D1.122 - Hydrogen peroxide in exhaled breath condensate as a marker for monitoring biologic treatment response in severe asthmatic patients

Monitoring airway inflammation in severe asthma patients on biologics requires objective biomarkers, as assessing optimal control based mainly on symptoms and lung function has limitations. In this context, we investigated hydrogen peroxide (H₂O₂) in exhaled breath condensate (EBC) as a potential marker of airway inflammation.

This monocenter prospective study involved a cohort of 16 severe asthma patients treated with monoclonal antibodies and a control group of 16 healthy volunteers. Hydrogen peroxide (H2O2) levels were measured using the Inflammacheck® device developed by Exhalation Technology, at baseline for all individuals and over two weeks for the asthmatic patients.

Symptoms were defined as high vs. low-controlled based on asthma control questionnaires ACT and ACQ6. Low-control was defined as ACT≤19 and/or ACQ6≥1 and high-control: ACT>19 and/or ACQ6<1. WhitneyU test (p≤0.05) was used to compare H2O2 of high-controlled severe asthmatics and healthy controls.

Among the 16 severe asthma patients, no significant differences in exhaled hydrogen peroxide (H₂O₂) levels were observed at baseline and after two weeks. Low-controlled patients (n=5) showed exhaled H₂O₂ level significantly higher (0.96 μM [IQR: 0.8-1.4]) compared to the high-controlled patients (n=11; median[IQR]: 0.5[0.1-0.6]μM) (p=0.002). These latter, exhibited slightly elevated H₂O₂ concentrations compared to healthy controls (n=16; median[IQR]: 0.4[0.1-0.6]) (p=0.05; p=0.01. Based on ACT, ACQ6, respectively).

These preliminary findings suggest that H2O2 is associated with symptoms’ control in severe asthma patients on biologics, hinting at its potential as a stable, objective marker for severe asthma disease monitoring. Future analyses will seek to validate the usefulness of H2O2 in improving disease management for severe asthma patients on biologics.