Periostin in allergic rhinitis: from pathogenic mediator to predictive biomarker and therapeutic target.

Allergic rhinitis (AR) is a common disease around the world, mediated by type 2 immune responses, and some patients don't respond well to current standard treatments. This shows AR isn't a single type of disease but a complex syndrome caused by different internal body mechanisms. Periostin is a key matrix protein sitting downstream of the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathways, connecting type 2 immune responses and nasal mucosal tissue remodeling. This article explains periostin's many roles in AR: it breaks down the epithelial barrier, makes eosinophils gather, and causes fibrosis, and these things form a never-ending "inflammation-repair" vicious cycle. In clinical use, periostin levels in different biological samples matter-they relate to how severe the disease is and show how patients respond to glucocorticoids and biologics. Targeting periostin directly might offer new ways to help with hard-to-treat tissue remodeling. Based on these findings, we suggest a way to classify AR using periostin levels, which aims to guide personalized treatment in the future and help AR diagnosis and therapy become true precision medicine.