Abstract
Introduction: Exhaled biomarkers may indicate disease processes in idiopathic pulmonary fibrosis (IPF). We performed a PRISMA-compliant systematic review to investigate whether such markers discriminate between patients with IPF and healthy controls or correlate with lung function.
Methods: Database searches were performed using the terms (Pulmonary fibrosis OR Lung Diseases, interstitial OR Fibrosing Alveolitis OR Diffuse Parenchymal Lung Disease OR Usual Interstitial Pneumonia) AND (Breath tests OR Volatile Organic Compounds OR Metabolomics OR Breath analysis OR Breath biomarkers OR Breathomics OR exhaled breath). Study selection was limited to adults with a diagnosis of IPF as per international guidelines.
Results: 1014 studies were screened, 53 underwent full text review and 15 fulfilled selection criteria. The mean number of IPF patients included was 19 (range 6-40). 20 individual biomarkers discriminated between IPF and healthy controls, and four correlated with lung function. Metanalysis of three studies indicated alveolar nitric oxide levels were higher in IPF (8.5±5.5 ppb) than controls (4.4±2.2 ppb). Measurements of oxidative stress, such as hydrogen peroxide and 8-isoprostane were also found to discriminate between IPF and controls. Two breathomic studies, one using exhaled breath condensate and the other using volatile organic compounds have isolated discriminative compounds using mass spectrometry. One, p-cymene, correlated with lung function.
Conclusions: Evidence suggests alveolar nitric oxide is higher in patients with IPF, however in general studies were limited by small sample size. Further breathomic work may identify biomarkers with diagnostic and prognostic potential.
Methods: Database searches were performed using the terms (Pulmonary fibrosis OR Lung Diseases, interstitial OR Fibrosing Alveolitis OR Diffuse Parenchymal Lung Disease OR Usual Interstitial Pneumonia) AND (Breath tests OR Volatile Organic Compounds OR Metabolomics OR Breath analysis OR Breath biomarkers OR Breathomics OR exhaled breath). Study selection was limited to adults with a diagnosis of IPF as per international guidelines.
Results: 1014 studies were screened, 53 underwent full text review and 15 fulfilled selection criteria. The mean number of IPF patients included was 19 (range 6-40). 20 individual biomarkers discriminated between IPF and healthy controls, and four correlated with lung function. Metanalysis of three studies indicated alveolar nitric oxide levels were higher in IPF (8.5±5.5 ppb) than controls (4.4±2.2 ppb). Measurements of oxidative stress, such as hydrogen peroxide and 8-isoprostane were also found to discriminate between IPF and controls. Two breathomic studies, one using exhaled breath condensate and the other using volatile organic compounds have isolated discriminative compounds using mass spectrometry. One, p-cymene, correlated with lung function.
Conclusions: Evidence suggests alveolar nitric oxide is higher in patients with IPF, however in general studies were limited by small sample size. Further breathomic work may identify biomarkers with diagnostic and prognostic potential.
| Original language | English |
|---|---|
| Article number | PA2921 |
| Journal | European Respiratory Journal |
| Volume | 52 |
| Issue number | Suppl 62 |
| DOIs | |
| Publication status | Published (in print/issue) - 15 Sept 2018 |