Fibrocytes as Key Mediators of Type 2 Inflammation in Asian Chronic Rhinosinusitis With Nasal Polyps.

CRSwNP exhibits distinct inflammatory patterns across populations, with type 2 (T2) inflammation predominating in Western but less frequent in Asian patients. Recent single-cell studies have highlighted fibroblast subsets contributing to T2 inflammation; however, the role of fibrocytes remains unclear. In this study, nasal polyp tissues from 10 adult patients meeting EPOS/EUFOREA 2023 T2 criteria were analyzed using high-parameter spectral flow cytometry (Sony ID7000) to assess IL-4, IL-5, and IL-13 expression across epithelial and immune cell types. Fibrocytes demonstrated the highest IL-4 and IL-13 expression, comparable to T cells, whereas IL-5 expression showed no significant difference among cell types. These findings suggest that fibrocytes may be a previously underrecognized T2 cytokine-producing population in CRSwNP, and that fibrocytes, together with T cells, may be key drivers of type 2 inflammation and represent potential therapeutic targets in Asian patients with CRSwNP.