Changes in eotaxin-2 and periostin levels in patients with bronchial asthma according to their smoking status: a cross-sectional study

Background Smoking influences the nature of airway inflammation in patients with bronchial asthma though synthesis of certain cytokines. Patterns of bronchial asthma are differentiated clinically, functionally, and regarding inflammatory biomarkers. Aim The research aimed to study the clinical, functional, sputum cytological differences, and serum eotaxin-2 and periostin levels in asthmatic patients regarding smoking status. Patients and methods The research was a cross-sectional study. The collection of cases began in August 2018 and ended in January 2020 at the Chest Department, Assiut University Hospital. We studied 117 asthmatic patients who were classified regarding their smoking status (45 nonsmokers, 42 smokers, and 30 former smokers) for serum eotaxin-2 and periostin by enzyme-linked immunosorbent assay. The effects of smoking were analyzed on inflammatory cells including eosinophilic and neutrophilic percentages in sputum and serum eotaxin-2 and periostin levels. Results Smokers with asthma had worse clinical and functional outcomes. Asthmatic smokers had mainly neutrophilic phenotype. Serum eotaxin-2 level was higher in smokers compared with nonsmokers and former smokers. However, serum periostin level was higher in nonsmokers compared with smokers and former smokers. Serum eotaxin-2 had a positive correlation with smoking index and eosinophilic and neutrophilic count in sputum, whereas serum periostin was correlated negatively with smoking index and positively with eosinophilic count. Conclusion Asthmatic smokers had worse clinical and functional outcomes with increased neutrophils in the sputum. The inflammatory biomarkers seen in smokers with asthma showed low serum periostin and increased serum eotaxin-2 levels.