A study of the proteomic expression in patients with complicated parapneumonic pleural effusion

Introduction: The present study aimed to investigate the differences in the proteomic expression between uncomplicated parapneumonic pleural effusion (UPPE) and complicated parapneumonic pleural effusion (CPPE). Material and methods: There were 10 patients with UPPE and 10 patients with CPPE. These patients were combined due to the complication of pleural effusion and further divided into group A and group B. An LC-MS analysis was conducted with the extraction of high-abundance proteins, and proteins with 1.5-fold or higher difference multiples were identified as differential proteins. Then, gene ontology (GO) and KEGG analyses were conducted on the differential proteins between the groups. Results: Compared with the UPPE group, there were 38 upregulated proteins and 29 downregulated proteins in the CPPE group. The GO analysis revealed that the CPPE group had enhanced expressions in monosaccharide biosynthesis, glucose catabolism, fructose-6-phosphate glycolysis, glucose-6-phosphate glycolysis, and NADH regeneration as well as reduced expressions in fibrinogen complexes, protein polymerization, and coagulation. Moreover, the KEGG analysis showed that the CPPE group had enhanced expressions in amino acid synthesis, the HIF-1 signalling pathway, and glycolysis/glyco-isogenesis and decreased expressions in platelet activation and complement activation. Conclusions: In pleural effusion in patients with CPPE, there are enhanced expressions of proteins concerning glucose and amino acid metabolism, NADH regeneration, and HIF-1 signalling pathways together with decreased expressions of proteins concerning protein polymerization, blood coagulation, platelet activation, and complement activation.