GM-CSF, IL-8, IL-1R, TNF-ALPHA-R, AND HLA-DR IN NASAL EPITHELIAL-CELLS IN ALLERGIC RHINITIS

Epithelial cells potentially contribute to airways inflammation by ant igen presentation and the production of proinflammatory cytokines. Thi s study investigated the immunocytochemical localization of interleuki n-8 (IL-8), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 receptor (IL-1R Type I), tumor necrosis factor-alpha re ceptor (TNF-alpha R; 55kD), and human leukocyte antigen-DR (HLA-DR) on epithelial cells obtained by nasal brushing from 10 patients with all ergic rhinitis in season and 15 healthy, nonallergic subjects. Six of the 15 nonallergic asymtomatic subjects had macroscopic evidence of na sal mucosal inflammation, and their brushings contained more than 10% neutrophils (''sub-clinical inflammation''). In normal control subject s, 8 +/- 7.5% of epithelial cells stained for HLA-DR, approximately on e quarter stained for IL-8 and GM-CSF, and about one third stained pos itive for IL-1R and TNF-alpha R. The findings in subjects with allergi c rhinitis in season and with subclinical neutrophilia were similar, a nd the numbers of cells staining for HLA-DR, IL-8, GM-CSF, IL-1R, and TNF-alpha R were significantly greater than in normal control subjects . In nonallergic subjects, GM-CSF and IL-8 expression correlated signi ficantly with neutrophil content; HLA-DR expression correlated with bo th neutrophil and lymphocyte content. These findings further support t he conclusion that epithelial cells can contribute to inflammatory pro cesses in the nasal mucosa. The findings emphasize the need to identif y asymptomatic nasal mucosal inflammation in studies of the nasal muco sa.