In Situ Analysis of the Immune Microenvironment of the Adenoid in Children with and without Secretory Otitis Media

Abstract

Using monoclonal antibodies and immunohistochemistry, we compared adenoid tissue from 35 children with or without secretory otitis media. Numerous cells infiltrating the reticular crypt epithelium expressed HLA-DR, as did <10% of the epithelial cells. Of the antigen-presenting cells, CD1a+ dendritic cells showed intraindividual and interindividual variations; CD68+ macrophages and CD22+ B cells were uniformly distributed. The relative frequencies of CD4+ and CD8+ cells were 6.6 ± 2.0 versus 2.3 ± 1.2 (p < .001) in the reticular crypt epithelium and 18 ± 4.5 versus 1.5 ± 0.9 (p < .001) in the germinal centers. The IL-2 receptor was expressed on <0.1% of CD3+ T cells. Over 90% of intraepithelial CD3+ T cells were of the CD45RO+ memory phenotype. The proliferation marker Ki67 was almost exclusively found in the germinal centers. That the analyzed parameters showed a similar pattern in both clinical groups suggests that the presence of secretory otitis media may not correlate to specific alterations in the immune microenvironment of the adenoid.