Residual Pleural Thickening Is Related to Vascular Endothelial Growth Factor Levels in Parapneumonic Pleural Effusions

Abstract

Background: Many patients with pneumonia develop pleural effusions. Pleural fluid vascular endothelial growth factor (VEGF) levels are known to be elevated in complicated parapneumonic effusion and seem to play a major role in the fibrotic process in the pleura. Objectives: To test whether VEGF levels in pleural effusions of infectious origin correlate with the residual pleural thickening. Methods: VEGF levels were measured in the pleural fluid of 45 patients with pleural effusion of infectious origin. Patients were reassessed 3 months after hospital discharge and residual pleural thickening (RPT) was recorded using a simple chest radiograph. Results: Pleural fluid VEGF was higher in empyemas compared to simple parapneumonic and complicated parapneumonic effusions. RPT was higher in patients with empyemas compared to simple parapneumonic effusions. Patients with RPT >2 mm had higher pleural fluid LDH and pleural fluid to serum LDH ratio, lower glucose and pH and higher VEGF levels. However, patients with RPT ≧10 mm differed only in pleural fluid VEGF levels. Pleural fluid VEGF levels correlated to RPT and to pleural fluid pH. VEGF presented moderate performance for the prediction of RPT 3 months after hospital discharge. Its performance was comparable to that of pleural fluid glucose and pH for the development of a radiologically significant RPT >2 mm, whereas it was the only statistically significant predictor of a clinically significant RPT ≧10 mm. Conclusion: VEGF levels are elevated in complicated parapneumonic effusions and empyemas compared to simple parapneumonic effusions and are a significant predictor for the development of clinically significant RPT.

Clinical Importance of Angiogenic Cytokines, Fibrinolytic Activity and Effusion Size in Parapneumonic Effusions

“…A recent study showed that RPT was related to the pleural fluid VEGF levels in patients with PPE [31]. In agreement with the previous reports [10], [31], our study indicated that the increased angiogenic activity in the pleural fluid might contribute to subsequent development of pleural fibrosis in PPE. Furthermore, our results signified the possible role of VEGF-related impaired fibrinolytic activity in the formation of RPT in PPE and that the patients with RPT had a significantly lower FVC than did those without.…”

“…A previous in?vivo study demonstrated that angiogenesis was required in the development of pleural fibrosis [10], [11]. A recent study showed that RPT was related to the pleural fluid VEGF levels in patients with PPE [31]. In agreement with the previous reports [10], [31], our study indicated that the increased angiogenic activity in the pleural fluid might contribute to subsequent development of pleural fibrosis in PPE.…”

Endocan and the respiratory system: a review

“…For instance, it has been reported that TGF-β and VEGF levels are elevated in complicated parapneumonic effusions and empyemas, with the latter exhibiting a predictive value for the development of residual pleural thickening 76–78. As both growth factors1,30 induce endocan’s expression we postulate that endocan correlates with parapneumonic effusions as well, but this hypothesis may warrant further investigation.…”

Prognostic value of C‐reactive protein in parapneumonic effusions

“…In addition, measurement of pH pf is highly dependent on the method of sample collection, and evaluation of pH pf is problematic in patients with systemic acidosis or Proteus infections 1,8 . On the other hand, clinical features including purulent pleural fluid, increased severity of pneumonia, temperature ≥38°C and delayed resolution after diagnosis (>15 days) have shown to be associated with RPT 3,9 …”