Clara Cell Protein in Nasal Fluid and its Genotypes in Children with Allergic Rhinitis

Background: Allergic rhinitis (AR) results from interactions between a large number of pro- and anti-inflammatory mediators. Clara cell secretory protein maps to an atopy-associated region of chromosome 11 and has been ascribed an anti-inflammatory function. To date the relationship of this protein and its genotypes with persistent AR has not been extensively studied. Objective: To explore the association of Clara cell protein in nasal fluid and A38G genotypes with persistent AR and to investigate the correlation of this protein level with the disease severity. Methods: Nasal fluid Clara cell protein was analyzed in 15 patients with AR, 11 with nonallergic rhinitis (NAR), 29 with AR associated with bronchial asthma (ARBA), 12 with AR associated with atopic dermatitis (ARAD) and 23 healthy controls. The A38G single nucleotide polymorphism was also analyzed in all patients and controls. Results: The nasal fluid levels of Clara cell protein were significantly lower in the AR and ARBA groups compared to the controls (p=0.001 and 0.018 respectively) and were neg-atively correlated (r=-0.523, p 0.001) with total nasal symptom score in the AR patients. Also, the incidence of 38AA genotype was significantly higher in the AR, NAR, and ARBA groups compared to the controls (p=0.009, 0.034, and 0.001 respec-tively). Conclusion: We suggest that reduction in anti-inflamma-tory activity by Clara cell protein may contribute to the pathogenesis and severity of persistent allergic rhinitis in children.