A European Respiratory Society technical standard: exhaled biomarkers in lung disease

TLDR

Breath tests measure fractions of nitric oxide, volatile organic compounds, exhaled breath condensate variables, and other metrics, with established standards for FeNO and EBC but none for VOCs and particles. This document aims to provide technical standards and recommendations for sample collection and analytic approaches, while highlighting future research priorities in exhaled biomarker research. The Task Force reviewed published breath test methodology and, through consensus, developed recommendations for standardised sampling, analysis, and reporting. The report evaluates recent technological advances in EBC and FeNO and presents consensus recommendations for standardised sampling, analysis, and reporting to enable comparable results. The report clarifies that it does not offer clinical guidance on disease diagnosis or management and was authored by invited clinicians and researchers with expertise in exhaled biomarkers.

Abstract

Breath tests cover the fraction of nitric oxide in expired gas (FeNO), volatile organic compounds (VOCs), variables in exhaled breath condensate (EBC) and other measurements. For EBC and for FeNO, official recommendations for standardised procedures are more than 10 years old and there is none for exhaled VOCs and particles. The aim of this document is to provide technical standards and recommendations for sample collection and analytic approaches and to highlight future research priorities in the field. For EBC and FeNO, new developments and advances in technology have been evaluated in the current document. This report is not intended to provide clinical guidance on disease diagnosis and management.Clinicians and researchers with expertise in exhaled biomarkers were invited to participate. Published studies regarding methodology of breath tests were selected, discussed and evaluated in a consensus-based manner by the Task Force members.Recommendations for standardisation of sampling, analysing and reporting of data and suggestions for research to cover gaps in the evidence have been created and summarised.Application of breath biomarker measurement in a standardised manner will provide comparable results, thereby facilitating the potential use of these biomarkers in clinical practice.