Identification of Lipid Biomarkers for Skeletal Tuberculosis Using an Untargeted Metabolomics Approach

Abstract BackgroundThe identification of novel biomarkers in the human body is urgently needed to improve diagnosis and the clinical management of skeletal tuberculosis (STB). This study aimed to identify potential lipid markers to differentiate Mycobacterium tuberculosis infection from other infections, and establish a metabolite biomarker panel suitable for STB diagnosis from abscess samples.MethodsParticipants were recruited from Beijing Chest Hospital between January 2018 and December 2019. Abscess specimens were collected from STB patients and patients diagnosed with other skeletal infections. Then we comparatively explored the lipid metabolomes of abscess specimens from STB and non-STB patients using untargeted lipid metabolomics approach.ResultsA total of 957 features in ESI + mode and 584 in ESI– mode were extracted from the lipidomic data. Among 1541 lipid metabolites, 55 lipid metabolites were significantly changed in STB patients compared to the control group. Significant up-regulation was clearly visualized in phosphatidylethanolamine, phosphatidylinositol, lysophatidylinositols, lysophosphatidylcholines and lysophosphatidylethanolamine. Concomitantly, triacylglycerols and phosphatidylcholines were significantly down-regulated in patients affected by STB. It is worth noting that the two down-regulated monoacyl chain phosphatidylcholine, triacylglycerols and one up-regulated LPE showed excellent diagnostic potential, the AUC values of which were higher than 0.9 and the highest value was 1.0. ConclusionsTo conclude, our data firstly characterize the lipid signatures of abscess specimens from STB patients. The LPEs are significantly upregulated in the STB cases than those in non-STB control, whereas phosphocholines and triacylglycerol are markedly downregulated in the STB cases. The panel of five lipid biomarkers exhibits great capacity for differential diagnosis of STB and non-TB cases.