DIFFERENCES IN CELLULAR INFILTRATES IN THE ADENOID OF ALLERGIC CHILDREN COMPARED WITH AGE-MATCHED AND GENDER-MATCHED CONTROLS

Background Allergic sensitization of the airways occurs in the mucosa of the shock organ, or in the lymphatic stations draining these struct ures. The lymphatic structure closest to the nasal mucosa is the adeno id. Objectives The objective of this study was to find evidence for ou r hypothesis that allergic sensitization can occur in the adenoid. Of special interest, in this context are cell types involved in antigen-a llergen presentation (e.g. Langerhans cells) and effector cells of all ergic disease. Methods In this study cellular infiltrates in adenoids of 16 allergic patients and 16 age- and gender-matched controls were e valuated. The number of cells positive for CD1a, CD4, CD8, CD-68, chym ase, tryptase, IgE, MBP and cells positive for interleukin (IL)-4 were determined using immunohistochemical staining techniques. The epithel ium, follicles and the interfollicular spaces were evaluated separatel y. Results When comparing the two groups a significant increase in cel ls positive for CD1a was found in interfollicular spaces of the allerg ic group (P = 0.008). CD1a(+) cells in the follicular space and eosino phils in the interfollicular space showed a trend to be more numerous in the allergic group (P = 0.02 and P = 0.05, respectively). The other cell types investigated did not show significant differences between the groups. Conclusions The results of this study show for the first t ime that cells involved in allergic sensitization and allergic disease differ in the adenoid of allergic children compared with controls. Th ese findings support our hypothesis that allergic sensitization takes place in the adenoid. Furthermore, this study confirms that CD1a(+) (L angerhans) cells are involved in allergic disease.