Intraepithelial Cell Population in the Allergic Nasal Mucosa

Abstract

Intraepithelial migrating cells are presumed to play an important role in nasal mucosal immunity because these are the first to come into contact with various foreign particles inhaled and deposited on the nasal surface. To elucidate nasal mucosal immunity, we carried out a quantitative study of the overall population of migrating cells and the lymphocyte subsets in the epithelial compartment of nasal mucosa in patients with house-dust nasal allergy, in patients with nonallergic rhinitis (chronic infectious rhinitis) and “normal” persons (as controls), using both light and electron microscopy in combination with an immunoperoxidase technique. Scrapings from the inferior turbinates were collected for examination of the epithelium. In order of predominance, the most numerous migrating cells were lymphocytes, followed by eosinophils, mast cells, neutrophils, and macrophages in the allergy group; in the nonallergy group neutrophils, lymphocytes, followed by macrophages and eosinophils; and in the normal group lymphocytes were the most predominant. Electron microscopic observation revealed globule leukocytes in addition to the other cells. In subjects with nasal allergy, the migrating cell population in nasal secretion differed from scrapings, in that neutrophils and eosinophils were predominant. In our study of the lymphocyte subsets, although CD8+ cells (suppressor/cytotoxic T cells) were the most numerous (followed by CD16+ [natural killer cells], CD4+ [helper/inducer T cells] and CD21+ [B cells] in that order of predominance in the epithelium), no difference was noted in number among CD4+, CD8+, and CD16+ cells in nasal secretions. On the basis of their ultrafine structure, many CD8+ cells and some CD4+ cells had the morphological appearance of activated lymphocytes. Lymphocytes, mast cells, and globule leukocytes, all of which reside in the allergic nasal epithelium, are likely to be involved in the nasal mucosal immunity.