there is little information available on metabolite biomarkers in TB. In this study, we used gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS) to identify serum metabolite biomarkers associated with the active state of TB. Methods: Potential biomarkers were selected by comparing serum metabolites in 10 healthy donors with 10 TB patients, and in 6 TB patients before and after treatment Selected biomarkers were then validated using a larger population of samples from 120 healthy donors and 120 TB patients derived from different clinical backgrounds Results: The 5-oxoproline level was consistently low in patients with active TB. Further validation in larger population of clinical samples showed that 5-oxoproline was associated with pathological damage of the lung but not with age, sex, or bacterial burden in TB patients. Conclusions: Serum 5-oxoproline may be a useful biomarker for active TB and pathological damage of the lung. (C) 2013 Elsevier B.V. All rights reserved.