Serum Periostin as a Biomarker for Comorbid Chronic Rhinosinusitis in Patients with Asthma

Rationale: Periostin is a matricellular protein that is involved in the pathophysiology of allergic rhinitis, chronic rhinosinusitis, and asthma. Associations of serum periostin with systemic and airway eosinophilic inflammation and comorbid chronic rhinosinusitis in patients with asthma have been demonstrated. Although serum periostin is positioned as a marker of helper T cell 2 immune responses, its implication regarding the presence of comorbid upper airway diseases in patients with asthma remains unclear. Objectives: To investigate the utility of serum periostin as a diagnostic biomarker for upper airway disease in patients with asthma. Methods: Weprospectively enrolled 65 patients with stable asthma, 20 without upper airway disease, 22 with rhinitis, and 23 with chronic rhinosinusitis (13 with nasal polyps, 10 without). Serum periostin, eotaxin, total IgE, fractional exhaled nitric oxide, and blood and sputum eosinophil levels were measured and compared between upper airway disease subtypes. We evaluated the utility of each biomarker in detecting upper airway disease, associations among the biomarkers, and severity of upper airway disease as measured by the Lund-Mackay score for sinus computed tomography. Results: Serum periostin levels were higher in patients with asthma who had chronic rhinosinusitis (109.6647.4 ng/ml) than in those without upper airway disease (83.2622.9 ng/ml) (P = 0.04). Serum periostin levels in patients with asthma who had chronic rhinosinusitis and nasal polyps were significantly higher (130.0646.6ng/ml) than in those without nasal polyps (87.9637.7 ng/ml) (P = 0.001). Serum periostin levels were not associated with the presence or the severity of rhinitis. In contrast, receiver operating characteristic curve analyses showed moderate diagnostic accuracy for detecting chronic rhinosinusitis (areaunder the curve, 0.71; P = 0.01) andhigh accuracy for chronic rhinosinusitiswith nasal polyps (area under the curve, 0.86; P = 0.0002). When we compared patients with asthma who had comorbid chronic rhinosinusitis and nasal polyps with patients with asthma without these comorbidities, we found serum periostin to be the sole biomarker among those tested for detecting the presence of nasal polyps. Serum periostin was also the sole biomarker that significantly correlated with Lund-Mackay score in patients with chronic rhinosinusitis (r = 0.44; P = 0.04). Conclusions: Serum periostin is useful for detecting chronic rhinosinusitis with nasal polyps and predicting radiological chronic rhinosinusitis severity in patients with asthma.