Protein expression shift and potential diagnostic markers through proteomics profiling of tuberculous pleurisy biopsy tissues

Objectives: Tuberculous pleurisy is a common type of tuberculosis (TB), but its diagnosis is challenging. This study aimed to profile the protein expression of this disease and identify new diagnostic makers. Methods: Biopsy tissues from patients with tuberculous pleurisy and controls were taken through thoracoscopy, and proteins were extracted for Tandem Mass Tag Mass Spectrometry. Differential protein expression was performed between patients and controls, and the identified proteins were analyzed for pathway enrichment. Selected proteins were further validated in another set of samples using a more quantitative method. Results: A total of 5101 proteins were detected and quantified in a discovery set of patients and controls. Overall protein expression was quite different between patients and controls. Most proteins were down-expressed, while a minority were overly expressed in the patient samples. At p value < 0.05 and absolute fold change >2, 295 proteins were found to be up-expressed and 608 down-expressed. The top enriched pathways included ECM-receptor interaction, complement and coagulation cascades and focal adhesion. All 19 selected candidates were validated in an independent set of patient and control samples. Conclusion: This unbiased proteomics approach not only provided unique insights into protein expression and pathways, but also discovered potential diagnostic markers for tuberculous pleurisy.