Non-allergic rhinitis with eosinophilia syndrome is not associated with local production of specific IgE in nasal mucosa.

Non-allergic rhinitis with eosinophilia syndrome (NARES) is an eosinophilic inflammation of the nasal mucosa without evidence of an allergy or other nasal pathologies. Patients complain about perennial symptoms like nasal obstruction, rhinorrhea, itchiness and sneezing of the nose sometimes accompanied by hyposmia. The aim of the study was to better characterize NARES patients using immunoassay-biochip technology to examine serum and nasal secretion. Sera and nasal secretion of patients with NARES (perennial nasal symptoms, no evidence of acute or chronic rhinosinusitis with or without polyps, negative SX1-Screening test and/or negative skin prick test, eosinophilic cationic protein in nasal secretion >200 ng/ml) were tested by immunoassay-biochip technology (ImmunoCAP(®) ISAC, Phadia). 112 different allergen components from 51 allergen sources were tested on the chip. Furthermore, serum and nasal secretion were tested for specific IgE to Staphylococcus aureus enterotoxin TSST-1 by fluorescence-enzyme-immunoassay (UniCAP(®), Phadia). Unrecognized systemic sensitization could be ruled out by negative ISAC results in sera of all patients. Testing of nasal secretion for allergen-specific IgE by ISAC chip technology was negative as well in all cases. In one patient, a systemic sensitization to Staphylococcus aureus superantigen TSST-1 was detectable but no allergen-specific IgE to TSST-1 was measurable in nasal secretion of any patient. The results demonstrate that NARES is not associated with local allergy (entopy) nor with a local inflammation driven by Staphylococcus aureus enterotoxin TSST-1. Further studies are necessary to better understand the underlying mechanisms of NARES.