A Comparative Evaluation of the Vascular Endothelial Growth Factor Levels in the Patients with Exudative and Transudative Pleural Effusion abstract
Pleural effusion (PE) representing extreme fluid detention in the pleural cavity, is a common medical issue that divided into "transudates" and "exudates". Recognizing the type of PEs is an essential intervention to prevent unnecessary and invasive diagnostic procedures that cause health care costs and complications. Increased vascular permeability is one of the main mechanisms in the production of PE which a multi-functional cytokine named vascular endothelial growth factor (VEGF) has a significant role in its pathogenesis. This study aimed to compare the pleural levels of VEGF in transudative and exudative PE besides the other pleural markers, trying to accurize the classification of pleural fluid.Materials and Methods: In the current cross-sectional study, 80 patients with PE via the ability of tapping, were evaluated in a purposive manner in Ghaem Hospital, Mashhad, Iran, during 2013. The participants with coagulation disorder (international normalized ratio (INR) more than 2 and platelets less than 100,000 per microliter), or patients with malignancy undergoing chemotherapy with anti-VEGF drugs were excluded. Before the thoracentesis, all cases signed informed consent. Then the patients were divided into 4 groups as transudative (n=15), parapneumonic (n=15), tuberculosis (n=25), and malignant PE (n=25) based on the results of biochemical markers analysis of pleural fluid, pleural biopsy, medical history, and clinical signs. At last, the pleural VEGF level was measured by enzyme-linked immunosorbent assays (ELISA) after heparinizing, centrifuging, and freezing at -20°C. This study was approved by the Mashhad University of Medical Science Ethics Committee. Data were analyzed using Chi-square, t-test, ANOVA, and Pearson tests in IBM SPSS v.15 and significance was set at P=0.05.Findings: A mean age of 55.34 ± 18.53 years was assigned for 80 eligible participants (including 63.75% male). Pleural VEGF levels were not correlated with age, gender, and positive cytology rate (P=0.402, P=0.109, and P=0.146, respectively). There were significant differences in pleural VEGF between transudative and exudative effusions (r=-9196.78, P<0.001), and also between benign and malignant effusions (r=-8994.61, P=0.014). Additionally, the pleural VEGF was significantly higher in malignant comparing tuberculosis effusions (P=0.005). In this study, VEGF higher than 7309 pg/dl had a 64% sensitivity and 82% specificity for the diagnosis of malignancy.Conclusion: This survey confirms that VEGF may be assumed as an important factor in the differential diagnosis of PEs, especially malignant effusion. Moreover, it can be used for discriminating different lymphocytic exudative PE. Nevertheless, this evidence should be further assessed in larger investigations to determine VEGF efficacy in the diagnosis of effusions