Relationship between sputum periostin level and inflammatory asthma phenotypes in Egyptian patients

Asthma is a common chronic inflammatory air way disease which poses a high disease burden worldwide. Asthma is a heterogenous disease with various phenotypes and endotypes. Refractory asthma requires new and personalized approaches to manage it effectively. Periostin is a promising biomarker that may help in predicting severity, prognosis and could be a therapeutic target. We aimed in this study to investigate periostin levels in the sputum of asthmatic Egyptian patients of inflammatory phenotypes and its relation to asthma severity.

This study included 96 adult asthmatic patients; 48 patients with mild-to-moderate bronchial asthma, 48 patients with severe bronchial asthma according to ATS criteria and 10 healthy controls. All participants were subjected to full history taking and clinical examination; pulmonary function tests; skin prick test; induced-sputum analysis for inflammatory cells and periostin.

Sputum periostin concentrations were significantly higher in patients with asthma than in controls. Sputum periostin is strongly correlated with age and sputum TLC and inversely correlated with FEV1. It is correlated with sputum neutrophil count and sputum eosinophil percentage. Best cut off value for sputum periostin is >528.25 ng/ml to differentiate between mild-to-moderate and severe asthma.

Sputum periostin levels provide a satisfying diagnostic accuracy in severe asthmatic with persistent airflow limitation than mild-to-moderate asthmatic adults. There is a modest positive correlation between sputum periostin and sputum eosinophilia.