Advances in exhaled breath condensate markers for severe asthma management: a systematic review

Background: Severe asthma is a chronic respiratory disease posing challenges for clinicians and patients, increasing health-care costs and patients’ poor quality of life. Advances in precision medicine have introduced novel approaches to managing severe asthma, including breathomics, a promising field using exhaled breath analysis to identify disease biomarkers. Among these techniques, exhaled breath condensate (EBC) analysis has emerged as a potential noninvasive tool for monitoring airway inflammation and disease progression. Methods: A systematic literature review was conducted to identify EBC biomarkers for monitoring severe asthma, searching across PubMed, Cochrane, Google Scholar, MEDLINE, ISRCTN, EMBASE and Web of Science. Results: Twenty-three studies were included in the review. Key markers identified were 8-isoprostane, hydrogen peroxide (H₂O₂), nitric oxide (NO), and eicosanoids. Among these, 8-isoprostane was the most widely studied biomarker in severe asthma, while H₂O₂ seems to be most closely linked to assessing asthma control. Conclusions: To the best of our knowledge, this is the first systematic review focusing on EBC biomarkers in severe asthma. Breath analysis represents a promising noninvasive approach to evaluate airway inflammation, identify early signs of poorly controlled asthma and monitor treatment response. Further research is needed to validate these biomarkers for clinical application. Protocol registration: uk/prospero with identifier CRD42023406669 https://www.crd.york.ac.