Here, you can read more about the scientific background for breath sampling for drug analysis and clinical purposes. Breath Explor collects aerosol particles from exhaled breath through impaction, a quick and non-invasive method of collecting analysis material from the most distal parts of the lung.

Exhaled breath as a specimen for drug testing

Text by Prof. Olof Beck, Professor emeritus at the Department of Clinical Neuroscience, Karolinska Institute

In 2010, the detection of amphetamine in exhaled breath at about 24 h after intake was reported and initiated a new set of work which has explored drug breath testing further. The potential for this new drug testing technology was demonstrated in a study of illicit drug users recovering from acute intoxication. Actual drug intake was determined on the basis of self-report, plasma and urine analysis. The results demonstrated that all studied drug substances were detected in the collected exhaled breath sample at the time they were clinically recovered.

Exhaled breath constitutes an attractive specimen for medical investigations. As compared to alternatives, exhaled breath is always readily accessible, and sampling is convenient for the donor and non-invasive in nature. Exhaled breath may contain as many detectable components as blood and urine. There are already several FDA approved breath-related tests but for volatile compounds.

Exhaled breath contains both volatile and non-volatile compounds. The part that contains the non-volatile components is present in the form of aerosol particles. Particles of sizes about 1 µm in diameter are always present in human breath, most particles are <1 µm in diameter. These particles are formed during inhalation, when small airways re-open and the lining fluid bursts. The particles can be selectively collected using impaction technology used for aerosol particle collection.

The particles are composed of surfactant, a liquid that is secreted in the distal airways and is crucial for lung function. The exact surfactant composition is functionally important and complex, and consists of lipids, mainly phospholipids, and proteins. Both the proteins and lipids are considered important for mechanical and protective functions. Both components may be affected by disease. Thus, surfactant is an interesting source of potential biomarkers.

Listen to Prof emer. Olof Beck’s 2021 presentation on breath analysis in workplace drug testing here.

To read about the Breath Explor sampling device, please click here.

Detecting biomarkers in breath

While research is still ongoing regarding Breath Explor as a diagnostic tool for diseases, it has been confirmed that it is possible to detect biomarkers in our breath samples. Professor Kjell Alving (Respiratory Pharmacology, Uppsala University, Sweden) writes that:

During infections or inflammations in the airways, immunocompetent cells are recruited to the lungs. In particular, lymphocytes (both T and B cells) are recruited. These cells can create organised aggregates classified as tertiary lymphoid tissue, so-called inducible bronchus associated lymphoid tissue (iBALT). iBALT is usually found along the lung arteries, parallel with bronchial airways, and may also be seen near bronchial epithelium. iBALT contains antigen presenting dendritic cells (DC). During an infection, also antibody-producing B cells can be found in iBALT. For example, both IgG and IgA antibodies against flu viruses have been confirmed to be produced in iBALT. iBALT can remain for a long time after a virus has been eliminated. Containing both B and T memory cells, iBALT creates an improved immune system against repeat infections. Immunoglobulins have already been detected in particles in exhaled breath, using a more complex instrument based on particle impaction and LC/MS.

Professor Alving reports finding substantial amounts of immunoglobulin (Ig) A and IgG in our Breath Explor collectors, a result which, together with the device’s user-friendliness, serves as an indication of Breath Explor’s usefulness, and potential, for clinical diagnostics.

To read about Breath Explor’s work against Sars-CoV-2 (also known as Covid-19), please click here.

To read about the Breath Explor sampling device, please click here.

Breath Explor collects non-volatiles through impaction

Prof emer. Beck, Karolinska Institute, describes the Breath Explor sampling device as follows:

Aerosol particles from the airway lining fluid carry non-volatiles from distal parts of the lung, and these aerosol particles are trapped in the three collectors of the Breath Explor sampling device by impaction. The airway lining fluid is composed of lipids and proteins. DPPC, PC16:0/16:0 dipalmitoylphosphatidylcholine, is a characteristic component of surfactant. The amount of DPPC is correlated to the mass of captured particles.

Particles from 10-12 normal breaths is enough material to perform the analysis of drugs. For diagnosis, exhaled breath offers a unique possibility of non-invasive collection of material from the airways. Being non-invasive, exhaled breath collection can be easily performed on large groups of healthy individuals and respiratory patients, thus providing enough power for case control omics studies designed for discovery of new biomarker candidates. Furthermore, exhaled breath sampling is well suited for repeated sampling, opening up for unbiased hypothesis-generating longitudinal studies in respiratory research, as well as follow-up targeted studies.

For information on how to leave a sample with Breath Explor, please click here.

Breath samples compared to various biological fluid samples

Naturally, all sampling methods have their pros and cons. Analysis wise, breath has the benefit of having a simpler chemical matrix than blood, plasma, and urine. Given that the analytical tools used are sufficiently sensitive to handle a relatively small sample size, breath can therefore be easier to analyse. Furthermore, breath has a detection window which answers whether the donor is under the influence of drugs at the time of the sampling, not whether they were in contact with a drug days or even a month ago. This has important implications for tackling questions about, for example, impairment at the workplace or on the road.

Compared to other methods, breath sampling with Breath Explor has benefits which exceed the strictly analytical. To leave a blood sample, for instance, the donor needs to be pricked with a needle, and the test operator needs to handle biohazardous material. Urine samples need to be supervised when given, which can be distressing and intrusive for the donor, and time consuming for the test operator. With urine, there might also be an issue of availability, which holds true also for oral fluid – sometimes caused by emotional stress, or the very drugs you want to test for. Breath sampling, however, is always available, convenient, and entirely non-invasive for the donor. To provide enough material for drug analysis with Breath Explor, the donor simply needs to breathe into the mouthpiece. Thanks to the quick and simple process, one test operator can expect to collect ten Breath Explor samples or more per hour, without needing to handle bio(hazardous)material.

For more information on the analysis of Breath Explor samples, please click here.

For more information on Breath Explor sample preparation, please click here.

To listen to Jack Henion’s presentation on the possibility for roadside Marijuana testing with Breath Explor and mobile LC/CMS analysis equipment, please click here.