A potential target for the future treatment of malignant pleural effusion: Monocyte chemoattractant protein-1 (MCP-1)

<b>Background and Aim:</b> Malignant pleural effusion (MPE) is a common clinical problem. Management options are mainly pleurodesis and drainage, and have remained unchanged for years. Novel therapies that target the molecules responsible for fluid formation are needed to reduce the need for invasive procedures. The aim of this study is to investigate the potential role of MCP-1 in the development of MPE in patients with metastatic pleural malignancies. <b>Methods:</b> Pleural effusion samples (8-10 ml) were collected from 100 patients who were divided into three groups: Group 1 (MPE, n = 56), Group 2 (benign exudate, n = 27) and Group 3 (transudate, n = 17). The collected effusions were promptly centrifuged at 4°C, and the supernatants were stored at -80°C. MCP-1 levels were determined by ELISA kit (USCN, Wuhan). <b>Results:</b> Median MCP-1 levels were found to be significantly different between the three groups (Group 1: 1303 pg/ml, Group 2: 926 pg/ml, Group 3: 211 pg/ml) (<i>p</i> < 0.001). MCP-1 levels were markedly higher but similar in Group 1 and Group 2, as compared to Group 3. When patients from Group 1 and Group 2 were combined, a positive correlation was observed between pleural fluid MCP-1 and LDH levels (r = 0.38; <i>p</i> = 0.001). Additionally, MCP-1 levels were observed to increase significantly as the volume of pleural fluid increased (<i>p</i> = 0.007). <b>Conclusion:</b> MCP-1 levels were found to be similarly high in both Group 1 (MPE) and Group 2 (Benign exudate), indicating that inflammation accompanying the tumor could play a role in the formation of pleural effusion. This suggests that the development of biological therapies targeting MCP-1 could be a promising approach in the future management of MPE.