A characteristic protein in nasal discharge differentiating non-allergic chronic rhinosinusitis from allergic rhinitis.

To differentiate non-allergic chronic rhinosinusitis (vasomotor rhinitis) from allergic rhinitis, a characteristic protein in the nasal discharge was studied. The subjects consisted of 10 patients with perennial allergic rhinitis to house dust, 10 patients without perennial rhinitis without antigen (clinically defined as non-allergic chronic rhinosinusitis) and 5 normal volunteers without nasal disease as a control group. The total protein in the nasal discharge was determined by Lowry's method and analysis of the protein components was made by SDS-PAGE. It was found that the nasal discharge obtained from the case with perennial allergic rhinitis contained a high concentration of albumin (25.9 micrograms/ml) and a characteristic protein band with an estimated molecular weight of 26 kilo-Daltons (kD) on a SDS-PAGE, in a concentration of 15.8 micrograms/ml. In contrast, the nasal discharge from non-allergic chronic rhinosonusitis patients contained a lower concentration of albumin (12.9 micrograms/ml) than that of the allergic rhinitis patients, and the concentration of the characteristic protein 26 kD was only 2.3 micrograms/ml. The 26 kD protein was considered to originate from the nasal glands, since its secretion could be provoked by stimulation of the nasal glands of the normal volunteers with a 1% pilocarpine spray. The low concentration of albumin and the characteristic protein 26 kD in the nasal discharge thus appeared to differentiate patients with non-allergic chronic rhinosinusitis from those with perennial allergic rhinitis.