ERJ Open Research

Therapeutic bacteriophages are promising alternatives to antibiotics for treating antimicrobial-resistant bacterial infections. For pulmonary infections, direct respiratory delivery offers therapeutic advantages; however, preclinical evaluation of respiratory safety remains underdeveloped. Bacteriophages exhibit genomic and biological diversity, and safety cannot be assumed for individual candidates. Here, we evaluated the respiratory safety of lytic Staphylococcus aureus bacteriophages, Koomba kaat 1 and Biyabeda mokiny 1, using human and murine preclinical models. Differentiated primary airway epithelial cells derived from six healthy paediatric donors were exposed apically to purified phage (1 x 109 PFU/mL) for 24 hours. Barrier integrity, epithelial morphology, mucus production, cytotoxicity, and interleukin-8 release were assessed. Safety was further investigated in adult C57BL/6J mice receiving intranasal phage administration (1 x 109 PFU) twice daily (14 days). Clinical observations, body weight, organ pathology, blood biochemistry, bronchoalveolar lavage cellularity, protein concentration, and inflammatory mediators were evaluated. Neither phage altered epithelial morphology, barrier integrity, mucus production, cytotoxicity, nor inflammatory responses in differentiated cultures. Repeated intranasal administration was well tolerated in vivo, with no adverse clinical signs, weight loss, macroscopic pathology, or treatment-associated changes in pulmonary cellularity or tissue histopathology. Differences in blood biochemistry and inflammatory mediators were small and not accompanied by epithelial injury or pulmonary inflammation. Collectively, these findings demonstrate that Koomba kaat 1 and Biyabeda mokiny 1 exhibit favourable safety profiles following repeated airway administration. This study establishes a comprehensive framework for the preclinical respiratory safety assessment of bacteriophages and provides support for the clinical development of inhaled phage for S. aureus respiratory infections.

Chronic Pseudomonas aeruginosa lung infections are becoming harder to treat due to global escalation of antimicrobial resistance (AMR). Bacteriophage (phage) therapy has emerged as a promising adjunct to conventional antibiotics, especially in chronic lung infections such as those seen in cystic fibrosis (CF). However, phage monotherapy may be limited by the emergence of phage-resistant bacterial populations and there remains limited preclinical evidence evaluating both antimicrobial efficacy and host safety in physiologically relevant human airway models. Here, we evaluated the safety and antimicrobial activity of Kara-mokiny 3, a myovirus bacteriophage, alone and in combination with subinhibitory concentrations of tobramycin using fully differentiated paediatric primary airway epithelial cells (pAECs) cultured at the air-liquid interface (ALI). Kara-mokiny 3 rapidly reduced P. aeruginosa viability and exhibited synergistic activity with tobramycin, resulting in significantly greater bacterial killing than either treatment alone. Importantly, phage treatment replicated efficiently in the presence of its bacterial host while preserving epithelial morphology, mucin production and epithelial barrier architecture., without inducing cytotoxicity or excessive IL-6 and IL-8 inflammatory responses. These findings demonstrate that phage-antibiotic combination therapy can enhance antimicrobial activity while maintaining epithelial safety in a physiologically relevant human airway model. This study represents one of the first comprehensive evaluations of phage-antibiotic combination therapy in differentiated primary airway epithelial cultures, providing important preclinical evidence supporting the development of personalised phage-based therapies for the treatment of MDR pulmonary infections. ImportanceThe rise of MDR P. aeruginosa has created an urgent need for alternative treatment strategies for chronic lung infections. Although phage therapy is receiving increasing clinical attention, there is limited evidence evaluating its safety and efficacy in physiologically relevant human airway models. Using differentiated primary airway epithelial cultures, we demonstrate that a phage-antibiotic combination reduces bacterial burden without compromising epithelial integrity and toxicity or excessive inflammatory responses. These findings provide translational evidence supporting phage-antibiotic combination therapy and highlight the value of primary airway epithelial models for the preclinical assessment of emerging antimicrobial interventions, supporting the translation of personalised phage therapies.

Background Upper airway disease is common in primary ciliary dyskinesia (PCD), but management evidence is limited. We aimed to describe management practices and identify factors influencing management decisions. Methods Using data from the Ear-Nose-Throat (ENT) Prospective International Cohort of patients with PCD (EPIC-PCD) and an ENT-specialist survey across participating centres, we described management practices recorded at routine follow-up. We assessed clinical factors associated with practices via mixed-effects logistic regression models. In a subgroup of patients, we assessed factors associated with initiation or discontinuation of practices. Results We included 579 patients: median age 15 years, 46% female. Nasal rinsing (54%) and nasal corticosteroids (22%) were most frequently prescribed. Among 466 patients with available data, 47 had grommets (10%) and 42 hearing aids (9%). Nasal corticosteroids and rinsing were more frequently prescribed in patients with polyps (odds ratio [OR] 3.74, 95% confidence interval [CI] 1.80-7.76; OR 3.39, 95% CI 1.37-8.37) or turbinate hypertrophy (OR 1.89, 95% CI 1.03-3.47; OR 2.89, 95% CI 1.55-5.38), and upper airway nebulisation in patients with frequent nasal symptoms (OR 2.86, 95% CI 1.11-7.39). Management practices differed between centres, as seen also by the specialists survey responses. In 177 patients with multiple visits, initiation of nasal rinsing was associated with frequent nasal symptoms (OR 3.18, 95% CI 1.24-8.18) and turbinate hypertrophy (OR 3.21, 95% CI 1.20-8.59). Conclusion Upper airway disease management in PCD varies and is partly guided by symptom burden and clinical findings. This variation across centres highlights the need for care standardisation and PCD-specific management guidelines.

Abstract Background Fibrotic interstitial lung disease (F-ILD) has high mortality. Evidence suggests short telomere causality and sex hormone interactions. STARSHIP aimed to assess feasibility for future F-ILD sex hormone trials. Methods Leukocyte telomere length (LTL), complete blood count, sex hormone (testosterone and oestrogen), sex hormone binding globulin (SHBG) and albumin concentrations were determined in 102 F-ILD outpatients (age 49-89, male N=80 [78%]) and age/sex-matched controls (ASMCs). Patients undertook routine pulmonary function tests, 93 (91%) participated in bespoke telephone interviews. Survival was assessed at median 33 (28-39) months. Results 77/79 (97.4%) male patients had haemoglobin and haematocrit below the upper reference limit. Mean LTL was shorter for patients than ASMCs (4.57kb [95%CI:4.46-4.69] vs 4.78kb [95%CI:4.67-4.89]; p<0.006). SHBG concentrations were higher for patients. Mean bioavailable testosterone was lower for N=80 male patients than ASMCs (4.95nmol/L [95%CI:4.50-5.41] vs 6.40nmol/L [95%CI:5.82-6.98]; p<0.0001). Post-menopausal oestrogen concentrations were low for female patients and controls. Mean free androgen index (FAI) was low for female patients but not ASMCs (mean 0.51 [95%CI:0.35-0.67] vs 1.23 [95%CI:0.77-1.69]; p=0.0036, N=22). Age/BMI-adjusted bioavailable testosterone concentration in male patients correlated with both DLCO% (=3.31, p=2.4x10-4) and FVC% (=2.76, p=0.0030). FVC% associated with FAI in females (=34.3, p=0.0029). In all-confounder-adjusted Cox analysis, low free testosterone associated with mortality (HR=2.66, p=0.023, N=77) in male patients. Lower FAI (adjusted for age/lung function) suggested similar effects but more studies needed for females (HR=3.59, p=0.22, N=18). Conclusions ILD patients have low sex hormones concentration(s), which associated with reduced lung function and survival. Sex hormone supplementation studies are needed.

Objectives Genetic testing is increasingly used in the diagnosis and management of respiratory conditions, including pulmonary fibrosis (PF). The perspectives of people with PF and healthcare professionals (HCP) on the use of genetic testing remain largely unexplored. Methods A qualitative study was undertaken. People living with PF, their caregivers, and HCP were invited to undertake a semi-structured interview. Interviews were conducted via videoconference or telephone, audio-recorded, and transcribed verbatim. Data were analysed by two researchers using inductive thematic analysis. Results Thirty-eight participants; 15 people living with PF, 1 caregiver, and 22 HCPs were interviewed. Analysis revealed three key themes. Genetic testing in PF was valued by all groups; people with PF wanted testing now, whilst respiratory physicians were cautious, citing their uncertainty regarding clinical value. All groups desired more information and support; people with PF desired a better understanding of terminology, whilst genetic counsellors wanted to better understand PF. No single model for returning genetic results in PF was identified, however resources, multidisciplinary care, and timely return of results was considered important. Conclusion Genetic testing is valued by people with PF and their HCP, but uncertainties remain regarding whether it should be offered and how results should be best communicated.

In 1992, inhaled NO (iNO) at low doses entered the practice of medicine for cardiopulmonary indications. Recently, iNO at higher doses has been tested in diverse pulmonary infections. However, nothing is known about the ability of exogenous NO gas to kill Mycobacterium tuberculosis (Mtb), the leading cause of death from infection between major viral pandemics. Here we mimicked exposure conditions used in recent human studies of high-dose iNO to explore the effects of NO gas against Mtb in vitro and in mice. We saw a profound bactericidal effect of NO gas in vitro against Mtb incubated in shallow, mildly acidic fluid. Mtb-infected mice tolerated inhaled NO well, except for developing more methemoglobinemia than humans at the same level of exposure. In Mtb-infected mice with poorly aerated pulmonary infiltrates, inhaled NO had an anti-inflammatory effect but did not reduce the bacterial burden. These results may help inform the decision whether to test inhaled NO as an adjunctive treatment for tuberculosis, and if so, in what settings and with what goals.

Purpose Because simple symptom counts treat all symptoms as equally important and may not adequately capture the HRQoL impact of heterogeneous post-COVID-19 symptoms, we aimed to develop an HRQoL-anchored symptom severity score providing an interpretable measure of post-COVID-19 disease burden. Methods Baseline data from the population-based EPILOC and EPILOC Omicron surveys (adults aged 18-65 years) were used to develop a symptom-based severity score anchored to physical and mental HRQoL assessed with the SF-12. A two-stage modelling approach was applied to identify HRQoL-relevant symptoms and to derive symptom-specific weights for physical and mental component scores, incorporating 30 ordinal symptom severity variables. Symptom-specific weights were extracted to compute physical, mental, and composite severity scores. Score interpretation was examined using external reference measures, including EPILOC case status, self-reported health recovery, and functional consequences. Results A total of 19,004 participants (mean age 44.3 years, 59.6% female) were included. Sixteen symptoms contributed to the physical and eleven to the mental HRQoL score, with a limited subset accounting for most of the HRQoL loss. Severity scores were heavily right-skewed, with 50.6% of participants showing no measurable HRQoL impairment. Higher scores correlated with lower self-reported recovery, and increased probability of rehabilitation use and health-related changes in working time, supporting convergent and criterion-related validity. Conclusions This study introduces a transparent, HRQoL-anchored symptom severity score that measures graded post-COVID-19 burden beyond simple symptom counts. The score may be particularly suited for longitudinal assessment of recovery trajectories.

Background Exposure to environmental tobacco smoke (ETS) negatively affects children`s health, but few studies examined parental smoking behaviour in families of children with respiratory diseases. We studied parental smoking prevalence, characteristics, and changes over one year among families in the Swiss Paediatric Airway Cohort (SPAC). Methods We included children aged 0-17 years referred to paediatric respiratory outpatient clinics in Switzerland from 2017 to 2024. Parents answered a questionnaire at the initial clinic visit and again after one year. We used multivariable logistic regression to explore the characteristics of mothers and fathers who smoked and assessed changes in smoking behavior over one year. Results Among 4,199 children (median age 9 years [IQR 5-12]), 31% were exposed to parental smoking at baseline (paternal smoking: 16%; maternal smoking: 6%; both parents smoking: 9%). Mothers were more likely to smoke if they had a lower education level (OR 2.0, 95%CI 1.6-2.5 for compulsory education vs university education), did not have Swiss nationality (OR 1.3, 1.0-1.6) and lived in a socially disadvantaged neighborhood (OR 1.3, 1.0-1.7). Similar associations were observed for fathers. In addition, fathers were more likely to smoke if they were unemployed (OR 2.0, 1.3-3.2 vs having a full-time job. The strongest predictor of smoking was having a partner who smoked, with ORs above 6 for both mothers and fathers. Parents of 2,338 children completed the one-year follow-up questionnaire. Data from 2226 mothers and 1895 fathers showed that among baseline smokers with follow-up data, 225 (78%) mothers and 382 (81%) of fathers continued smoking, and only 63 (22%) of mothers and 90 (19%) of fathers quit. Among baseline non-smokers, 47 (2%) mothers and 54 (3%) fathers started smoking. Conclusions One-third of children consulting respiratory specialists in Switzerland are exposed to parental smoking. ETS exposure was strongly associated with socio-economic factors. Even after visiting a specialized clinic, most parents continued to smoke. This highlights the urgent need for stronger national smoking policies and targeted support to help these parents quit and stay smoke-free.

Background: The systemic immune responses associated with persistent respiratory symptoms (PRS) after exposure to airborne environmental pollutants remain poorly understood. Objective: To identify immune disturbances associated with PRS, defined as persistent wheeze, cough, or breathlessness, we examined systemic immune responses and airway function in a cross-sectional cohort with detailed histories of airborne pollutant exposure. Methods: Never-smoking post-deployment Veterans with PRS (n=16) or without PRS (n=24) underwent chest computed tomography, pulmonary function testing, and oscillometry to assess structural and functional airway abnormalities. Peripheral blood mononuclear cells (PBMCs) were stimulated with anti-CD3/CD28 antibodies, lipopolysaccharide, or {beta}-glucan, and cytokine production was measured. Correlation analyses evaluated associations between cytokine responses and physiological measures of airway function. Results: Oscillometry, but not conventional pulmonary function testing or chest computed tomography, detected small-airway abnormalities in participants with PRS, including significantly greater frequency dependence of resistance and higher resonant frequency. Baseline PBMC cytokine concentrations were similar between groups. After stimulation, however, PBMCs from participants with PRS showed increased IL-17A production consistent with a type 17 (T17) response; innate stimulation also increased the type 2 (T2) cytokines IL-33 and IL-4. T2/T17 cytokine responses correlated positively with oscillometric measures of small-airway dysfunction. Conclusion: Individuals with PRS exhibited a stimulus-dependent systemic T2/T17 immune signature that was associated with early small-airway dysfunction. Clinical Implication: Stimulus-dependent systemic immune profiling, combined with oscillometry, may help identify early respiratory abnormalities in pollutant-exposed individuals whose conventional pulmonary tests remain normal.

Background: Anxiety affects 22-56% of patients with COPD. It is independently associated with increased exacerbations, readmissions, and mortality. Medical hypnosis transiently alleviates state anxiety in severe COPD, and attenuates experimentally-induced dyspnoea in healthy volunteers. We aimed to assess the efficacy of hypnosis as adjunct therapy for anxiety during Pulmonary Rehabilitation (PR) versus an active comparator controlling for general motivation and relaxation. Methods. HYPNOBPCO_2 was a single-centre, phase 2, cluster-randomised, active-comparator, parallel-group, superiority trial done at Centre Hospitalier de Bligny, France. Adults +30 years with established COPD, mMRC dyspnoea grade +2, and +10 pack-years were eligible. Consecutive pulmonary rehabilitation cohorts (clusters) were randomly assigned (1:1) to medical hypnosis or structured relaxation, both adjunctive to a 4-week inpatient PR. The primary outcome was the six-item State-Trait Anxiety Inventory (STAI-6) at week 4, analysed in the intention-to-treat population. Secondary outcomes were sensory and affective dyspnoea (Multidimensional Dyspnea Profile sensory and affective sub-scales, COPD Assessment Test) and functional capacity (6-minute walk distance). A moderation analysis tested whether the hypnosis effect varied with baseline sensory and affective dyspnoea burden using Bayesian inference. This trial was registered prospectively (NCT04868357) and the protocol published. Findings. Between 27/09/2021 and 31/01/2024, 79 participants in 24 clusters were randomised (medical hypnosis n = 36, age 64.9 [8.3], 20 female; relaxation n = 43, age 67.4 [9.1], 23 female). Anxiety improved in both arms (deltaSTAI-6 = -5.72, posterior probability of reduction beyond MCID = 0.93). Medical hypnosis did not show an advantage over relaxation overall (deltaSTAI-6 = 0.95; posterior probability of reduction beyond MCID = 0.12). Medical hypnosis did show an advantage that scaled with baseline dyspnoea profile: in patients with high sensory and low affective burden, the predicted anxiety reduction relative to relaxation was larger and more probable (deltaSTAI-6 = -9.26; posterior probability of reduction beyond the 3-point MCID = 0.81). No clinically important safety issues were associated with either intervention and there were no deaths. Interpretation. Anxiety improved under both adjunctive mind-body interventions. The usefulness of hypnosis beyond relaxation was predicted by baseline dyspnoea profile, concentrating in patients with predominantly sensory burden. Future trials should focus on evaluating complementary interventions against burden phenotypes, ultimately paving the way for personalized interventions. Funding. Helebor Foundation; Agence Nationale de la Recherche.

Background: Monitoring Pseudomonas aeruginosa (P. aeruginosa) infection in people with cystic fibrosis (pwCF) is essential for early detection, targeted treatment, and prevention of chronification. Sputum culture is the current standard, yet many patients, particularly those receiving CFTR modulator therapy, struggle to expectorate sputum. Microbial aerosols from the respiratory tract offer a non-invasive alternative. This proof-of-principle study assessed the accuracy and feasibility of the AveloMask, a novel breath aerosol collection kit paired with qPCR detection. Methods: Adult pwCF and bronchiectasis patients attending routine monitoring visits and healthy controls were enrolled in a cross-sectional study. Participants wore the mask for 30 minutes, followed by 20 instructed coughs. Mask filters were tested with a triplex qPCR assay targeting P. aeruginosa specific ecfX and gyrB, and human RPP30 as an endogenous control. Accuracy was evaluated using a composite reference standard (sputum culture and PCR). Results: Of 25 patients enrolled, 23 were included in the analyses. Sensitivity was 12/19 (63.2%) for breath qPCR versus 15/19 (78.9%) for sputum culture. Breath qPCR missed 5 cases detected by sputum culture but detected 2 sputum culture-negative/qPCR-positive cases. Specificity of breath qPCR was 100% in 4 patients and 15 healthy controls. RPP30 was detected in all mask samples. AveloMask was perceived as easy to use, with many patients preferring it over sputum collection. Discussion: Mask-based breath collection demonstrated promising diagnostic accuracy for detection of P. aeruginosa. Breath sampling may complement or partially substitute sputum-based diagnostics, especially in patients unable to expectorate. Further studies are needed to define its clinical role.

Research on Pseudomonas aeruginosa adaptation in cystic fibrosis (CF) has historically relied on comparing chronic isolates to laboratory reference strains, or evolving reference strains in environments simulating chronic CF. This work has established a small set of genes, including lasR, mucA, and mexZ, as canonical markers of CF patho-adaptation. However, without broad non-CF comparators, it remains unclear how specific these signatures are to CF. We used a structured literature review to define 20 historically emphasized "canonical CF genes", then evaluated their mutational patterns across 4,475 genetically distinct P. aeruginosa genomes from seven defined clinical and environmental contexts. We tested four competing hypotheses: (1) enrichment in adult CF alone, (2) in adult and pediatric CF combined, (3) in chronic lung infections broadly (including non-CF bronchiectasis), or (4) no strong environment-specific enrichment. We found little evidence that canonical gene mutations were specifically enriched in adult CF or CF more broadly. Instead, loss-of-function and individual mutations in genes including mucA, mexB, and mexZ were enriched across chronic lung infections, while most canonical genes (including lasR) showed no strong environment-specific enrichment. These results demonstrate that a canon of genes believed to drive patho-adaptation in CF instead largely reflects the narrow comparative framework of past studies rather than CF-exclusive selection. Our findings emphasize shared evolutionary pressures between CF and non-CF bronchiectasis, highlighting opportunities to exchange research and therapeutic insights across chronic infection clinical contexts.

Background Elexacaftor-tezacaftor-ivacaftor (ETI) has been demonstrated to improve lung function in clinical trials; however, evidence describing effects on trajectories and whether long-term improvements are sustained (>1-year) is lacking. We estimated within-person lung clearance index (LCI) trajectories before and after ETI initiation, assessing changes in level and rate of change, alongside acute LCI change, up to three years after ETI initiation. Methods Prospective observational study of children at a tertiary hospital. Children aged 3-17 years with [&ge;]2 LCI testing occasions (i) before and (ii) after starting ETI were used to describe lung function trajectories. Children with [&ge;]1 pre-ETI and [&ge;]1 post-ETI LCI occasion(s) were used to describe acute LCI change after ETI initiation. Age-adjusted LCI trajectories for time periods (i) before and (ii) after ETI initiation were estimated using linear mixed-effects models, and pre- and post-ETI LCIs were compared using paired Wilcoxon tests. Results Mean pre-ETI and post-ETI longitudinal changes in LCI were -0.007 (95% CI: -0.28, 0.27; n=35) and 0.12 (95% CI: -0.17, 0.41; n=20) turnovers per year, respectively. Before ETI initiation, 57% (30/53) of patients had an LCI[&ge;]7.1 turnovers (indicating impaired lung function), compared to 26% (14/53) post-ETI, with a median LCI difference of -0.70 (95% CI -0.84, -0.46; p<0.001) turnovers. Within-individual variability in LCI decreased post-ETI. Conclusions Our real-world data within a unique longitudinal study provide a comprehensive picture of ETI benefit by outlining not only acute improvement in LCI but maintained stability in LCI trajectories and improved LCI stability sustained up to three years post-initiation.

Rationale: Pulmonary hypertension is defined by pulmonary hemodynamics, but diagnostic and prognostic biomarkers remain limited. Nuclear magnetic resonance (NMR) spectroscopy provides detailed insights, particularly in the lipid metabolism. Objectives: To explore circulating NMR-derived metabolites and lipoprotein-related parameters for their association with pulmonary hemodynamics and to analyse their prognostic properties in pulmonary arterial hypertension (PAH). Methods: Retrospective analysis of a PAH cohort with complete diagnostic workup including right heart catheterization and baseline serum samples, from the prospective GRaz Pulmonary Hypertension-Metabolism (GRAPH-M) registry. Measurements: NMR-derived metabolites and lipoprotein-related parameters were analyzed for their association with clinically relevant parameters of PAH. We defined PHIHDL, a score derived from high-density lipoprotein (HDL) related measures based on their strong association with pulmonary hemodynamics, and evaluated its prognostic value. Results: We included 100 patients with PAH treated at the PH clinic of LKH University Hospital, Medical University of Graz, between 2011 and 2021. Age was 61{+/-}15 years, female/male ratio 2.5, BMI 26 {+/-}7 kg/m2, mPAP 41{+/-}16 mmHg, PAWP 8.8{+/-}3.2 mmHg, PVR 8.0{+/-}4.9 WU, and median survival was 8.0 years. During follow-up, 46 patients died. We identified a cluster of 12 HDL-related measures that showed significant inverse association to pulmonary hemodynamics and derived PHIHDL from the reversed scaled average of these particles. PHIHDL was associated with all-cause mortality after adjustment for age and sex (HR 2.96, 95% CI 1.52-5.70), independent of the clinical risk scores COMPERA 2.0 and REVEAL Lite2. Conclusion: PHIHDL, a pulmonary hemodynamics-based metabolomic score, provides independent prognostic information beyond established risk scores in PAH.

Inadequate autophagy promotes smoking-induced cellular senescence involved in chronic obstructive pulmonary disease (COPD) pathogenesis. Transcription factor EB (TFEB) is a master regulator of the autophagy-lysosome axis. For the first time, we investigated the therapeutic potential of pemafibrate, a putative TFEB inducer. COPD lung epithelial cells showed reduced TFEB expression. Pemafibrate enhanced autophagy/mitophagy flux and restored lysosomal acidification observed during cigarette smoke (CS) extract exposure in human bronchial epithelial cells, resulting in reduced cellular senescence. TFEB knockdown demonstrated involvement of pemafibrate-induced TFEB in these effects. Pemafibrate induced TFEB expression, mitigated alveolar enlargement and airflow obstruction, and attenuated the CS-induced increase in static lung compliance in a long-term CS-exposed mouse model. It reduced the CS exposure-induced cellular senescence, possibly through autophagy/mitophagy, as suggested by bulk RNA sequencing of mouse lungs. A retrospective cohort study showed that patients given pemafibrate displayed attenuated FEV1.0 decline compared with those given bezafibrate or fenofibrate. In conclusion, pemafibrate is a promising therapeutic agent for COPD, potentially exerting its effects through the regulation of the TFEB-autophagy/mitophagy-lysosome axis.

Background: Aging has a critical role in lung changes and the outcome of lung disease. Several lung aging equations have been proposed to measure deviation from physiological aging of the respiratory system. In this study, we aimed to develop a single measure of accelerated lung aging and show its application as a measure of lung aging. Method: We used a pre-bronchodilator pulmonary function test (PFT) from NHANES adult participants recruited from 2007 to 2011. We applied Klemera-Dubal Method (KDM) to four PFT measurements, FEV1, FVC, FEF25-75, and PEF, to calculate a measure of lung biological aging. Physiological Aging of the Respiratory System (PARS) was calculated from the residual method vs. chronological age. We tested the construct validity of PARS by measuring its association with risk factors of lung health. The prognostic validity was measured using a survival analysis. Sampling weights were applied to all analyses. Results: In 14,123 adult participants, the mean (SD) of accelerated lung age (PARS) was 0 (8.2) years. Participants with a history of asthma and emphysema had 4- and 10-year higher PARS. Cigarette smoking, lower socioeconomic status, black race, higher serum cadmium, and lower serum selenium and magnesium were associated with higher PARS. During 116 months of follow-up, PARS was associated with a higher mortality (HR = 1.06, 95%CI: 1.05-1.07 per year). Females with higher PARS had a higher risk of death (P for interaction < 0.001). Results were consistent across different subgroups and sensitivity analyses. Conclusion: PARS is a noninvasive lung aging marker and can be applied as a single measure of lung accelerated aging in the adult population. Its strong construct and predictive validity support its future application among different populations with and without lung disease.

Cystic fibrosis (CF) is characterized by defective CFTR-mediated chloride transport, resulting in elevated sweat chloride concentrations. As people with CF (PwCF) now live longer due to highly effective CFTR modulators, exercise has become integral to maintaining health, yet it introduces additional physiological demands on salt and fluid balance. In this study, we used a wearable microfluidic biosensor (CF Patch) to quantify sweat rate and chloride loss during exercise performed both in the supervised laboratory and remote free-living in PwCF and healthy volunteers (HV). Participants completed exercise sessions under both conditions, with continuous heart rate monitoring and sweat collection with real-time measurement of sweat characteristics. Sweat volume and chloride concentration were assessed by colorimetric image analysis, enabling estimation of total fluid and chloride loss at the end of each exercise session. PwCF exercised for a longer duration at a lower average heart rate during remote exercise compared to laboratory exercise though exercise volume (average heart rate x duration) was greater during remote exercise. There was a positive association between exercise volume and both fluid and chloride loss for both PwCF and HV. PwCF exhibited greater chloride loss for a given exercise volume compared to HV, though fluid loss was similar. Further, compared to HV, PwCF demonstrated significantly greater intra- and interindividual variability in sweat chloride loss across the remote exercise sessions. Collectively, these findings provide evidence for the feasibility and physiological validity of remote exercise assessment and establish the feasibility and physiological validity of wearable sweat sensing for remote monitoring of fluid and electrolyte dynamics during real-world exercise. In addition, the variability of chloride loss in response to exercise suggests utility of the CF Patch in providing personalized fluid and salt repletion data for PwCF and advances the translational potential of digital sweat diagnostics for personalized CF care.

Abstract Introduction Postal sputum sampling represents a potential strategy for patient-led, efficient, and regular sampling, yet little is known about the validity of posting samples for clinical and research purposes in bronchiectasis. This study aimed to validate postal sputum sampling for clinical and research applications in chronic P. aeruginosa infection. Methods Sputum was collected from 12 participants with bronchiectasis and known P. aeruginosa infection. Each sputum sample was divided into four aliquots: two were sent immediately for analysis with or without DNA-Shield (shield-fresh and non-shield-Fresh), while two were transported through the UK postal service, with or without DNA-Shield (shield-posted and non-shield-posted). All aliquots were sent at ambient temperature and subsequently processed for bacterial enumeration through selective culture, detailed antimicrobial susceptibility testing, quantitative PCR (qPCR), 16S microbiome sequencing, metabolomics, and proteomics. Results During postage, there was a median of four days (range, 2-7) between sample collection and processing. 7/12 patients were positive for P. aeruginosa by culture of fresh samples, with 100% agreement in posted samples. Postage did not affect cultured (p=0.81) or amplified load of P. aeruginosa (p=0.94), and no differences were observed in AST profiles across 140 isolates for P. aeruginosa cultured from fresh or posted samples. Metabolomics and proteomics revealed that variation between individuals was significantly greater than between fresh and posted samples, and no significant differences in microbial taxa were observed between samples. No differences were associated with the addition of DNA Shield by qPCR (p=0.19), however, freeze-thaw from -80{degrees}C increased amplified load (p=<0.01). Conclusions We found little evidence of an effect of postage on sputum positivity, recoverable load, AST profile, microbiome, proteome or metabolome in sputum samples. These data suggest postal sputum samples may be a valuable tool for clinical and research applications.

Background: Randomized controlled trials have shown that computed tomographic (CT) screening reduces lung cancer mortality. Improved identification of at-risk groups, by leveraging non-smoking risk factors, could help refine screening selection. Aim: To evaluate polygenic risk scores (PRSs) and ambient air pollution (AAP) exposure for risk stratification in the NELSON lung cancer screening cohort. Methods: Two PRSs (PRS-McKay/PRS-Byun) and several AAPs (including nitrogen dioxide, ozone, and particulate matter [PM]) were assessed in the NELSON lung cancer screening trial (N=7,364). PRSs were validated in the Rotterdam Study (N=11,493). Associations with lung cancer, mortality, screening results, and discriminative ability to distinguish lung cancer were evaluated. Results: PRS-McKay and PRS-Byun were associated with lung cancer (odds ratio [OR] per SD [95%CI]: 1.22 [1.08-1.37] and 1.28 [1.13-1.44], respectively) and lung cancer-specific mortality (OR [95%CI]: 1.24 [1.05-1.47], for both), but not with non-lung cancer mortality (OR [95%CI]: 1.01 [0.94-1.10] and 1.03 [0.95-1.12], respectively). Exposure to PM2.5 was associated with lung cancer (OR [95%CI]: 1.11 [1.01-1.22]). PM constituents were associated with adenocarcinoma, particularly PM10 (OR [95%CI]: 1.16 [1.01-1.32]) and ultra-fine particles (OR [95%CI]: 1.16 [1.04-1.30]). PRS and AAP added modestly to the discriminative ability for lung cancer on top of pack-years, age, and sex (area under the curve [95%CI]: 0.659 [0.624-0.695] vs. 0.643 [0.608-0.679]). Conclusions: PRSs and exposure to PM were associated with lung cancer in a high-risk screening population. The primary potential of PRSs may reside in refining lung cancer screening selection toward individuals at higher risk of dying from lung cancer specifically.

Objective: To evaluate the efficacy, engagement, and usability of Tune Out, an unguided, self-paced online tinnitus management program, for reducing tinnitus severity in adults with tinnitus. Design: A two-arm, parallel-group randomised controlled trial was conducted with Australian adults reporting diagnosed or self-reported tinnitus. Participants were randomised to immediate access to Tune Out or a waitlist control group. Outcomes were assessed at baseline, 6 weeks, and 12 weeks. The primary outcome was tinnitus severity measured using the Tinnitus Functional Index (TFI). Secondary outcomes included tinnitus handicap, psychological symptoms, program engagement, self-efficacy, and usability. Results: Eighty-eight participants were randomised: 43 to the intervention group and 45 to the waitlist control group. The primary outcome analysis included 63 participants at 12 weeks. A significant Group x Time interaction was observed for TFI total score, indicating greater reductions in tinnitus severity over time in the intervention group compared with waitlist control, F(2, 102.57) = 5.95, p = .004, partial 2= .104. Significant effects were also observed for tinnitus handicap, F(2, 106.76) = 4.12, p = .019, partial 2 = .072. Effects on psychological symptoms were less consistent, although anxiety showed a significant Group x Time interaction, F(2, 116.85) = 3.63, p = .030, partial 2 = .059. At 12 weeks, 23.1% of intervention participants achieved a clinically meaningful reduction in tinnitus severity compared with 5.4% of controls. Program use was highly variable, with a median use of 1.10 hours, and 25.6% of intervention participants recording no use. Usability ratings were favourable among respondents, with a mean System Usability Scale score of 73.13. Conclusions: Tune Out demonstrated preliminary efficacy for reducing tinnitus severity and tinnitus handicap compared with waitlist control. Effects on broader psychological symptoms were less consistent. Although usability was rated positively, low and variable engagement highlights the need for strategies to support uptake and sustained use in unguided digital tinnitus interventions.