ABSTRACT
INTRODUCTION: Oxidative stress (OS) plays a crucial role in the pathogenesis of inflammatory lung diseases. OBJECTIVES: (i) We determined whether acute bronchiolitis (AB) caused by respiratory syncytial virus (RSV) induced OS; (ii) assessed whether OS biomarkers correlated with the severity of RSV-AB; and (iii) studied whether the levels of interleukins are associated with OS biomarkers. METHODS: We performed an observational study by comparing healthy infants (Group 1) with RSV-AB infants, classified as Group 2 (pulse oximetry (SpO2 ) >93%), and Group 3 (SpO2 ≤ 92%), which needed oxygen therapy. Blood samples were collected to determine the levels of lipid peroxidation (LPO) products (LPO), total glutathione (TG), oxidised glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), interleukins (ILs) IL-10, IL-6, IL-8, interferon-gamma (IFNγ), tumour necrosis factor-alpha (TNFα) and macrophage inflammatory proteins (MIP α and MIP ß). RESULTS: Forty-six RSV-AB infants (47% needed oxygen therapy) and 27 healthy infants were included. The GSH/GSSG ratio was lower in RSV-AB infants than in Group 1 (P<0.001). GSSG and GPx were significantly higher in Group 3. GSSG predicted the need for oxygen therapy with an optimal cut-off point of 15 µM/g for haemoglobin. The GSH/GSSG ratio negatively correlated with IL-6 (P: 0.014), IL-8 (P: 0.014) and IL-10 (P: 0.033). Group 3 exhibited a direct correlation between GPx and IL-10 levels (P: 0.024) and between LPO and MIP ß (P: 0.003). CONCLUSIONS: RSV induced OS in AB. An increase in GSSG correlated with the disease severity in the infants. OS may contribute to the pathogenesis of RSV-AB.
Subject(s)
Biomarkers/metabolism , Bronchiolitis/complications , Oxidative Stress/physiology , Respiratory Syncytial Virus Infections/blood , Acute Disease , Bronchiolitis/metabolism , Bronchiolitis/therapy , Bronchiolitis/virology , Female , Glutathione/metabolism , Humans , Infant , Interferon-gamma/metabolism , Interleukin-10/metabolism , Interleukins/metabolism , Lipid Peroxidation , Male , Oximetry/methods , Oxygen Inhalation Therapy/methods , Respiratory Syncytial Virus Infections/physiopathology , Respiratory Syncytial Virus Infections/therapy , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/isolation & purification , Severity of Illness Index , Tumor Necrosis Factor-alpha/metabolismABSTRACT
UNLABELLED: This cross-sectional study was performed to examine the prevalence of hypovitaminosis D in infants with acute bronchiolitis compared with control subjects and to evaluate the relationship between serum 25-hydroxyvitamin D (25(OH) D) and the severity of bronchiolitis. Serum 25(OH) D levels were measured by radioimmunoassay in 48 infants with acute bronchiolitis (2.5 ± 2.0 months) and in 30 healthy infants (3.2 ± 2.3 months). 25(OH) D levels (ng/ml) in children with acute bronchiolitis were significantly lower than in the control group (median 29.9 ng/ml (interquartile range (IQR) 21.4-37.5) versus median 38.2 ng/ml ((IQR 26.1-48.1), p = 0.022), mainly in infants with moderate-severe bronchiolitis (median 29.8 ng/ml, IQR 19.2-35.9). The prevalence of hypovitaminosis D was remarkably greater among infants with bronchiolitis than in control subjects (52.1 versus 26.6%). A significant inverse correlation was found between serum 25-hydroxyvitamin D levels and disease severity (rho = -0.457, p < 0.001). CONCLUSION: The prevalence of hypovitaminosis D is high in Spanish infants with bronchiolitis. The severity of acute bronchiolitis increases with a decline in serum 25 (OH) D level.
