Objective: The levels of C-reactive protein (CRP), tumor necrosis factor (TNF)-α, brain natriuretic peptide (BNP) and endothelin-1 (ET-1) were investigated to analyze the systemic inflammation in chronic obstructive pulmonary disease (COPD) patients with and without pulmonary hypertension.
Methods: From January 2006 to December 2010, 89 patients with COPD were enrolled in our hospital. There were 67 males and 22 females, with a mean age of (70 ± 7) and a mean FEV(1) of (47 ± 13)%. Pulmonary pressure was assessed by Doppler echocardiography. The levels of plasma BNP, TNF-α and ET-1 were measured by enzyme-linked immunosorbent assay kits. High-sensitivity plasma CRP level was assessed by chemiluminescent immunoassay.
Results: Forty-two patients were classified as COPD with pulmonary hypertension group and 47 patients as COPD without pulmonary hypertension group. The level of CRP [51.4 mg/L (20.1 - 92.0) mg/L], ET-1 [5.9 ng/L (3.7 - 10.4) ng/L] and BNP [303.2 ng/L (112.5 - 824.7) ng/L] in patients with pulmonary hypertension were significantly higher than in that in patients without hypertension, CRP [26.7 mg/L (11.5 - 62.9) mg/L], ET-1 [2.1 ng/L (1.3 - 4.7) ng/L] and BNP [143.7 ng/L (85.5 - 306.7) ng/L]. The level of TNF-α showed no difference between the 2 groups [8.5 ng/L (4.8 - 13.7) ng/L and 6.7 ng/L (3.2 - 10.3) ng/L], respectively. Multivariate analysis showed that PaO₂ (P < 0.05), CRP (P < 0.05) and BNP (P < 0.05) could predict pulmonary hypertension independently.
Conclusion: The level of CRP, ET-1 and BNP were related to pulmonary hypertension in COPD patients, suggesting that systemic inflammation play a role in the pathogenesis of pulmonary hypertension in COPD.