Diagnostic role of complete blood count in pleural effusions

Abstract

Pleural effusion (PE) can be seen during the course and treatment of many malignant or benign diseases. Congestive heart failure and pneumonia are the most common causes of benign pleural effusion (BPE), while lung and breast cancer are the most common causes of malignant pleural effusion (MPE). MPE indicates that the disease is extensive or advanced and the average survival is 4-12 months. In this study, we aimed to investigate the changes in complete blood count parameters in patients with benign and malignant PE. Patients who underwent thoracentesis and pleural fluid analysis between January 1, 2015 and December 1, 2020 were included in the study. Demographic characteristics, pathological diagnoses, pleural fluid cell analysis, blood parameters of the patients were recorded. The patients were divided into two groups according to their MPE and BPE detection status. Complete blood count parameters, Systemic Inflammatory Index (SII), Platelet / Lymphocyte Ratio (PLR), Monosin / Lymphocyte Ratio (MLR), Eosinophil / Lymphocyte Ratio (ELR) and Neutrophil / Lymphocyte Ratio (NLR) values were found in both groups and were recorded and compared. 240 patients with PE and meeting the study criteria were included in the study. There were 154 (64.17%) patients with BPE and 86 (35.83%) patients with MPE. In patients with MPE, WBC (103 / mL) 10.22 (2.32-27.50) (p = 0.001), Neutrophil (103 / UL) 8 (0.48-24.25) (p <0.001), Monocyte (103 / UL) 0.7 (0-1.9) (p = 0.002) were detected. In addition, SII 1868.54 (139.88-16862.63) (p = 0.001), NLR 6.68 (0.38-92.91) (p = 0.001), MLR 0.58 (0-4.46) (p = 0.038) were detected. All these values were statistically higher than the patients with BPE. SII, MLR and NLR values are cheap and easily applicable parameters that can help in the differentiation of malignant and benign pleural effusion, in predicting the prognosis of patients with MPE and in treatment planning.