Can biomarkers give a clue in acute bronchiolitis? A study of HIF-1, VEGF, Ang-1, and Ang-2 levels

Background: Long-term effects of bronchiolitis have been argued to may trigger inflammation and angiogenesis by hypoxia via Hypoxia Induced Factor 1 (HIF-1), Vascular Endothelial Growth Factor (VEGF), Angiopoietin-1 (Ang-1), and Angiopoietin-2 (Ang-2) pathway leading to chronic changes. Objective: Our aim in this study is to understand if HIF-1, VEGF, Ang-1, and Ang-2 levels increase after the initial bronchiolitis attack and trigger changes in airways. We also aim to see if there is any correlation between the levels of these biomarkers and bronchiolitis severity. Methods: Patients who were admitted to the Pediatric Emergency Department and diagnosed as acute bronchiolitis were included and severity of bronchiolitis was evaluated by the Respiratory Distress Assessment Instrument score. Levels of HIF, VEGF, Ang-1, and Ang-2 levels in bronchiolitis patients were compared with healthy children. Results: Thirty-three patients were included in the study group. HIF-1, VEGF, Ang-1, and Ang-2 levels were not significantly different between the study and control groups with a 95% confidence interval. When mild and moderate-severe bronchiolitis groups were compared, biomarker levels were not significantly different between groups. Conclusions: Our results suggest that acute temporary hypoxia and inflammation in bronchiolitis probably do not trigger angiogenetic changes. It is possible that instead of viruses directly causing chronic changes via inflammatory pathways, allergic sensitization itself may increase the risk of wheezing in acute bronchiolitis.