Exhaled Breath Condensate Research Articles (Page 1)

Air pollution is associated with adverse health effects, particularly on respiratory and cardiovascular systems. Smog, prevalent in Northern India, contains particulate matter (PM10, PM2.5) and gaseous pollutants that can impair pulmonary function. Ambient air pollution can be quantified by the air quality index (AQI). Understanding the acute effects of air quality on respiratory physiology and inflammation is essential. A pilot prospective longitudinal observational study evaluated healthy volunteers during high (HAQI, AQI >350) and low pollution (LAQI, AQI <150) phases. Spirometry and impulse oscillometry (IOS) assessed lung function; and biomarkers (interleukin-6, tumor necrosis factor alpha) were measured from exhaled breath condensate (EBC) and serum. Paired t-tests or Wilcoxon signed-rank tests were used for analysis. A total of 21 participants (mean age 25.4±7.4 years, female 33.3%, body mass index 23.9±3.5 kg/m2) completed measurement at both HAQI (395.7±43.8) and LAQI (85.4±9.7). Spirometry revealed significantly lower slow vital capacity (SVC%, 81.6±11.2 vs. 87.7±7.7%, P = 0.008) and forced vital capacity (FVC%, 86.2±9.8 vs. 90.9±9.4%, P = 0.0005) under HAQI compared to LAQI. Forced expiratory volume at 1 second (FEV1) was also reduced (P < 0.0001), while FEV1/FVC remained unchanged. IOS showed higher airway resistance (R5, R20) during HAQI (P < 0.0001). Inflammatory biomarkers in serum and EBC showed no statistical differences between HAQI and LAQI. Despite measurable differences, spirometry and IOS parameters remained within normal limits. Acute air pollution exposure impairs lung function and increases airway resistance in healthy adults. These findings underscore the need for larger longitudinal studies to clarify the mechanisms linking acute air pollution exposure to chronic health outcomes.

Viral infections have a significant impact on wildlife health, population dynamics, and ecosystem stability. Studies of cetaceans—key species in marine ecosystems—are challenging for viral infection research, owing to difficulties in collecting conventional biological samples. In this study, unmanned aerial vehicles (UAVs) were used in 2024 to noninvasively sample exhaled breath condensates (blows) from five groups of humpback whales (Megaptera novaeangliae) along the coastline of an island in the Pacific Ocean south of Japan. Comprehensive virome analysis revealed viral sequences related to 39 known virus species across 18 families, including nine that infect mammals. Notably, partial sequences of the UL20 gene similar to an alphaherpesvirus previously identified in beluga whales were detected for the first time in the blows from these humpback whales. Our study demonstrates that UAV-based blow sampling is an effective tool for virological surveillance in cetaceans. Moreover, our findings aid in advancing our understanding of the diversity of viruses in marine mammals and supporting the development of noninvasive monitoring strategies that are critical for ensuring the conservation and health of these creatures.

Introduction: Non-smoking chronic obstructive pulmonary disease (COPD) is one of the major contributors among total COPD cases in low- and middle-income countries. This study aimed to investigate pulmonary functions and estimate systemic and airway inflammatory and oxidative stress markers in serum and exhaled breath condensate (EBC) of cigarette-smoking COPD and biomass smoke-exposed COPD patients, comparing them with healthy smokers and healthy non-smokers. Methods: A total of 45 participants were enrolled: smoker COPD (n=10), biomass smoke-exposed COPD (n=10), smoker control (n=10), and non-smoker control (n=15). Pulmonary function tests, including spirometry and impulse oscillometry, were performed. Inflammatory and oxidative stress marker levels in both serum and EBC were estimated. Results: Spirometric parameters, including slow vital capacity (SVC), forced expiratory volume at 1st second (FEV1), forced vital capacity (FVC), and FEV1/FVC were significantly less in COPD groups (smoker/biomass) as compared to controls. Smoker COPD had less FEV1/FVC than biomass-exposed COPD. COPD groups (smoker/biomass) exhibited significant impairment in lung mechanics, characterized by increased peripheral airway resistance (R5-R20), reactance at 5 Hz (X5), and resonant frequency (Fres), indicating involvement of peripheral airways. However, no significant change in lung mechanics exists between smokers’ COPD and biomass-exposed COPD. Among the oxidative stress markers, 8-isoprostane and nitrotyrosine-3 (NT3) levels in EBC were significantly higher in smoker-COPD compared to biomass-exposed COPD and non-smoker controls, respectively. Conclusion: Significant pulmonary function impairment was observed in both smoker COPD and biomass smoke-exposed COPD. Inflammatory and oxidative stress markers are more deranged in smoker COPD than in biomass smoke-exposed COPD and healthy controls.

Exhaled breath condensate (EBC), a non-invasive biofluid that captures biomarkers (small molecules, proteins, nucleic acids) from airway surface fluid, offers novel avenues for pathophysiological research and clinical management of respiratory and systemic diseases. Despite advancements in sample collection and detection, clinical translation remains hindered by critical challenges: inconsistent biomarker standardization leads to cross-study data variability, and the absence of miniaturized equipment limits real-time and portable monitoring. This review systematically synthesizes key EBC research domains: biomarker classification encompasses small molecules, inflammation-related proteins, and pathogens. Collection methods have evolved from passive cooling (e.g., R-Tube) to active strategies (dynamic temperature control, inertial impact). Detection technologies leverage nanomaterials and microfluidics to achieve picogram-level sensitivity, shifting from single-analyte tests to multi-omics integration for comprehensive disease mechanism analysis. Wearable applications progress from proof-of-concept laboratory prototypes to scenario-specific designs, such as smart masks enabling real-time epidemic screening and continuous biomarker monitoring. A novel aspect of this review presents the EBC research framework as a 'technology cluster,' emphasizing the interdisciplinary integration of electrochemical sensing, microfluidic engineering, and the detection and clinical validation of nanomaterials. It combines biomarkers with advanced collection and detection methods to address translation bottlenecks and highlights wearable applications and multi-omics integration, positioning EBC as a revolutionary precision medical tool for early detection and non-invasive monitoring.

Short-chain fatty acids (SCFAs) are metabolic by-products from microbial fermentation of complex carbohydrates and protein. They have gained clinical interest for their protective effects, including within the lung microenvironment. SCFAs are detectable in circulation and exhaled breath condensate (EBC), posing questions as to whether exhaled SCFAs originate from the gut and/or lung microbiota. Mapping SCFAs from the lung could improve our understanding of microbial activity in respiratory conditions. SCFA measurements in EBC were evaluated using a validated gas chromatography-mass spectrometry assay. Six healthy participants ingested sodium acetate, calcium propionate and sodium butyrate to acutely increase circulating SCFAs. EBC samples were collected alongside venous draws, with circulating and exhaled levels compared. A series of additional respiratory sample matrices from patient samples was investigated to gain novel insights into SCFAs within different respiratory biofluids. Serum SCFAs were increased in line with known responses. However, these increases were not observed in EBC, indicating a lack of correlation between circulating and exhaled SCFAs. SCFAs were detected in all additional respiratory biosamples, with EBC and sputum reporting the highest concentrations. Interestingly, branched-chain moieties were notably abundant in sputum, indicating the potential for their local production by bacterial fermentation of lung mucus proteins. SCFAs in EBC do not reflect circulatory levels and, therefore, are not a suitable surrogate measurement to inform on systemic load. These data suggest that exhaled SCFAs are potentially derived from lung microbial metabolism, supporting the need for further investigation into SCFA production, function and diagnostic utility in respiratory health.

The analysis of equine exhaled breath condensate (EBC)lacks standardizedmethodology, and current collection devices are often adapted forresearch. This study evaluates a novel horse-specific EBC collectorand assesses the variability of EBC pH and hydrogen peroxide (H2O2) levels, exploring potential correlations withbronchoalveolar lavage (BAL) and tracheal wash (TW) cytology. Elevenhealthy mixed-breed mares from a teaching herd, with no evidence ofairway abnormalities, were included in this randomized observationalstudy. The collection efficiency of the proposed device was assessed,and intra- and interday variations in EBC pH and H2O2 levels were analyzed. Airway endoscopy, tracheal mucus scoring,and TW and BAL fluid cytology were also performed. EBC pH showed nosignificant intra- (P = 0.631, ES 0.008–0.456)or interday (P = 0.864, ES 0.116–0.365) variation,nor did H2O2 levels (P = 0.953,ES 0.077–0.185; P = 0.929, ES 0.019–0.190,respectively). In this study, no correlations were found between EBCparameters and BAL or TW cytology. However, 34.5% of pH samples and32.7% of H2O2 samples were insufficient foranalysis due to low sample volume. These findings suggest that EBCcollection using the horse-specific device is feasible and that pHand H2O2 levels remain stable regardless ofcollection time. However, further refinement of the device is necessaryto improve sample yield and ensure reliable analysis.

Millions of people worldwide are exposed to environmental arsenic in drinking water, resulting in both malignant and nonmalignant diseases. Interestingly, early life exposure by itself is sufficient to produce higher incidences of these diseases later in life. Based on the delayed onset of disease, we hypothesized that early life arsenic exposure would also induce long-term alterations in the metabolic profile. The objective of this study was to examine metabolomic biomarkers in exhaled breath condensate (EBC) of individuals exposed to arsenic in drinking water early in life, but not later. One hundred and fifty subjects (75 males and 75 females) were initially recruited from Antofagasta, Chile, some of whom were exposed to high water arsenic levels (⩾870µg l-1; HighAE group), and others, low water arsenic levels (⩽110µg l-1; LowAE group) early in life (1958-1970). EBC samples were collected for targeted and untargeted metabolomic biomarker analysis. The results showed significantly shorter individuals and reduced pulmonary functions (forced vital capacity, FVC and forced expiratory volume in 1 s, FEV1) in both males and females in the high-arsenic groups. Males exposed to high arsenic levels also had reduced red blood cell concentrations, as well as higher concentrations of the oxidative stress metabolites 8-OH-2dG and 8-iso-PGF2α. Females in the high-arsenic group showed reductions in 8-OH-2dG. Untargeted analysis revealed metabolomic markers that differentiated the HighAE group from the LowAE group, with a subgroup of markers whose concentrations were proportional to the level of arsenic exposure. Targeted and untargeted analyses of EBC using liquid chromatography-mass spectrometry indicated that adults exposed to high arsenic levels in drinking water in utero and during early childhood retained a modified metabolic profile 47 years after the end of exposure.

Integrated breath volatolomics and metabolomics analyses reveals novel biomarker panels for the diagnosis of chronic obstructive pulmonary disease.

Tuberculosis remains the leading cause of death by a single infectious agent worldwide, with over 10 million cases annually. Despite global efforts, delayed or missed diagnoses continue to fuel transmission and mortality, particularly in resource-limited settings. This review outlines both the current diagnostic standards - microscopy, culture, and nucleic acid amplification tests - and highlights promising innovations aimed at improving diagnosis of tuberculosis disease. Novel approaches include stool polymerase chain reaction (PCR), CRISPR (clustered regularly interspaced short palindromic repeats)-based detection of circulating cell-free DNA (cfDNA), transcriptomic signatures, molecular bacterial load assay (MBLA), lipoarabinomannan (LAM) detection in urine or sputum, and non-invasive sampling techniques using exhaled breath condensate, face masks or oral swabs. Furthermore, advancements in imaging technologies and AI (artificial intelligence)-based tools may enhance diagnostic accuracy. Together, these developments have the potential to accelerate and simplify tuberculosis diagnostics in the future.

Precision medicine to diagnose asthma in preschool children: comparison of clinical scores, lung function, biomarkers, and genetic tests.

To characterize the bioaccessibility of inhaled organophosphate esters (OPEs) in the respiratory tract, we employed a highly idealized mouth-throat model to investigate the occurrence, distribution, and deposition of 17 OPEs in airborne particulate matter (PM1, PM1-2.5, and PM2.5-10; n = 80 pairs) and gas phases (n = 48) under gradient temperature and humidity. OPEs concentrations were also measured in exhaled breath condensate (EBC; n = 50) and sputum (n = 30) from 30 adults. Total median ∑17OPEs concentrations in inhaled air were 4.7 ± 0.4 ng/m3, with ∼82.7% of particle-phase OPEs deposited in the upper respiratory tract and almost all gas-phase OPEs reaching the lungs. OPEs in PM2.5-10 showed the highest deposition efficiency in the upper respiratory tract (93.8%), followed by PM1-2.5 (77.5%) and PM1 (76.2%). Humidity enhanced deposition, whereas temperature had a minimal effect. Median ∑17OPEs concentrations in EBC and sputum were 0.29 ± 0.03 ng/m3 and 0.22 ± 0.06 ng/mL, indicating that ∼20.8% of inhaled ∑17OPEs was exhaled. Significant correlations (p < 0.05) between airborne particle-phase and exhaled OPEs suggest that the exhaled fraction derives mainly from particles. Bioaccessibility of 17 OPEs ranged from 32.9% [bis(2-tert-butylphenyl)phenyl phosphate] to 92.7% [tris(1-chloromethyl-2-chloroethyl) phosphate].

IntroductionTo measure inflammatory biomarkers of radiation pneumonitis in the exhaled breath condensate (EBC) and serum of patients with stage III non-small cell lung cancer (NSCLC) treated with chemoradiotherapy (CRT).MethodsThis single-arm pilot study (NCT04040244) enrolled adults with stage III NSCLC planned for treatment with definitive CRT (60 Gy). EBC and serum samples were collected at baseline (W0) and at 2-, 6-, and 10-weeks after CRT initiation. EBC and serum concentrations of TGF-β1, IL-1α, IL-6, and IL-10, and cartilage oligomeric matrix protein (COMP) were measured in duplicate. Unadjusted mean biomarker levels were described over time.ResultsSamples were available for analysis from 11 out of 16 patients enrolled before the trial was closed early due to the COVID-19 public health emergency. Measurable biomarkers were present in 288 of 302 (95%) available EBC samples and 273 of 278 (98%) serum samples. Mean concentration of TGF-β1, IL-1α, IL-6, IL-10, and COMP over time is described. Mean concentration of TGF-β1 ranged from 81 to 101 pg/mL in EBC and 2819 to 5403 in serum. All biomarkers tested had numerically lower concentrations in EBC than serum, except for IL-10.ConclusionExhaled breath-based analysis of RP-associated biomarkers is feasible, with most available samples having measurable levels of substrate across the multiple biomarkers tested. Given the limited sample size, no tests for association between EBC or serum biomarkers and the development of radiation pneumonitis or pulmonary fibrosis were possible. Larger prospective studies are warranted to determine the association between breath biomarkers and clinical outcomes. Future studies may expand upon this work by integrating clinical and dosimetric factors, using a broader range of inflammatory biomarkers, using a multi-omics approach to identify novel biomarkers, or incorporating breath volatile organic compound profiles.

MicroRNAs in exhaled breath Condensate: Novel non-invasive biomarkers for tuberculosis diagnosis.

Molecular structural transformation from the D–A to D–D’ of an AIEgen for the highly sensitive detection of hydrogen peroxide in exhaled breath condensate

Obtaining multiple sample types from the same exhaled breath condensate (EBC) sample can reduce the number of samples needed for diagnostics purposes, allowing for sampling to be completed quicker and making it even easier to collect breath from patients. In this study, we performed analysis for volatile organic compounds (VOCs) and proteins from the same EBC sample. Pooled EBC samples were split into two groups: three samples that utilized immersion thin film-solid phase microextraction (TF-SPME) sampling for VOC analysis and three samples that did not undergo TF-SPME sampling (non-TF-SPME). All six EBC samples were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS) for proteomics analysis. VOCs were analyzed via two-dimensional gas chromatography-mass spectrometry (GC x GC-MS). One hundred and eighty-four VOCs were found to be more abundant in EBC samples compared to blank or controls. There was no significant difference in the number of proteins detected in the TF-SPME samples compared to the non-TF-SPME samples and 144 of the 206 total unique proteins detected were found in both sample groups. These results indicate that TF-SPME sampling does not negatively affect the number of proteins that can be detected in EBC. This work is a step towards linking VOC and protein data together to obtain multi-omics breath data from a single breath sample. EBC samples were collected as part of a vaccination clinical trial (NCT05346302).

Utilizing copper-doped graphene quantum dots as a fluorescent sensor for determination of carbamazepine in exhaled breath condensate.

Non-invasive quantification of methadone in exhaled breath condensates using PtNPs/AgNP-modified GCE: an electrochemical sensor for narcotic bioanalysis

Introduction: This study aimed to analyze exhaled breath condensate (EBC) for 8-oxoguanine (8-oxoGua), an oxidative stress biomarker among waterpipe (WP) smokers. Methods: In a within-subject pre-post exposure design, thirty waterpipe smokers completed two 45 min laboratory sessions. EBC was analyzed for 8-oxoGua before and after WP smoking. Median differences between time points (pre vs. post) were assessed using the Wilcoxon sign rank test, with significance defined as p < 0.05. Results: The analysis included 59 WP smoking sessions. Participants had a median age of 24 years (IQR: 21–25), with 62.1% being female. Most had a bachelor’s degree or less (62.1%), and over half were students (55.2%), while 34.5% were employed. The average age for first WP use was 18.6 years, with participants reporting a median of three WP smoking sessions per month. Results indicate a median increase in 8-oxoGua among participants from 5.4 ng/mL (IQR: 8.8) before the smoking session to 7.6 ng/mL after (IQR: 15.7; p < 0.001). Conclusions: This study is the first to examine 8-oxoGua in EBC. Findings provide strong evidence of WP smoking’s contribution to oxidative stress in the airways. It justifies the use of EBC to study the exposure to markers of oxidative stress with emerging tobacco use methods such as the waterpipe.

Respiratory microbiota and lipids are closely associated with airway inflammation. This study aimed to analyze the correlations among the respiratory microbiome, the airway glycerophospholipid-sphingolipid profiles, and airway inflammation in patients with asthma. We conducted a cross-sectional study involving 61 patients with asthma and 17 healthy controls. Targeted phospholipidomics was performed on exhaled breath condensate (EBC) samples, and microbial composition was analyzed via the 16S rDNA sequencing of induced sputum. Asthma patients exhibited significant alterations in the EBC lipid profiles, with reduced levels of multiple ceramides (Cer) and glycerophospholipids, including phosphatidylethanolamine (PE) and phosphatidylcholine (PC), compared with healthy controls. These lipids were inversely correlated with the sputum interleukin-4 (IL-4) levels. Microbiome analysis revealed an increased abundance of Leptotrichia and Parasutterella in asthma patients, both positively associated with IL-4. Correlation analysis highlighted a potential interaction network involving PA, PE, ceramides, Streptococcus, Corynebacterium, Parasutterella, and Leptotrichia. Specific alterations in airway microbiota and phospholipid metabolism are associated with asthma-related inflammation, supporting the concept of a microbiota-phospholipid-immune axis and providing potential targets for future mechanistic and therapeutic studies.

Abstract Developing wearable devices with high sensitivity, low‐pressure detection, and multi‐signal monitoring capabilities is critical for the effective diagnosis of respiratory diseases. Here, this work reports a wearable mask that integrates with a printed circuit board (PCB) and Bluetooth Low Energy (BLE) module, in tandem with ionogel‐based microneedle patches (IMN‐1/2) featuring a regularized microarray structure. By leveraging its gradient morphology, IMN‐1/2 achieves a pressure detection limit as low as 0.3 Pa and an ultrahigh sensitivity of 2980.23 kPa⁻¹ in low‐pressure range, enabling the effective monitoring of extremely weak breathing pressure signals. Moreover, hydrophilic N,N‐dimethylacrylamide (DMAA) of IMN‐1/2 impart the patches with distinct amphiphilic characteristics that limited swelling while allowing for slow, controlled water absorption. When weakly alkaline exhaled breath condensate (EBC) permeates the IMN‐1/2 structure, it alters the charge state of cationic fluorescent crosslinkers, leading to a reduction in fluorescence intensity; this pH‐responsive behavior facilitated long‐term monitoring and potential diagnosis of respiratory alkalosis. Furthermore, the strong adhesion of IMN‐1/2 enhances the sealing integrity of IMN‐1/2‐integrated masks, physically restricting CO2 inhalation and reducing arterial blood pH values of wearers, thus enabling physical therapy for respiratory alkalosis. This work demonstrates efficient ultralow‐pressure monitoring, expanding the diagnostic capabilities of piezo‐resistive pressure sensors through structural design.