Correlation of C-reactive protein with disease severity in CT diagnosed emphysema

Background and objective:   Recent studies suggest that CRP levels are related to airflow obstruction. However, limited data exist on the relevance of CRP levels in individuals with or without emphysema. The aim of this study was to assess the relationship between the extent of emphysema, COPD severity and serum CRP levels.
Methods:   Lung function tests and high-sensitivity CRP were examined in 651 males with stable disease who underwent CT screening for lung cancer. CRP levels were examined cross-sectionally in individuals with various degrees of emphysema and in those without emphysema.
Results:   Emphysema was detected in 179 (34.7%) of 516 current smokers. Airflow obstruction was observed in 47 (28.8%) of 163 smokers with mild emphysema, in eight (57.1%) of 14 smokers with moderate emphysema, and in two of two individuals with severe emphysema. CRP levels were not higher in individuals with mild or moderate emphysema compared with individuals without emphysema. Among 98 individuals with airflow obstruction (19.0% of the 516 current smokers), there was a modest correlation between CRP levels and FEV₁%.
Conclusions:   The severity of COPD varied in individuals with similar degrees of emphysema. CRP levels were not significantly higher in individuals with mild or moderate emphysema compared with individuals without emphysema but CRP levels were modestly correlated with FEV₁% among individuals with airflow obstruction.