IMMUNOHISTOLOGY OF THE NASAL-MUCOSA IN SEASONAL ALLERGIC RHINITIS - INCREASES IN ACTIVATED EOSINOPHILS AND EPITHELIAL MAST-CELLS

The immunohistology of the nasal mucosa was examined in 13 grass pollen-sensitive patients and in seven normal nonatopic control subjects before and during the pollen season. Cryostat sections (6-mu-m) of biopsy specimens from the inferior turbinate were immunostained with the alkaline-phosphatase antialkaline-phosphatase method and a panel of monoclonal antibodies. Mast cell subtypes were measured with a double sequential immunostaining method. Within the submucosa, seasonal increases in total (MBP+, p < 0.01) and "activated" (EG2+, p < 0.01) eosinophils were observed for the patients, which were significant when these counts were compared with counts for those of control subjects (MBP+ p < 0.01; EG2+ p < 0.001). Within the nasal epithelium, seasonal increases in total (p < 0.05) and "activated" (p < 0.02) eosinophils were also observed. Mast cell counts revealed seasonal increases in tryptase-only positive mast cell (MC(T)) (p < 0.02) but not chymase plus tryptase-positive mast cells (MC(TC)) within the epithelium that were significant when counts were compared with those of control subjects (p < 0.03). No significant changes were observed within the submucosa or epithelium for total leukocytes (CD45+ cells) or T-lymphocytes (CD3+, CD4+, CD8+, and CD 25+ cells) for either group. Similarly, no significant changes were observed for neutrophils (antielastase), macrophages (CD68+), nor HLA-DR+ cells. In the subjects with rhinitis, seasonal submucosal CD3+ counts correlated with MBP+ eosinophils (r = 0.56; p < 0.05) and MC(T)s (r = 0.65; p < 0.02). Similarly, seasonal epithelial EG2+ eosinophil counts correlated with MC(T)s (r = 0.56; p < 0.05). The results indicate that seasonal allergic rhinitis is associated with local accumulation of "activated" eosinophils and the epithelial migration of MC(T)s but not MC(TC)s during natural grass-pollen exposure.