Novel Perspectives in the Detection of Oral and Nasal Oxidative Stress and Inflammation in Pediatric United Airway Diseases

<jats:p> United airway disease (UAD) concept proposed that asthma and rhinitis are both different clinical manifestation of a single inflammatory process. The aim of this study is to assess in upper and lower airways the level of inflammation and oxidative stress and to investigate the relationship between biomarkers in persistent allergic rhinitis (PER) and in concomitant asthma with PER. By a cross-sectional study we measured oral and nasal (FE <jats:sub>NO</jats:sub> ) and oral and nasal EBC 8-isoprostane, LTB <jats:sub>4</jats:sub> and PGE in children with PER (n=14) and with PER and concomitant intermittent asthma (IA; n=25), mild persistent asthma (mA; n=28), moderate persistent asthma (MA; n=13) and in Healthy Controls (HCs; n=13). Oral and nasal FE <jats:sub>NO</jats:sub> concentrations were increased in children with PER, IA, mA and MA when compared with HCs. Nasal 8-isoprostane was higher in EBC of children with PER and asthma than in HCs. Oral and nasal LTB <jats:sub>4</jats:sub> were higher in EBC of children with PER and mA than in HCs. Oral and nasal PGE <jats:sub>2</jats:sub> concentrations were higher in EBC of children with PER than in HCs. Positive correlations between oral and nasal biomarkers were found in IA for LTB4 and PGE2, in mA for FE <jats:sub>NO</jats:sub> , 8-isoprostane, LTB and PGE <jats:sub>2</jats:sub> , and in MA for PGE <jats:sub>2</jats:sub> . No correlations were observed in children with PER and HCs. Our results suggest that non-invasive markers of inflammation and oxidative stress might be useful to study the relationships between oral and nasal compartments in allergic children with PER and concomitant asthma with the aim of defining the UAD. </jats:p>