Inflammatory biomarkers in chronic obstructive pulmonary disease

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is a multicomponent disease. There is a need for biological markers for better evaluation of patients with COPD. Objective: To test the hypothesis that elevated levels of inflammatory biomarkers fibrinogen, C-reactive protein (CRP) and leukocyte count (WBC) in individuals with stable COPD are associated with an increased risk of exacerbation. Patients and methods: Ninety-eight COPD patients diagnosed and classified as COPD and 30 age and gender matched healthy subjects with normal pulmonary function were observed. Patient follow-up was performed to evaluate the strength of the associations between inflammatory biomarker levels and future outcome. Results: Inflammatory biomarkers increase with exacerbation compared to the remission state, mean WBC, CRP and fibrinogen at 12.212 × 109/L, 39.462 mg/L and 5.09 g/L in exacerbation respectively compared to 7.877 × 109/L, 4.142 mg/L and 2.299 g/L in remission with P values <0.001, <0.001 and <0.004, respectively. Statistically significant correlation was noticed between the levels of fibrinogen and the % predicted FEV1 (r = 0.209, P = 0.038) however CRP and WBC did not correlate with % predicted FEV1 (r = −0.031, P = 0.765) for CRP, and that for WBC (r = 0.125, P = 0.221). Conclusion: Elevated levels of CRP, fibrinogen and leukocyte count in individuals with COPD were associated with increased exacerbation risk. Fibrinogen in particular has emerged as a potentially useful biomarker and requires further investigation.

Keywords

• Inflammatory biomarkers
• COPD
• CRP
• Fibrinogen