Comparison of Selected Markers of Local and Systemic inflammation in Patients with Community-Acquired Pneumonia and Pneumonia Co-existing with Lung Cancer

Background: The aim of the study was to compare markers of local and systemic inflammation in patients with community-acquired pneumonia (CAP) and pneumonia co-existing with lung cancer. Material and methods: We enrolled 17 patients with CAP (Group 1), 14 patients with pneumonia co-existing with lungcancer (Group 2), 24 patients with lung cancer (Group 3) and 16 healthy individuals (Group 4, the control group). We evaluated the concentrations of hydrogen peroxide (H₂O₂), vascular endothelial growth factor (VEGF) and tumour necrosis factor-alpha (TNF-α) in exhaled breath condensate (EBC) and serum concentrations of VEGF and TNF-α. Results: We found significantly higher EBC concentrations of VEGF and TNF-α in patients with pneumonia co-existing with lung cancer than in CAP patients (317.83 ± 77.78 vs. 30.20 ±6.56 and 1.98 ± 0.13 vs. 0.31 ± 0.05, respectively). Although the EBC concentration of H₂O₂ in patients with pneumonia co-existing with lung cancer was higher than that in CAP patients (0.96 ± 0.16 vs. 0.66 ± 0.09), the difference was not significant (p > 0.05). In CAP patients, however, we observed significantly higher serum concentrations of both cytokines compared to patients with pneumonia co-existing with lung cancer (VEGF: 1112.62 ± 244.38 vs. 392.9 ± 78.2; TNF-a: 2.6 ± 0.48 vs. 1.6 ± 0.2). Conclusions: Patients with pneumonia co-existing with lung cancer show a distinct tendency towards local oxidative stress and a significantly increased local response compared to CAP patients. On the other hand, systemic inflammation in patients with pneumonia co-existing with lung cancer is markedly reduced compared to patients with CAP