Analysis of Blood-based Biomarkers of Asthma

This is a cross-sectional study in patients with asthma and healthy controls in which we will analyze markers of inflammation in blood and in induced sputum for the purpose of identifying molecular markers of specific asthma phenotypes. Our specific interest in demonstrating that periostin levels are higher than normal in blood. We already have solid preliminary data to support this hypothesis, and our goal here is to replicate preliminary findings and extend them by examining further the characteristics of the asthma subgroup with elevated periostin levels. In this regard, we propose detailed phenotyping of the asthmatic subjects and the healthy controls, including measures in induced sputum, exhaled air and detailed physiologic measures including measures of airflow, lung volumes, and methacholine responsiveness. In earlier work we have found that periostin is a marker of Th-2 driven asthma, and we will use the data collected here to further explore this possibility. The biospecimens collected here will also allow us to expand existing plasma, DNA, RNA, and sputum samples in the UCSF Airway tissue bank, so that we can continue to build this resource for future research questions.