Baseline serum double-mite (D1+D2) sIgE/tIgE ratio as a predictor of early-phase response to dual-mite subcutaneous immunotherapy in allergic rhinitis

BACKGROUND: Subcutaneous immunotherapy (SCIT) for allergic rhinitis (AR) requires long-term treatment, and its phased efficacy often influences patient adherence. Identifying early biomarkers, such as serum-specific IgE to total IgE (sIgE/tIgE) ratio, may support individualized management. OBJECTIVE: To determine the predictive value of baseline double-mite (D1+D2) sIgE/tIgE ratio for phased dual-mite SCIT response in AR patients. METHODS: (D2) who received dual-mite SCIT between September 2022 and January 2023. Baseline serum tIgE and sIgE (D1+D2) were measured, and the combined sIgE/tIgE ratio was calculated. Treatment response was evaluated by reduction in visual analogue scale (VAS) scores at months 6 and 12, with the efficacy distribution compared between the two time points using the Chi-square test. Univariable and multivariable logistic regression identified predictors of achieving at least an effective response, and receiver operating characteristic (ROC) analysis was applied for sIgE/tIgE ratio when indicated. RESULTS: = 10.084, P = 0.006). At 6 months, multivariable analysis showed that both higher baseline VAS score (OR = 0.954, 95% CI: 0.929-0.980, P < 0.001) and higher sIgE/tIgE ratio (OR = 0.985, 95% CI: 0.972-0.999, P = 0.036) were independently associated with lower likelihood of achieving at least effective response. ROC analysis indicated a cutoff sIgE/tIgE ratio of 26.62% for predicting poor short-term response. At month 12, only baseline VAS score remained a significant predictor (OR = 1.038, 95% CI: 1.005-1.072, P = 0.025). CONCLUSION: SCIT efficacy progressively improves over the first year. A higher baseline sIgE (D1+D2)/tIgE ratio (>26.62%) predicts poorer short-term response, highlighting the value of objective biomarkers for early response assessment and individualized management.