Objective: In this study, CD23, low affinity immunoglobulinE receptor, expression in the adenoid tissue was investigatedimmunohistochemically and evaluated with regardto upper respiratory tract infection complaints and allergy.Methods: This retrospective study was performed by theselection of 100 patients aged 2-13 years who underwentadenoidectomy/adenotonsillectomy and in whom the adenoidtissue pathological studies were reported as “lymphoidhyperplasia and chronic infection” were evaluated.Immunohistochemical evaluation of CD23 expressionwas scored semiquantitatively between 0-3 in the tissuesamples.Results: The mean age in the study group was 70.7months; 46% were female; 30% of patients had adenoidectomyonly. Following the operation, the infection frequencydecreased in 91% of patients, whereas allergysymptoms were unchanged in 84%. CD23 expressionwas found significantly lower in patients who had allergicmanifestations, namely urticaria (p=0.041), drug sensitivity(p=0.035) and pollen allergy (p=0.037).Conclusion: A significantly reduced CD23 expressionwas found in adenoidal tissue in patients with allergicsymptoms. These results can be assessed as an underlyingmechanism for the recurrence of respiratory tractcomplaints in these children, despite adenoidectomy. JClin Exp Invest 2013; 4 (1): 1-7Key words: CD23 expression, adenoid tissue, atopy