The clinical implication of serum cyclophilin A in patients with chronic obstructive pulmonary disease

Background Cyclophilin A (CyPA) is a secreted molecule that is regulated by inflammatory stimuli. Although inflammation has an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD), little is known regarding the relationship between serum CyPA and COPD. Methods Ninety-three COPD patients with acute exacerbation were enrolled in the study and were reassessed during the convalescence phase. Eighty-eight controls were matched for age, gender, body mass index, smoking index and comorbidity. The basic clinical information and pulmonary function of all participants were collected. Serum levels of CyPA and other inflammation indexes were further measured. Results Serum CyPA was significantly increased in convalescent COPD patients compared to healthy controls, and further elevated in COPD patients with acute exacerbation. Serum CyPA positively correlated with serum interleukin-6, matrix metalloproteinase-9 and high-sensitivity C-reactive protein in both the exacerbation and convalescence phases of COPD. Furthermore, it negatively correlated with percent value of forced expiratory volume in 1 second (FEV1%) predicted and FEV1/forced vital capacity in convalescent COPD patients. Conclusion These results suggest that serum CyPA can be used as a potential inflammatory biomarker for COPD and assessment of serum CyPA may reflect the severity of inflammation in COPD.