Allergic rhinitis is increasing steadily in recent days, but there are no specific markers which can predict the risk of allergic sensitization individually. Serum eosinophil, eosinophil cationic protein (ECP), and total IgE (TIgE) are known to increase in patients with allergic disease. However, the clinical significance of these serologic results are not well evaluated. We aimed to investigate whether serum eosinophil, ECP, and TIgE are associated with increased risk of allergic sensitization and allergic symptoms on the basis of 2 years follow-up study.
In 2012, serum eosinophil, ECP, and TIgE were measured in 3rd and 4th grade students of 5 elementary schools. Skin prick test was performed with 26 aeroallergens commonly found in Korea. The presence of allergic symptoms during past 12 months was checked using questionnaire. In 2014, same study was performed in 5th and 6th grade same students attending same schools. The cut off value and usefulness of serologic markers (serum eosinophil, ECP, and TIgE) were calculated using the receiver operating characteristic curve.
Serum eosinophil fraction (Cut off value 3.8%) was associated with the newly developed allergic symptoms (sensitivity 41.8, specificity 77.9 ; Odd ratio 2.424 , p = 0.006). Higher serum total IgE (cut off value 17.7 IU/ml) was also associated with the risk of allergic sensitization (sensitivity 85.3, specificity 46.0; Odd Ratio 4.848 , p<0.001).
Serum eosinophilia and total IgE were associated with the future risk of allergic symptoms and allergic sensitization, respectively. Further study is needed to elucidate the predictability of serum eosinophil and TIgE to consider the future risk of allergy.