IN-SITU ANALYSIS OF THE IMMUNE MICROENVIRONMENT OF THE ADENOID IN CHILDREN WITH AND WITHOUT SECRETORY OTITIS-MEDIA

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.