Total serum immunoglobulin E (IgE) as an effective predictor for identifying allergic asthma in childhood asthma.

Allergic asthma accounts for the majority of childhood asthma and is characterized by elevated total serum immunoglobulin E (tIgE). However, whether tIgE can predict allergic asthma in childhood asthma remains unclear. The purpose of this study was to identify the potential of tIgE for predicting allergic asthma in childhood asthma and provide a reliable reference value. Clinical characteristics and the level of tIgE from children with asthma in 2008 (n = 280) and 2018 (n = 479) were retrospectively analyzed. Receiver operating characteristic (ROC) curves were generated to determine the optimal cutoff points and predictive values of tIgE for diagnosing allergic asthma in childhood asthma in 2008 and 2018, and the diagnosis efficiency of tIgE was validated in 491 children with asthma of 2019. The level of tIgE was significantly lower in 2018 than that in 2008. Receiver operating characteristic curves showed cutoff values of tIgE were 142.50 IU/mL (area under the curve [AUC] = 0.864) and 96.25 IU/mL (AUC = 0.835) for diagnosing allergic asthma in 2008 and 2018, respectively. The level of tIgE from children with asthma in 2019 was similar to that in 2018 but was significantly lower than that in 2008. We further used the cutoff value of tIgE = 96.25 IU/mL to validate the diagnosis efficiency in children with asthma of 2019 and found that the diagnostic accuracy, sensitivity, specificity of allergic asthma, and the Youden index reached 76.78%, 76.10%, 78.03%, and 0.540, respectively. The tIgE value is an effective predictor for diagnosing allergic asthma in childhood asthma, with tIgE = 96.25 IU/mL being the recommended limit.