Evaluation of nasal fluid β-defensin 2 levels in children with allergic rhinitis

Abstract

Aim: Knowledge about the role of the innate immune system in the pathogenesis of allergic diseases has been expanding in recent years. Defensins are antimicrobial peptides that are components of the innate immune system. Defensins have strong efficacy against bacterial, viral, and fungal infections. Moreover, they have regulatory functions in many physiologic processes such as antitumoral immunity, chemotaxis, inflammation, and wound healing. In this study, we aimed to investigate β-defensin 2 levels in the nasal fluids of children with allergic rhinitis. Material and Methods: Study and control groups consisted of 28 patients with newly diagnosed allergic rhinitis who were not taking any medication, and 23 healthy children. Skin prick tests were performed on patients with allergic rhinitis and disease severity was assessed using the total symptom score. Nasal fluid samples were obtained using a modified polyurethane sponge absorption method from patients and control subjects. Nasal fluid β-defensin 2 levels were determined using an enzyme-linked immunosorbent assay (ELISA). Results: The median value of nasal fluid β-defensin 2 levels were 173.8 pg/mL (interquartile range; 54.8-205.9 pg/mL) in allergic rhinitis group and 241.6 pg/mL (163.5-315.2 pg/mL) in the control group. There was a statistically significant difference between the two groups (p=0.01). Moreover, nasal fluid β-defensin 2 levels showed a significant negative correlation with total symptom scores (rho=-0.78, p<0.001). Conclusions: Children with allergic rhinitis have reduced nasal fluid β-defensin 2 levels compared with controls, and β-defensin 2 levels were negatively correlated with disease severity. A more definite understanding of the roles of defensins and other antimicrobial peptides in allergic inflammation can open up new horizons in the management and treatment of these common diseases.