Local IgE is a superior biomarker than serum IgE for nasal type 2 inflammation in house dust mites sensitized allergic rhinitis.

Allergic rhinitis (AR), an immunoglobulin E (IgE)-mediated inflammatory disease, is frequently associated with house dust mites (HDMs), particularly Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f). While serum allergen-specific IgE (sIgE) is widely used, the diagnostic value of local sIgE and its interplay with systemic IgE and nasal cytokines remains unclear. This study evaluated local sIgE performance, nasal cytokine profiles, and nonlinear local-serum sIgE dynamics for AR patients. This prospective study enrolled 60 HDM-sensitized AR patients and 143 healthy controls from February 2023 to September 2024. Serum and local Der p/Der f sIgE and total IgE were quantified; and nasal cytokines were analyzed by Luminex. Logistic regression, ROC analysis, and Spearman correlation assessed diagnostic performance and associations.Restricted cubic spline (RCS) modeling explored nonlinear local-serum sIgE relationships. AR patients exhibited elevated local Der p and Der f sIgE logistic regression confirmed their associations with AR, supported by strong diagnostic accuracy. Local sIgE demonstrated stronger correlations with type 2 cytokines (IL-4, IL-5, CCL5, CCL11) than serum sIgE. RCS analysis identified inflection points for Der p and Der f, revealing threshold-dependent nonlinear dynamics between local and serum sIgE. Local sIgE demonstrates high diagnostic accuracy for HDM-sensitized AR and better reflects local Th2-driven inflammation. The nonlinear local-serum sIgE relationship advocates dual-compartment profiling, advancing precision diagnostics in AR.