Diagnostic value of total serum IgE levels combined with eosinophils in allergic rhinitis at different ages

Objective To evaluate the diagnostic value of total serum immunoglobulin E （IgE） levels， eosinophil （EOS） count and percentage in the diagnosis of allergic rhinitis （AR）， and to construct a diagnostic model for preliminary diagnosis of AR by combining total serum IgE and EOS. Methods Clinical data of 305 AR patients and 256 non-AR patients admitted to Department of Otolaryngology at the First Affiliated Hospital of Chongqing Medical University from April 2023 to April 2024 were retrospectively analyzed. The general information， total serum IgE level， EOS count and percentage were compared between two groups. Binary logistic regression analysis was used to screen for suitable indicators to construct the predictive model， and the receiver operating characteristic （ROC） curve was plotted. The area under the ROC curve （AUC） was used to determine the predictive value of this model. Clinical data from 216 patients with and without AR admitted to Department of Otolaryngology at the First Affiliated Hospital of Chongqing Medical University from June 2019 to June 2022 were collected for external validation. Stratification analysis was performed according to age [adolescent group （≤ 18 years old）， youth group （19-45 years old）， middle-aged group （46-60 years old）， and elderly group （&gt; 60 years old）]， respectively. Results The percentage of EOS and total serum IgE level were the influencing factors of AR in the overall and all age groups. The combined diagnostic model for all patients was： Logit <i>P =</i> -4.174+6.856EOS count+ 0.048total serum IgE. Diagnostic model in adolescent group was： Logit <i>P =</i> -4.472+0.637EOS percentage+0.034total serum IgE； youth group： Logit <i>P =</i> -4.491+0.372EOS percentage+0.068total serum IgE； middle-aged group： Logit <i>P = </i>-4.759+5.768EOS count+ 0.062total serum IgE； elderly group： Logit <i>P = </i>-4.888+0.855EOS percentage+0.028total serum IgE， respectively. Hosmer-Lemeshow goodness-of-fit test， ROC curve analysis and external validation all indicated that this model had high diagnostic value. Conclusion The combination of total serum IgE levels and EOS count demonstrates good diagnostic value for AR in different age groups， which can be used to guide preliminary diagnosis of AR.