Abstract: Objective To investigate the levels of eosinophils (EOS) in peripheral blood and tissues of children with adenoid hypertrophy, and its correlation with allergic factors. Methods A total of 112 children underwent adenoidectomy in the department of otorhinolaryngology, head and neck surgery of Tianjin First Center Hospital from October 2017 to July 2018 were selected as the study objects. These children were divided into two study groups: adenoid hypertrophy only (AH,n=62) group and adenoid hypertrophy with allergic rhinitis (AH+AR, n=50) group. The number of EOS in tissue sections stained with hematoxylin-eosin (HE) was observed under high power microscope. The percentage of EOS in peripheral blood was detected. In addition, the serum specific IgE detection and visual analogue scales (VAS) were performed in all children,and the differences of the levels of EOS in tissues and peripheral blood were analyzed. The receiver operating characteristic(ROC) curve was drawn to analyze the diagnostic value of the EOS levels in tissues and peripheral blood for allergic factors in children with AH+AR. Results The EOS level was significantly higher in AH + AR group than that in AH group (P＜ 0.05). There were no significant differences in EOS levels between different levels of allergen (P＞0.05). The EOS level in peripheral blood was significantly higher in patients with severe allergic rhinitis than that of patients with mild allergic rhinitis (P＜0.05). There were no significant differences in the EOS levels between severe and moderate rhinitis, moderate and mild rhinitis (P＞0.05). In tissues, the more severe the symptoms of allergic rhinitis are, the higher the level of EOS is(P＜0.05). According to the ROC curve, the area under the curve (AUC): peripheral blood was 0.791 (95%CI: 0.705-0.878，P＜0.001), the cut-off value was 2.60%, and the sensitivity was 70.0%, the specificity was 74.2%; and in tissue AUC was0.843 (95%CI: 0.765-0.920, P<0.001), the cut-off value was 3/10 sections, and the sensitivity was 76.0% and the specificity was 80.6%. Conclusion The EOS levels in adenoid tissue and peripheral blood are increased in children with positive serum specific IgE, suggesting that there are allergic factors are in the etiology of AH. The EOS level in tissues is more important for the differential diagnosis of allergic factors.

Key words: hypersensitivity, eosinophils, tissues, peripheral blood, adenoid hypertrophy