Collecting Protein Biomarkers in Breath Using Electret Filters: A Preliminary Method on New Technical Model and Human Study

Evolution of clinical and environmental health applications of exhaled breath research: Review of methods and instrumentation for gas-phase, condensate, and aerosols

Human breath, along with urine and blood, has long been one of the three major biological media for assessing human health and environmental exposure. In fact, the detection of odor on human breath, as described by Hippocrates in 400 BC, is considered the first analytical health assessment tool. Although less common in comparison to contemporary bio-fluids analyses, breath has become an attractive diagnostic medium as sampling is non-invasive, unlimited in timing and volume, and does not require clinical personnel. Exhaled breath, exhaled breath condensate (EBC), and exhaled breath aerosol (EBA) are different types of breath matrices used to assess human health and disease state. Over the past 20 years, breath research has made many advances in assessing health state, overcoming many of its initial challenges related to sampling and analysis. The wide variety of sampling techniques and collection devices that have been developed for these media are discussed herein. The different types of sensors and mass spectrometry instruments currently available for breath analysis are evaluated as well as emerging breath research topics, such as cytokines, security and airport surveillance, cellular respiration, and canine olfaction.

Evaluation of a new simple collection device for sampling of microparticles in exhaled breath

The microparticle fraction of exhaled breath is of interest for developing clinical biomarkers. Exhaled particles may contain non-volatile components from all parts of the airway system, formed during normal breathing. This study aimed to evaluate a new, simple sampling device, based on impaction, for collecting microparticles from exhaled breath. Performance of the new device was compared with that of the existing SensAbues membrane filter device. The analytical work used liquid chromatography-tandem mass spectrometry methods. The new device collected three subsamples and these were separately analysed from eight individuals. No difference was observed between the centre position (0.91 ng/sample) and the side positions (1.01 ng/sample) using major phosphatidylcholine (PC) 16:0/16:0 as the analyte. Exhaled breath was collected from eight patients on methadone maintenance treatment. The intra-individual variability in measured methadone concentration between the three collectors was 8.7%. In another experiment using patients on methadone maintenance treatment, the sampling efficiency was compared with an established filter device. Compared to the existing device, the efficiency of the new device was 121% greater for methadone and 1450% greater for DPPC. The data from lipid analysis also indicated that a larger fraction of the collected material was from the distal parts. Finally, a study using an optical particle counter indicated that the device preferentially collects the larger particle fraction. In conclusion, this study demonstrates the usefulness of the new device for collecting non-volatile components from exhaled breath. The performance of the device was superior to the filter device in several aspects.

Electret filter collects more exhaled albumin than glass condenser: A method comparison based on human study

In recent years, noninvasive diagnosis based on biomarkers in exhaled breath has been extensively studied. The procedure of biomarker collection is a key step. However, the traditional condenser method has low efficacy in collecting nonvolatile compounds especially the protein biomarkers in breath. To solve this deficiency, here we propose an electret filter method.Exhaled breath of 6 volunteers was collected with a glass condenser and an electret filter. The amount of albumin was analyzed. Furthermore, the difference of exhaled albumin between smokers and nonsmokers was evaluated.The electret filter method collected more albumin than the glass condenser method at the same breath volume level (P < .01). Smokers exhaling more albumin than nonsmokers were also observed (P < .01).The electret filter is capable of collecting proteins more effectively than the condenser method. In addition, smokers tend to exhale more albumin than nonsmokers.

Two techniques to sample non-volatiles in breath-exemplified by methadone

The particles in exhaled breath provide a promising matrix for the monitoring of pathological processes in the airways, and also allow exposure to exogenous compounds to be to assessed. The collection is easy to perform and is non-invasive. The aim of the present study is to assess if an exogenous compound-methadone-is distributed in the lining fluid of small airways, and to compare two methods for collecting methadone in particles in exhaled breath. Exhaled particles were collected from 13 subjects receiving methadone maintenance treatment. Two different sampling methods were applied: one based on electret filtration, potentially collecting exhaled particles of all sizes, and one based on impaction, collecting particles in the size range of 0.5-7 μm, known to reflect the respiratory tract lining fluid from the small airways. The collected samples were analyzed by liquid chromatography mass spectrometry, and the impact of different breathing patterns was also investigated. The potential contribution from the oral cavity was investigated by rinsing the mouth with a codeine solution, followed by codeine analysis of the collected exhaled particles by both sampling methods. The results showed that methadone was present in all samples using both methods, but when using the method based on impaction, the concentration of methadone in exhaled breath was less than 1% of the concentration collected by the method based on filtration. Optimizing the breathing pattern to retrieve particles from small airways did not increase the amount of exhaled methadone collected by the filtration method. The contamination from codeine present in the oral cavity was only detected in samples collected by the impaction method. We conclude that methadone is distributed in the respiratory tract lining fluid of small airways. The samples collected by the filtration method most likely contained a contribution from the upper airways/oral fluid in contrast to the impaction method.