[Diagnostic value of total serum IgE for atopy in children and adolescents]

Objective:To explore the value of total IgE in the diagnosis of atopy in children and adolescents. Methods:This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey from 2005-2006 included measurement of total and specific IgE levels and allergy questions for 6-19 year old children and adolescents. According to the results of specific IgE, participants were divided into the atopic or non- atopic group. Based on questionnaire, participants were divided into the rhinitis or non-rhinitis group. To compare the difference of total IgE between groups. The relationship between total IgE and atopy was analyzed. The value of total IgE in the diagnosis of atopy was analyzed by ROC curve. Results:①The geometric mean total IgE level in the non-atopic subjects and the atopic subjects were 24.4 kU/L and 153.1 kU/L, respectively. The difference between the two groups was statistically significant（P<0.01）. ②In logistic regression analyses, we observed the adjusted odds ratio（OR） for atopy with a 10-fold increase in total IgE level was 17.6[95%CI：14.1-22.3], statistically significant changes（P<0.01）. ③The area under the receiver operator characteristic curve（AUC） of total IgE for diagnosing atopy in the total population were 0.857. The specificity and sensitivity of total IgE at the optimal cutoff of 54.3 kU/L on the ROC curve for diagnosing atopy were76.4%, and 80.0%, respectively. At the optimal cutoff of 54.6 kU/L for diagnosing atopy in the population with rhinitis, AUC, specificity, and sensitivity were 0.888, 86.7% and 77.0%, respectively. At the optimal cutoff of 59.0 kU/L for diagnosing atopy in the population with non-rhinitis, AUC, specificity, and sensitivity were 0.841, 74.8% and 78.6%, respectively. ④The diagnostic specificity of atopy increased with total IgE, while the sensitivity decreased. Conclusion:There was a close relationship between total IgE and atopy. Total IgE level can be used to discriminates children and adolescents with and without atopy.