Significance of total serum IgE in children with lower respiratory infections due to respiratory syncytial virus

ABSTRACT

PURPOSE: Respiratory syncytial virus (RSV) is known to induce Th2 immune response with increased IgE production. We investigated serum IgE levels in RSV bronchiolitis/pneumonia (RSV-LRI) in relation to disease severity. METHODS: One hundred seven children admitted with RSV-LRI were enrolled. The patients were divided into 2 groups according to serum IgE levels: the high IgE (n=39, more than 2 standard deviations from the mean levels for age-matched controls) and low IgE groups (n=68). We investigated if there were any differences in clinical and laboratory findings, and recurrence of wheezing between the 2 groups. The difference in IgE levels between severe (severity score≥3) and nonsevere groups was also studied. RESULTS: More frequent and prolonged fever was observed in the high IgE group than in the low IgE group (P<0.05). Patients showing severe symptoms or respiratory difficulties were more frequently seen in the high IgE group (P=0.01). There was no difference in parental allergy and atopic sensitization. The nearly same findings were observed in reanalysis of data from patients with the first RSV-LRI, but recurrence of wheezing was significantly higher in the high IgE group than in the low IgE group (P=0.04). Patients with high IgE levels were more frequently seen in severe patients than in nonsevere patients (P=0.01). CONCLUSION: Our study showed that children who presented with high serum IgE levels during RSV infections had more severe symptoms compared to those with low IgE levels. It suggests that measurement of total serum IgE levels might be helpful in evaluating disease severity and recurrent wheezing in children admitted with RSV-LRI.