Eosinophil cationic protein in mucosal biopsies from patients with allergy and otitis media with effusion

Nine patients with persistent middle ear effusion and allergy confirmed by skin testing were evaluated for eosinophils by histochemical staining of middle ear mucosal biopsy specimens for eosinophil cationic protein. The study was designed to determine whether eosinophils were present in the middle ear mucosa of these patients and whether the elevated levels of eosinophil cationic protein reported in effusion from patients with chronic otitis media with effusion and allergy might originate within the mucosa itself. Seven of nine patients with otitis media with effusion had eosinophil cationic protein containing eosinophils (12 to 15 per high-power field) and degranulated eosinophil cationic protein material in the stroma of their mucosal biopsy specimens. Positive and negative biopsy findings correlated directly with respective high and low effusion levels of eosinophil cationic protein (p = 0.03), reflecting an intrinsic immune-mediated process occurring within the middle ear mucosa.