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.

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.

Background: Obesity is associated with airway disease, but the contribution of specific thoracic adipose depots remains unclear. We examined whether intrathoracic adipose tissue (ITAT), defined as adipose tissue within the thoracic cavity excluding pericardial adipose tissue (PAT), was associated with airway phenotypes. Methods: We included Framingham Heart Study participants with CT-derived thoracic adipose tissue measures. Cross-sectional associations of ITAT with CT-based airway wall and lumen measurements, spirometry, and respiratory symptoms were evaluated using multivariable regression. Primary analyses used sex-specific ITAT z-scores and adjusted for waist circumference to account for central obesity. Secondary analyses examined sex-specific ITAT quintiles and compared ITAT and PAT in individual-depot and mutually adjusted models. Results: Among 2,825 adult participants (52.0% female), after adjustment for waist circumference, each 1-SD higher ITAT, relative to the sex-specific distribution, was associated with greater segmental ({beta} [95% CI]: 0.010 mm [0.006, 0.014]) and subsegmental airway wall thickness (0.006 mm [0.002, 0.009]), narrower segmental airway lumen diameter (-0.049 [-0.088, -0.011]), lower FEV1 percent predicted (-1.92 percentage points [-2.72, -1.12]), and higher odds of wheezing (OR [95% CI]: 1.16 [1.02, 1.31]) and dyspnea (1.22 [1.05, 1.42]). Associations were similar after further adjustment for PAT and across ITAT quintiles. In contrast, PAT was not independently associated with airway structural measures after adjustment for ITAT. Conclusion: Higher ITAT volume was associated with greater airway wall thickness and narrower airway lumen, as well as lower FEV1 and greater respiratory symptoms, independent of central obesity and pericardial adiposity. These findings support a depot-specific association of ITAT with airway disease.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by airway remodeling, which may extend to the central airways and alter tracheal morphology. Whether tracheal shape relates to disease severity, quality of life, functional capacity, or survival is not established. Objective: To determine whether CT-derived tracheal lumen eccentricity is associated with cross-sectional and longitudinal clinical outcomes in COPD. Methods: We analyzed 8,383 participants from the multicenter COPDGene study. At each axial cross-section of the trachea, lumen eccentricity ({epsilon}) was computed from the major and minor axis lengths, and the participant-level value was taken as the arithmetic mean across all tracheal slices; {epsilon} = 0 denotes a circular lumen and values approaching 1 denote progressively elongated ellipses. Baseline outcomes were spirometry, 6-minute walk distance (6MWD), St. George's Respiratory Questionnaire (SGRQ) total score, and modified Medical Research Council (mMRC) dyspnea score. Longitudinal outcomes were annualized change in FEV1 and all-cause mortality. Multivariable linear and Cox proportional hazards models were adjusted for [age, sex, race, BMI, smoking status, pack-years, scanner model]. Results: Tracheal eccentricity rose monotonically with severity of airflow obstruction (0.60{+/-}0.07, 0.61{+/-}0.07, 0.62{+/-}0.07, 0.64{+/-}0.08, and 0.64{+/-}0.08 in GOLD stages 0 through 4, respectively). Higher eccentricity was independently associated with lower FEV1 ({beta} = -0.30 L, 95% CI -0.47 to -0.14; p < 0.001), lower FEV1/FVC ({beta} = -0.06, 95% CI -0.09 to -0.04; p < 0.001), shorter 6MWD ({beta} = -15.7 m, 95% CI -25.2 to -6.2; p = 0.001), higher SGRQ score ({beta} = 16.9, 95% CI 11.2 to 22.5; p < 0.001), higher mMRC dyspnea score ({beta} = 0.4, 95% CI 0.1 to 0.6; p = 0.007), and accelerated lung function decline ({beta} = -23.8 mL/year, 95% CI -45.13 to -2.48; p = 0.029). Eccentricity was also associated with all-cause mortality (adjusted HR 1.81, 95% CI 1.01 to 3.26; p = 0.047). Conclusions: Tracheal lumen eccentricity is associated with worse quality of life, reduced functional capacity, accelerated lung function decline, and mortality in COPD, supporting central airway morphology as a candidate imaging biomarker.

Introduction: Persistent post-infectious olfactory dysfunction (PIOD) has limited effective treatments. In developing a randomized controlled trial (RCT) to evaluate a novel surgical intervention for persistent PIOD, embedding Patient and Public Involvement (PPI), a core NIHR requirement in research, was essential. Objectives: To outline the PPI programme for our proposed RCT, in line with UK Standards for Public Involvement. The objective of the PPI programme was to design a patient-centred, inclusive, and ethically sound trial. Methods: The PPI programme included an online survey, online discussion forums, and focus groups. Results: 63 survey responses, 2 online discussion forums, and 2 focus groups provided PPI input on control arm acceptability, participant recruitment and retention strategies, participation burden, and trial outcome selection, directly shaping the trial protocol. Conclusions: This study demonstrates how robust PPI in trial design ensures that clinical trials remain responsive to the true priorities of the patient by aligning scientific rigor with lived experience.

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.

Lung volume reduction is a treatment for chronic obstructive pulmonary disease (COPD) patients with severe emphysema. Currently, in vivo animal models are used as a first step to quantify the efficiency of novel lung volume reduction treatments. By quantifying lung volume reduction in ex vivo samples, animal testing may be reduced. This study proposes two new methods for quantifying lung volume reduction in ex vivo tissue: water displacement and three-dimensional (3D) scanning. Porcine lung lobes were inflated and treated with cyanoacrylate glue to simulate lung volume reduction. Volume changes were measured using a custom water displacement setup and in a ventilated setting using a handheld Artec Space Spider 3D surface scanner. Both techniques detected post-treatment volume reductions. Water displacement offers a simple, cost-effective approach for isolated lung lobes, while 3D scanning enables volumetric analysis of intact lungs under ventilated conditions. These methods provide a reliable intermediate step between in vitro and in vivo testing, reducing animal use and improving preclinical assessment of novel lung volume altering interventions.

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.

Study Question. COPD exacerbations with respiratory failure have an outsized impact on morbidity, mortality, and healthcare costs. Physicians treat these severe events with high doses of corticosteroids out of concern for intrinsic corticosteroid resistance. This study was designed to determine whether people who suffer from exacerbations with respiratory failure have intrinsic steroid resistance that could affect that decision. Patients and Methods. A matched, case-control study was performed at University of Colorado. Subjects were enrolled into the Exacerbation group if they were hospitalized for an exacerbation requiring ventilation, or into the Stable COPD group if they had no inpatient exacerbation within 12 months. Stable COPD subjects were frequency-matched to Exacerbation subjects for age, smoking status and FEV1%. Corticosteroid sensitivity was assessed ex vivo and in vivo >45 days following the last exacerbation during a period of relative quiescence. The primary outcome was the group difference in methylprednisolone IC50 for LPS-stimulated IL-8 release by mononuclear cells. Measurements and Main Results. The Exacerbation group (N=8) had more exacerbations in the prior year (6.0 vs. 0.5; p<0.01) and had higher baseline blood lymphocytes (p<0.01) versus Stable controls (N=8). Ex vivo, methylprednisolone equally suppressed IL-8, IL-6, TNFalpha and IL-1bets release by mononuclear cells and whole blood across groups. In vivo, methylprednisolone decreased plasma mediators and mononuclear cells in both groups but had a small differential effect on mononuclear cell gene expression. Answer to the Question. Exacerbations with respiratory failure have persistent lymphocytosis, an altered gene response to corticosteroids, but no corticosteroid resistance to suppress inflammation.

Objectives: To investigate whether the PneumoRator wearable sensor could accurately assess Respiratory Rate (RR) and signs of air hunger (SAH) compared with clinician-observed assessment in adults with and without breathing pattern disorder (BrPD). Design: A pilot cross-sectional observational study. Setting: A research laboratory on a university campus. Participants: Healthy adults aged 18-40, who were not pregnant, no smokers or history of cardiovascular, respiratory or neurological illness. Thirty consented to the study, Twenty-nine had full data for analysis. Interventions: Participants wore the PneumoRator chest-worn sensor continuously for 10 minutes while seated at rest. Main outcome measures: Respiratory Rate was compared between PneumoRator-derived measurements and randomised 1-minute observer manual counts. Clinician-observed SAH and BrPD were assessed using the Breathing Pattern Assessment Tool (BPAT). Participants also completed the Nijmegen Questionnaire. PneumoRator signals were analysed to identify large-volume breaths as potential SAH events. Results: Thirty participants were recruited. Twelve participants met BPAT criteria for BrPD and four met Nijmegen Questionnaire criteria. There was no significant difference between manual and PneumoRator RR measurements (p=0.89). No significant difference was observed between methods for SAH detection (p=0.17). Participants with clinician-observed SAH demonstrated significantly higher PneumoRator signal amplitudes than those without SAH (p=0.035). Conclusion: The PneumoRator produced RR measurements comparable to clinician assessment and demonstrated potential for identifying signs of air hunger. Findings from this pilot study indicate that the PneumoRator device shows promise as a tool for continuous RR monitoring and as an adjunct to BrPD assessment. Larger clinical validation studies are now warranted.

Background. Sarcopenia is common in chronic obstructive pulmonary disease (COPD) and contributes to adverse outcomes. Alpha-1 antitrypsin deficiency (AATD) is the most common genetic cause of COPD, but its impact on skeletal muscle remains to be determined. Methods. We performed a retrospective analysis of 487,207 participants in the UK Biobank with available SERPINA1 genotyping. Associations between AAT genotypes and measures of skeletal muscle mass were determined using multivariable linear and logistic regression models. Models adjusted for age, sex, smoking status, genetic principal components, lung function (FEV% predicted), and liver fibrosis risk (FIB-4). We determined that the Z-allele was associated with sarcopenia and mortality using regression models and mediation analysis. Results. Compared with PI*MM individuals, carriers of the Z allele (PI*MZ, PI*SZ, PI*ZZ) demonstrated significantly lower fat free mass index (FFMI) and appendicular skeletal muscle index (ASMI), as well as higher odds of sarcopenia by binary definition. Associations persisted after adjustment for lung and liver function. A dose-dependent relationship was observed, with the greatest reductions in muscle mass and highest sarcopenia associated with PI*ZZ individuals (adjusted OR for FFMI-defined sarcopenia 2.02, 95% CI 1.16-3.32). Each additional Z allele was associated with increased mortality risk (adjusted OR 1.09, 95% CI 1.02-1.16), with sarcopenia mediating a modest proportion (~2.6%) of this association. Conclusions. The SERPINA1 Z allele is associated with reduced muscle mass and increased risk for sarcopenia independent of lung and liver disease. Our findings expand the phenotypic spectrum of AATD-related diseases to include skeletal muscle as a modifiable target for intervention.

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.

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: Acute pulmonary embolism (PE) is a major cause of cardiovascular morbidity and mortality. This study aims to describe the epidemiological trends, clinical complexity, and in-hospital mortality of PE admissions in Spain from 2022 to 2024. Methods: We conducted a nationwide, retrospective study using the Spanish Minimum Basic Data Set for Hospitalization (MBDS-H) for adult patients admitted with acute PE. Results: We identified 125,305 hospital admissions for acute PE. The median patient age was 74 years with a slight male predominance (51-52%). A high comorbidity burden was observed: 61-62% had COPD, 35-37% hypertension, and 21-24% malignancy; ICU admissions increased from 11% to 13% (p < 0.001), with median ICU stay rising from 4 to 7 days (p < 0.001). In-hospital mortality significantly decreased during 2022-2024 from 13.12% to 11.44% (p = 0.013). Mortality per 100,000 inhabitants was consistently higher in men. Conclusion: This study highlights the high healthcare burden posed by acute embolism in hospitals, demonstrating an increase in patient complexity alongside a decline in overall mortality.

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.

IMPORTANCE: CD4+ T helper (T) 1, T2 and T17 cells have helped identify asthma endotypes in predominantly non-Hispanic White adults. Identifying asthma endotypes in diverse subgroups should help develop personalized medicine in asthma. OBJECTIVE: To characterize asthma endotypes and their association with selected variables and asthma severity/control in adults. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional and longitudinal analyses of nasal samples from the SOL-Asthma study of Puerto Rican and Dominican adults with (cases, n=313) and without (controls, n=371) asthma in the Bronx (NY) and Chicago (IL), with replication of selected findings in 376 adults of African ancestry in CAAPA. MAIN OUTCOMES AND MEASURES: Our primary outcome was asthma endotypes identified through nasal expression of "signature genes" for 3 T2, 5 T1, and 5 T17 pathways. Multinomial logistic regression was used for the analysis of asthma endotypes (with controls as the reference outcome category) at a baseline visit, as well as for the analysis of severe asthma exacerbations (SAEs) at baseline and during a 1-year follow-up. We attempted to replicate the identified profiles in CAAPA. RESULTS: In SOL-Asthma, cases were more likely to be female, Puerto Rican, and current/former smokers, and to have physician-diagnosed COPD than controls. Five transcriptomic profiles were identified in cases: T2HIGH (n=16 [5.1%]), T1HIGH (n=71 [22.7%]), T17HIGH (n=96 [30.7%]), T1HIGH/T17HIGH (n=53 [16.9%]), and T2LOW/T1LOW/T17LOW (n=77 [24.6%]). In a multivariable analysis, Puerto Ricans were more likely to have a T17HIGH profile than Dominicans (odds ratio [OR]=2.48, 95% confidence interval [CI]=1.08-5.74) and female sex was associated with T1HIGH (OR=3.44, 95% CI=1.33-8.88), T1HIGH/T17HIGH and T2LOW/T1LOW/T17LOW profiles, while COPD was associated with profiles other than T2HIGH or T1HIGH. The T1HIGH profile was associated with [&ge;]1 SAE in the year prior to baseline and during the one-year follow-up (OR=4.31, 95% CI=1.26-14.77). Each profile had unique differentially expressed genes (DEGs), with substantial replication of the profile distribution and DEGs in CAAPA. CONCLUSIONS AND RELEVANCE: Nasal transcriptomics identified profiles corresponding to five asthma endotypes in a cohort of Puerto Rican and Dominican adults. Puerto Rican background, female sex, and physician-diagnosed COPD were associated with non-T2HIGH (T2LOW) asthma endotypes, and T1HIGH asthma was strongly associated with SAEs.