Oxidative stress (OS) is well documented in
asthma, but so far, little data has been reported in nonasthmatic patients with
Seasonal Allergic Rhinitis (SAR). The aim of this study is to investigate the degree of OS and airway
inflammation in patients with SAR, with and without concomitant
asthma (SAR+A), using breath markers in exhaled air and in Exhaled Breath Condensate (EBC). In addition, the effects of natural
allergen exposure and intranasal
steroid treatment on these markers were evaluated. Exhaled NO (eNO) and CO, combined with measurements of
8-Isoprostane (Iso-8),
Leukotriene B4 (
LTB4) and
nitrate/
nitrite in EBC, were performed in 23 patients, 11 with SAR and 12 with SAR+A, and 16 healthy subjects. Iso-8 and
LTB4 were significantly increased in both groups of patients (median values 43.6 pg/ ml and 138.4 pg/ml in SAR group; 38.9 pg/ml, and 164.6 pg/ml in SAR+A group respectively; p>0.05) compared to healthy subjects (18.6 pg/ml and 7.8 pg/ml; p<0.05).
Nitrate/
nitrite and eNO levels were elevated in both groups compared to controls, but were significantly higher in the SAR+A compared to SAR group (
nitrate/
nitrite 9 microM and 3.9 microM; p=0.025; and eNO 18.5 ppb and 12.5 ppb, respectively; p>0.05). Nasal
steroids caused significant reduction in
LTB4 and
8-isoprostane levels in both groups of patients (p<0.05), while
nitrate levels and eNO concentration were little affected by nasal treatment. OS markers were decreased at normal levels out of pollen season. Natural
allergen exposure induces OS and airway
inflammation, as assessed by measurements of markers in EBC and exhaled air, in patients with SAR who have no clinical signs of lower airway involvement. Besides, intranasal
steroid treatment may have a regulatory role in the OS.