Background and objective: Combined pulmonary fibrosis and emphysema (CPFE) is characterized by upper lobe emphysema together with lower lobe fibrosis. The aim of this study was to examine whether cytokine levels in the alveolar space are associated with emphysematous changes superimposed on pulmonary fibrosis.
Methods: Consecutive patients (n = 102), diagnosed with pulmonary fibrosis were retrospectively evaluated. Cytokine levels and differential cell counts in bronchoalveolar lavage (BAL) fluid, pulmonary function, computed tomography (CT) scores and levels of serum markers were compared between patients with or without emphysema.
Results: Among the 102 patients (14 females, mean age 68 years), 38 (37%) had evidence of upper lobe emphysema on computed tomography (CT). Levels of epithelial neutrophil activating peptide 78 (ENA-78/CXCL5) and interleukin (IL)-8/CXCL8 in BAL fluid were significantly higher in patients with emphysema. Vital capacity (VC, % predicted) was greater, and ratio of forced expiratory volume in 1 s/forced vital capacity and diffusing capacity of carbon monoxide (DLCO)/alveolar volume (VA) were lower in patients with emphysema. CXCL8 and CXCL5 levels were associated with percentage or absolute numbers of neutrophils in BAL fluid. In addition, CXCL8 levels were inversely correlated with VC and DLCO/VA, and positively correlated with composite physiological index (CPI) and the extent of areas of low attenuation on CT.
Conclusions: Increased CXC chemokine levels in the airspaces may be associated with emphysematous lung changes in patients with pulmonary fibrosis.