Adult asthma biomarkers.

Abstract

PURPOSE OF REVIEW: A variety of novel asthma treatments have been developed based

on phenotypes, and the clinical trial results show promising responses. This

review summarizes the current knowledge of biomarkers for the determination of

asthma phenotypes. RECENT FINDINGS: Eosinophilic inflammation is the most focused

phenotype because most novel asthma treatments have targeted T-helper type 2

(Th2) pathway. Fractional-exhaled nitric oxide (FeNO) is a new method that

represents an eosinophilic airway inflammation with a significant correlation

with sputum eosinophilia and asthma severity instead of sputum eosinophil count

that easily influenced by corticosteroid therapy. However, some reports indicated

the discordance between treatment response or adjustment and FeNO levels. Serum

periostin is a strong serum biomarker for eosinophilic airway inflammation and an

indicator of Th2-targeted therapy (such as lebrikizumab or omalizumab) and

airflow limitation. YKL-40 is associated with asthma severity and airway

remodeling. In addition, genetic and metabolomic approaches have been made to

determine asthma phenotypes and severity. SUMMARY: Biomarkers such as FeNO and

serum periostin represent eosinophilic airway inflammation, together with

eosinophil-derived neurotoxin and osteopontin (OPN) needed more replication

studies. Periostin, YKL-40, OPN and some metabolites (choline, arginine, acetone

and protectin D1) are related to asthma severity and airflow limitation.