Serum eosinophil cationic protein level in Chinese subjects with nonallergic and local allergic rhinitis and its relation to the severity of disease

Background: Nonallergic rhinitis (NAR) is a common disease, and local allergic rhinitis (LAR) is a newly described entity that is called entopy in recent years. However, the etiology and incidence of NAR and LAR are uncertain. This study evaluates the incidence of LAR in Chinese subjects and serum eosinophil cationic protein (ECP) levels in patients with NAR and LAR and its relationship with symptom scores. Methods: Positive skin-prick tests (SPT), nasal allergen provocation testing (NAPT) to Dermatophagoides farinae (DF), serum Phadiatop tests, and symptom score evaluations were performed in 147 patients with nonatopic persistent rhinitis. LAR was diagnosed by positive NAPT to DF results. The serum ECP level was measured using the UniCAP100 automated system by enzyme-linked immunosorbent assay (Pharmacia Diagnostics, Uppsala, Sweden). Results: Twelve patients were diagnosed with LAR, and 135 patients were diagnosed with NAR. There was no statistical difference of the visual analog scale scores between the two groups. Serum ECP was significantly increased in the patients with NAR. Serum ECP in the LAR group showed no difference compared with the NAR group or the controls. In the NAR group, nasal obstruction, rhinorrhea, and total scores had close and statistically significant relationships with serum ECP level. Conclusion: The present study provides the first evidence that LAR exists in Chinese subjects. This study also suggests that eosinophils and ECP take part in the pathogenesis of NAR. A local examination for ECP and specific IgE in nasal lavage fluid or secretions in patients with LAR should be performed in a future study.