Sputum periostin in relation to different asthma phenotypes: 9

Abstract

Maged Refaat, MD FAAAAI, Eman Elsayed, MD, and Hoda Elsayed, MD; Department of Allergy and Clinical immunology, Ain Shams university, Cairo, Egypt. RATIONALE: Asthma is a heterogeneous disease, and appropriate classification of asthma phenotypes can improve our understanding of asthma pathogenesis, therapeutics and targeted management. Although Serum Periostin has been investigated as a novel biomarker in asthma, few studies have been concerned with the sputum periostin levels in correlation with asthma phenotypes. So, we aimed to evaluate the sputum periostin levels in different clinical and cellular asthma phenotypes. METHODS: 96 patients with asthma (48 with mild to moderate asthma and 48 with severe asthma) and ten healthy controls were examined. sputum periostin, inflammatory cell counts in induced sputum and pulmonary function tests were performed. RESULTS: 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 withFEV1. 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 betweenmild tomoderate and severe asthma, with Area under the curve 0.921 (95%CI 0.86 0.97)sensitivity 95.8%, specificity is 77.1%, positive predictive value (PPV) is 80.7% and negative predictive value (NPV) is 94.9%. CONCLUSIONS: sputum periostin levels provide a satisfying diagnostic accuracy in severe asthmatic with persistent airflow limitation than mild to moderate asthmatic adults.