PURPOSE: To determine if pleural fluid levels of pro- and anti-inflammatory cytokines differentiate non-complicated (NC-PPE) from complicated parapneumonic pleural effusions (C-PPE) and correlate with pleural fluid biochemical parameters.
METHODS: Pleural fluid of 60 patients with NC-PPE (n= 31) or C-PPE (n= 29) was assessed by thoracentesis and samples were assayed for biochemical (pH, LDH and glucose) and pro- (IL-1b, IL-8 and VEGF) and anti-inflammatory (IL-1ra, IL-10, TNF sRI and TNF sRII) cytokines analysis. Statistics: Student t-test (p< 0.05) and linear regression.
RESULTS: Values comparing NC-PPE x C-PPE (median; NS= not significant): Biochemical: pH (7.7 x 7.5; NS); LDH (419 x 2335 IU; p< 0.001) and Glucose (102 x 21 mg%; p< 0.001).Pro-inflammatory Cytokines: IL-1b (3.9 x 279 pg/ml; p< 0.001); IL-8 (348 x 1805 pg/ml; p= 0.003) and VEGF (355 x 1356 pg/ml; p= 0.003). Anti-inflammatory Cytokines: IL-1ra (717 x 3094; p< 0.001); IL-10 (172 x 199 pg/ml; NS); TNF sRI (9,134 x 10,114 pg/ml; p= 0.042) and TNF sRII (16,525 x 20,109 pg/ml; p=0.042).
CONCLUSION: Pleural fluid levels of pro-inflammatory cytokines IL-1b, IL-8 and VEGF, and anti-inflammatory cytokines IL-1ra, TNF sRI and TNF sRII were significantly higher in complicated in comparison to non-complicated PPE. In NC-PPE positive correlations were found between LDH levels and IL-8 (R= 0.67; p= 0.01), and glucose levels with IL-10 (R= 0.75; p< 0.001) and TNF sRI (R= 0.70; p= 0.003). None of the cytokines correlated with pleural pH levels.
CLINICAL IMPLICATIONS: The more intense inflammatory reaction in C-PPE supports the fact that C-PPE shall be treated more aggressively than NC-PPE. Pleural fluid glucose levels may be used as a reference to determine degree of pleural inflammation and guide treatment options.
DISCLOSURE: Evaldo Marchi, No Financial Disclosure Information; No Product/Research Disclosure Information