To detect bacterial pathogens in exhaled air collected by the Modular Breath Sampler (MBS) by molecular diagnostics and validation of the clinical relevance.
This study contains two phases; a pilot and proof-of-concept phase. Pilot study: Assessment of breath samples from 9 hospital admitted COPD patients to determine whether any potential pathogen could be measured in exhaled air. Proof-of-Concept study: Collection of breath samples from 46 admitted COPD patients to compare results with sputum culturing and c-reactive protein (CRP) in serum. In both studies the patient experience with this innovative way of sampling was assessed using questionnaires.
Pilot study: In 6 out of 9 breath samples relevant bacterial pathogens were detected, e.g., H. influenzae, S. pneumoniae and P. aeruginosa. Proof-of-Concept study: Sputum culturing led to conclusive results in 22% of the cases, whereas 52% breath sample tested positive for relevant pathogen. Most of the sputum and MBS positive patients showed elevated CRP levels in serum, associated with bacterial infection, confirming the relevance of the MBS results.
Pilot study: Breath samples drawn by the MBS can be used for pathogen detection by molecular diagnostics. Proof-of-Concept study: MBS-based pathogen detection is more sensitive than sputum-based detection, 52% vs 22%. In addition, the breath sample is clinically relevant as it correlates with CRP in serum. In addition, positive feedback was received from patients who used the MBS.
Pilot and Proof-of-Concept studies 2019; Assessment of COPD patients admitted with an exacerbation (unpublished).
To determine whether the Modular Breath Sampler (MBS) samples only or primarily the lower respiratory tract.
Saliva, nasopharyngeal swabs, and breath samples were collected from hospital admitted COVID-19 patients. The viral load in the different sample types was determined and compared to assess whether the breath sample can be distinguished from the upper respiratory tract samples (swabs and saliva). We assumed that high correlations of viral loads between swab samples or saliva and breath samples would suggest contamination from the upper respiratory tract, while low correlations would indicate that the breath is derived from the lower respiratory tract.
The viral load of the breath samples did not correlate with saliva nor nasopharyngeal swabs. The figure below displays the viral load in time determined by nasopharyngeal swab sampling on which the positive (blue dots) and negative (black circles) breath samples are projected.
The viral load of MBS samples does not correlate with nasopharyngeal swabs and saliva samples. We conclude that the MBS has proven successful in measuring aerosols from the lower airways loaded with SARS-CoV-2, herewith contagiousness.
‘SARS-CoV-2 RNA in exhaled air of hospitalized COVID-19 patients’, L. Kurver, et al., Scientific Reports, 2022.
To demonstrate the impact of the MBS result on the treatment of patients with cystic fibrosis.
Sputum, swab and breath samples were collected from paediatric patients with cystic fibrosis (CF) to detect airway pathogens, including Pseudomonas aeruginosa an important pathogen which needs to be detected in an early phase to allow immediate treatment to prevent chronic lung damage. We further assessed the patient-friendliness of the sampling method by interviewing the paediatric patients and their parents.
Results between conventional and exhaled breath sampling differed significantly: S. aureus, a frequent colonizer of the upper respiratory tract, was found more often in swab or sputum samples whereas P. aeruginosa known to reside in the lower respiratory tract of CF patients was found more often in breath samples. The figure below displays the comparison of the results between conventional and MBS-based sampling.
Breath samples collected by the MBS show a higher sensitivity for the detection of P. aeruginosa. These results confirm that the MBS samples the lower respiratory tract. Furthermore, this shows promise to be applied for early treatment of CF patients. In addition, most patients and their parents experienced the MBS-based sampling as less burdensome than conventional sampling.
‘Non-invasive diagnostics of pathogenic bacteria using a breath sampler in children with cystic fibrosis’, K. J. van Aerde, et al., Journal of Breath Research, 2022.
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Xheal Diagnostics B.V. is a start-up company and spin-off of the Radboudumc focussed sampling innovations for the lower respiratory tract. Our proprietary exhaled breath sampling technology enables a timely and better diagnosis of lung infections and hence improves patient care.