Increased Serum Periostin Levels and Eosinophils in Nasal Polyps Are Associated with the Preventive Effect of Endoscopic Sinus Surgery for Asthma Exacerbations in Chronic Rhinosinusitis Patients
<b><i>Background:</i></b> Eosinophilic nasal polyps (NPs) are associated with the presence of asthma in chronic rhinosinusitis (CRS) patients. Serum periostin has been considered a relevant biomarker for unified airway diseases. <b><i>Objective:</i></b> To determine the utility of biomarkers including serum periostin that reflects reduction of exacerbations of comorbid asthma in CRS patients. <b><i>Methods:</i></b> We prospectively recruited 56 CRS patients who were subjected to undergo endoscopic sinus surgery (ESS) (20 with asthma) between October 2015 and December 2017 and followed them for 1 year after ESS. Blood eosinophil count, serum periostin, and fractional nitric oxide (FeNO) were measured at enrollment. How these type 2-driven biomarkers reflect comorbid asthma was determined using receiver operating characteristic (ROC) analysis. The frequency of asthma exacerbations during 1 year was counted both before and after ESS. Associations between preoperative biomarkers including eosinophils in NPs and asthma exacerbations were evaluated. <b><i>Results:</i></b> Blood eosinophil count, FeNO, and serum periostin levels were significantly higher in CRS patients with asthma than in those without (<i>p</i> < 0.01 for all) and discriminated comorbid asthma among CRS patients (<i>p</i> < 0.05; AUC > 0.80 for all). The increased preoperative serum periostin correlated with lower absolute number of postoperative exacerbations (ρ = −0.49, <i>p</i> = 0.03) and its relative reduction after ESS (ρ = 0.53, <i>p</i> = 0.03) in asthmatic patients. Increased eosinophils in NPs were also associated with reduced asthma exacerbations. <b><i>Conclusion:</i></b> Preoperative increased serum periostin and eosinophils in NPs are associated with the preventive effect of ESS for asthma exacerbations in CRS patients comorbid with asthma.