Immunohistological characteristics of nasal polyps. A comparison with healthy mucosa and chronic sinusitis.

Immunohistological investigations were performed on a series of samples from 37 patients with nasal polyps, 22 with chronic sinusitis, and 15 controls with healthy nasal and sinusal mucosa. Mean numbers of plasma- and mast cells were not different in the various groups. Immunoglobulin isotypes were always predominantly IgA and IgM; IgE were scarce. Deposited immune complexes were always absent. A statistically significant difference, however, was observed in the number of eosinophils within the mucosa. Patients with nasal polyps had up to ten times more eosinophils per surface unit than patients with sinusitis or healthy mucosa.