Plasma paraoxonase activity and oxidative stress and their relationship to disease severity in children with allergic rhinitis

Background: Oxidative stress may play a role in the pathophysiology of several diseases including allergic rhinitis (AR). In children with AR an antioxidant enzyme paraoxonase (PON1) has not been previously investigated. The aim of this study was to investigate plasma PON1 activity and plasma total oxidant status (TOS), which are in the form of plasma reactive oxidants, and their association with severity of disease in house-mite-sensitive children with AR. Methods: This study included 66 children with persistent AR and 40 healthy controls aged between 7 and 12 years old. Plasma PON1, TOS, and total serum immunoglobulin E (IgE) were measured. The nasal symptom scores and body mass index were evaluated at the time of blood collection. Results: Mean serum PON1 levels were significantly lower and, TOS levels were higher in the patient group than in the control group (p <= 0.001 and p <= 0.002, respectively). A significant negative correlation was observed between serum levels of PON1 and nasal symptom scores. However, serum levels of TOS were correlated with nasal symptom scores positively. There were no correlations between levels of total IgE and levels of PON1 and TOS levels. Conclusion: Plasma PON1 and TOS levels may serve as predictors of disease severity in children with AR and both of them appear to be attractive candidates for modulating inflammation in AR.