Local immune and inflammatory endotypes of the nasal mucosa in allergic and non-allergic chronic rhinitis

Background Allergic rhinitis (AR) and non-allergic rhinitis (NAR) are the main forms of chronic rhinitis with distinct pathogenesis. Endotype analysis based on nasal mucosal immune markers may facilitate precision medicine. Objective To compare inflammatory profiles and identify endotypes in AR and NAR through local immune marker detection and correlation analysis. Methods This retrospective study enrolled chronic rhinitis patients (January 2023–June 2025) divided into three groups: AR group [ARG, n=40, positive skin prick test and/or serum specific IgE (sIgE)], NAR group (NARG, n=40, negative allergy tests), and control group (CG, n=20). Primary measures: nasal eosinophil (EOS) and neutrophil (NEU) counts, sIgE and eosinophil cationic protein (ECP), Th2 cytokines, NEU-related mediators, and immune cell subsets. Results ARG showed significantly higher EOS count, sIgE, ECP, interleukin-5 (IL-5), interleukin-13 (IL-13), and EOS% than NARG and CG. NARG exhibited significantly higher NEU count, interleukin-8 (IL-8), interleukin-1β (IL-1β), and NEU% ( P < 0.01). Correlation analysis revealed moderate to strong positive correlations among Th2 markers in ARG and among NEU markers in NARG, with ECP also correlated to EOS in NARG (all P < 0.05). Conclusion AR exhibits a Th2-dominant inflammatory network involving eosinophils, IgE, and Th2 cytokines rather than eosinophils alone, while NAR displays a NEU-mediated pattern with a subset showing eosinophilic activation. Multi-marker detection in nasal secretions effectively differentiates inflammatory endotypes in chronic rhinitis. Significance & innovation This study identified a synergistic Th2 network in AR and a NEU-dominant pattern in NAR via nasal secretion analysis, providing evidence for endotype identification and precision therapy.