Aims: To elucidate the associations between respiratory syncytial virus (RSV) infection and reactive oxygen stress and between wheezing illness and reactive oxygen stress.
Method: Subjects were 61 children aged ≤4 years who were hospitalized with RSV infection(42 patient; RS group), bronchial asthma without RSV (8 patients; BA group), and acute bronchitis and pharyngitis(11 patient; Br group).Levels of blood nitric oxide (NOx), high mobility group box-1 (HMGB-1), thioredoxin,and eosinophil-derived neurotoxin and urine 8-hydroxydeoxyguanosine (8-OHdG),NOx,biopyrrin,and 8-isoprostanes were measured on admission day(acute phase),on hospital days 3–5(recovery phase), and 1–2 weeks after discharge(late phase).This study was approved by the Ethics Committees of National Hospital Organization Fukuyama Medical Center, and the parents of all subjects provided written informed consentin accordance with the Declaration of Helsinki.
Results: HMGB-1 was higher in the RS and BA groups during the recovery and late phases than during the acute phase,and higher during the late phase in the RS and BA groups than in the Br group(RS group: recovery/acute 1.19, late/acute 1.37; BA group: 1.20,1.47; Br group:1.12,1.14,respectively).Urine 8-OHdG was higher in the RS group than in the BA and Br groups during the recovery and late phases (RS group: recovery/acute 4.03, late/acute 1.92; BA group: 1.51,0.61; Br group:1.77,0.93, respectively). No significant differences were found in other biomarkers.
Conclusion: In young children with acute respiratory tract illness with wheeze,reactive oxygen stress was high during the recovery and late phases. Lower respiratory tract inflammation might persist after the acute phase leading to bronchial hyperresponsiveness.