ABSTRACT

Pleural effusion is a common respiratory disease worldwide; however, rapid and accurate diagnoses of tuberculosis pleural effusion (TPE) and malignancy pleural effusion (MPE) remain challenging. Although extracellular vesicles (EVs) have been confirmed as promising sources of disease biomarkers, little is known about the metabolite compositions of its subpopulations and their roles in the diagnosis of pleural effusion. Here, we performed metabolomics and lipidomics analysis to investigate the metabolite characteristics of two EV subpopulations derived from pleural effusion by differential ultracentrifugation, namely large EVs (lEVs, pelleted at 20,000 × g) and small EVs (sEVs, pelleted at 110,000 × g), and assessed their metabolite differences between tuberculosis and malignancy. A total of 579 metabolites, including amino acids, acylcarnitines, organic acids, steroids, amides and various lipid species, were detected. The results showed that the metabolic profiles of lEVs and sEVs overlapped with and difference from each other but significantly differed from those of pleural effusion. Additionally, different type of vesicles and pleural effusion showed unique metabolic enrichments. Furthermore, lEVs displayed more significant and larger metabolic alterations between the tuberculosis and malignancy groups, and their differential metabolites were more closely related to clinical parameters than those of sEV. Finally, a panel of four biomarker candidates, including phenylalanine, leucine, phosphatidylcholine 35:0, and sphingomyelin 44:3, in pleural lEVs was defined based on the comprehensive discovery and validation workflow. This panel showed high performance for distinguishing TPE and MPE, particularly in patients with delayed or missed diagnosis, such as the area under the receiver-operating characteristic curve (AUC) >0.95 in both sets. We conducted comprehensive metabolic profiling analysis of EVs, and further explored the metabolic reprogramming of tuberculosis and malignancy at the level of metabolites in lEVs and sEVs, providing insight into the mechanism of pleural effusion, and identifying novel biomarkers for diagnosing TPE and MPE.

 抽象的

胸腔积液是世界范围内常见的呼吸道疾病；然而，结核性胸腔积液（TPE）和恶性肿瘤胸腔积液（MPE）的快速准确诊断仍然具有挑战性。尽管细胞外囊泡（EV）已被证实是有前途的疾病生物标志物来源，但对其亚群的代谢物组成及其在胸腔积液诊断中的作用知之甚少。在这里，我们进行了代谢组学和脂质组学分析，以研究通过差速超速离心从胸腔积液中获得的两个 EV 亚群的代谢物特征，即大 EV（lEV，以 20,000 × g 沉淀）和小 EV（sEV，以 110,000 × g 沉淀），并评估了结核病和恶性肿瘤之间的代谢差异。总共检测到 579 种代谢物，包括氨基酸、酰基肉碱、有机酸、类固醇、酰胺和各种脂质。结果显示，lEVs和sEVs的代谢特征既有重叠又有差异，但与胸腔积液的代谢特征有显着差异。此外，不同类型的囊泡和胸腔积液表现出独特的代谢富集。此外，与sEV相比，lEV在结核病组和恶性肿瘤组之间表现出更显着和更大的代谢变化，并且它们的差异代谢物与临床参数的相关性更密切。最后，基于全面的发现和验证工作流程，定义了胸膜 IEV 中的四个候选生物标志物，包括苯丙氨酸、亮氨酸、磷脂酰胆碱 35:0 和鞘磷脂 44:3。 该面板在区分 TPE 和 MPE 方面表现出高性能，特别是对于延迟或漏诊的患者，例如两组中受试者工作特征曲线下面积 (AUC) >0.95。我们对 EV 进行了全面的代谢谱分析，并在 lEV 和 sEV 的代谢物水平上进一步探讨了结核病和恶性肿瘤的代谢重编程，深入了解胸腔积液的机制，并确定了用于诊断 TPE 和 MPE 的新型生物标志物。