Association of serum eosinophilia and total immunoglobulin E concentration with the risk of allergic symptoms and allergic sensitization, respectively: A 2-year follow-up study

Abstract

OBJECTIVES: Serum eosinophil percentage (SEP), eosinophil cationic protein (ECP) concentration, and total IgE (TIgE) concentration are known to increase in patients with allergic disease; however, the relevance of these elevated markers in children with negative allergic test results remains unclear. Therefore, this 2-year follow-up study aimed to investigate whether SEP, ECP concentration, and TIgE concentration are associated with an increased risk for allergic sensitization and allergic symptoms.

METHODS: In 2012, SEP, ECP concentration, and TIgE concentration of third- and fourth-grade students from 6 elementary schools were measured. Skin prick test was performed, and the presence of allergic nasal symptoms was investigated using a questionnaire. In 2014, the same examinations were performed in the same set of students, who were then in the fifth and sixth grades, respectively, of the same schools. The cut-off value and usefulness of serologic markers (eosinophil count, ECP concentration, and TIgE concentration) were calculated using the receiver operating characteristic curve.

RESULTS: Serum eosinophil percentage (cut-off value, 3.8%) was associated with the newly developed allergic nasal symptoms (sensitivity, 77.9; specificity, 41.8). A high serum TIgE concentration (cut-off value, 17.7?IU/mL) was also associated with the risk for allergic sensitization (sensitivity, 46.3; specificity, 85.3).

CONCLUSION: SEP and TIgE concentration were associated with the development of allergic symptoms and allergic sensitization, respectively, 2 years after the first examination.