American Journal of Respiratory and Critical Care Medicine

Background Chronic rhinosinusitis (CRS) and nasal polyps (NP) are closely related inflammatory airway diseases, and their co-occurrence is often associated with more persistent symptoms, frequent recurrence, and substantial respiratory morbidity. However, the extent to which CRS without and with NP (CRSsNP and CRSwNP) share genetic susceptibility-and which genetic mechanisms are disease-specific-remains poorly characterized. Methods We conducted cross-population genome-wide association meta-analyses of overall CRS (including both CRSwNP and CRSsNP) and NP (a proxy for CRSwNP) using data from six biobanks. We estimated genome-wide genetic correlations between overall CRS, CRSwNP, and a spectrum of respiratory diseases. We applied five complementary gene-prioritization strategies to nominate CRS- and CRSwNP-associated genes and performed pathway enrichment analyses to infer implicated biological processes. For CRSwNP, we integrated single-cell transcriptomic data to characterize cell-type-specific expression of prioritized genes and used stratified LD score regression to quantify heritability enrichment across immune and epithelial annotations. To delineate shared versus disease-specific genetic signals, we performed three comparative analyses-local genetic correlation, CRSwNP-CRS colocalization, and genomic structural equation modeling. Finally, we performed proteome-wide Mendelian randomization to identify circulating proteins with putative causal effects on CRS and CRSwNP. Results This GWAS meta-analysis identified 96 genome-wide significant loci for CRSwNP and 41 for overall CRS, prioritizing 92 and 39 candidate genes, respectively. CRSwNP and overall CRS showed shared genetic susceptibility (rg = 0.59; P = 6.8e-16), while CRS exhibited broader genetic correlations across multiple respiratory disorders. Pathway analyses consistently implicated immune signaling albeit with disease-specific emphases and lipid-metabolism networks. Single-cell analyses demonstrated distinct expression of CRSwNP-prioritized genes across nasal epithelial and immune cell clusters, and immune annotations explained more CRSwNP heritability (enrichment score = 4.1; P = 0.010) than epithelial annotations (2.5; P = 0.072). Comparative genetic analyses highlighted multiple shared loci-including BACH2, CD247, FADS2, FOXP1, FUT2, GPX4, IL7R, NDFIP1, RAB5B, RORA, SMAD3, TSLP - as well as 3 CRSwNP-specific and 6 CRS-specific loci. Proteome-wide MR identified 10 and 8 putatively causal circulating proteins for CRSwNP and overall CRS, respectively, with protein TNFSF11, IL2RB, and STX4 associated with both conditions. Conclusions This multi-population GWAS meta-analysis expanded genetic discovery for CRS and CRSwNP and showed substantial shared liability with distinct disease-specific components. Immune components explained a larger proportion of CRSwNP heritability than epithelial annotations, reinforcing the primacy of immune-driven mechanisms in polyp disease.

BackgroundPleuroparenchymal fibroelastosis (PPFE) is a rare, fibrotic lung disease with poor prognosis, usually affecting adults which most commonly occurs idiopathically. Biallelic pathogenic variants in DGUOK cause mitochondrial DNA (mtDNA) depletion syndrome, predominantly affecting infants with severe hepatic and neurological symptoms. Detailed description of pulmonary manifestations with late-onset presentation have not been reported. MethodsWe describe nine patients with PPFE and DGUOK-associated mitochondriopathy. Clinical, radiological, histopathological, and genetic data were systematically collected from all patients. Functional studies, single nucleus RNA sequencing (snRNAseq), immunofluorescence staining, transmission electron microscopy and respiratory chain enzyme activity assays were conducted on patient-derived fibroblasts, muscle or lung tissues. mtDNA content quantification was performed on whole genome sequencing (WGS) data. ResultsAll patients (ages 5-36) presented with progressive dyspnea, weight loss and some with spontaneous pneumothoraces. Chest computed tomography and lung biopsies showed features of PPFE. Biallelic pathogenic DGUOK variants were identified in all patients, seven of them carry an unreported intronic variant leading to mtDNA depletion. snRNAseq of lung tissue from four pediatric patients identified Aberrant Basaloid cells and intermediate cells as their precursor localized at the fibrotic edge. Mitochondrial alterations were identified by electron microscopy. ConclusionPPFE in children and young adults is associated with DGUOK-related mitochondriopathy. For the first time, we demonstrate Aberrant Basaloid cells in pediatric fibrotic lung tissue. Since pulmonary involvement may be underrecognized or misinterpreted and the clinical presentation may not always be typical of a mitochondriopathy, we recommend genetic testing in all patients with PPFE of unknown origin.

BackgroundTBX4 variants are a recognised cause of paediatric pulmonary hypertension (PH), often associated with interstitial lung disease (ILD). Evidence for ILD-directed therapy in this group is lacking. MethodsWe conducted a retrospective study of children ([≤]18 years) with TBX4-associated PH at a national centre (2001-2025). ILD was defined using ChILD-EU criteria. Patients treated with pulsed intravenous methylprednisolone were assessed for response using ChILD-EU categories. Secondary outcomes included respiratory severity score (RSS), functional class (FC), echocardiographic measures, and NT-proBNP. ResultsOf 21 children, 11 (52%) had ILD; 9 received corticosteroids. Median age at treatment was 0.8 years. A clear or best response occurred in 7/9 (78%). RSS improved in 6/9 (p=0.02), with all children on respiratory support showing partial or complete weaning. Functional class improved in all with FC III/IV at baseline (p=0.02). Right ventricular function improved (TAPSE z-score +1.65, p=0.04), and elevated NT-proBNP normalised. Key clinical milestones included ECMO weaning, transplant delisting, and discontinuation of prostacyclin therapy. No significant adverse effects were observed. Untreated children showed no early improvement. ConclusionsCorticosteroids were associated with meaningful improvements in respiratory and PH outcomes in TBX4-associated PH with ILD. Prospective evaluation is warranted.

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by aberrantly activated, apoptosis-resistant profibrotic lung (myo)fibroblasts. Prior research has demonstrated that lung fibroblasts from patients with IPF exhibit resistance to DNA damage, suggesting that this behavior contributes to their persistent survival and continuous proliferation. We propose that elevated levels of the DNA damage repair protein RAD51 regulate myofibroblast activation and apoptosis and provide a potential therapeutic target to impede fibrosis progression. MethodsHuman lung fibroblasts were transfected with siRNA against RAD51 or treated with RAD51-specific inhibitor B02 and markers of fibrosis, DNA damage, apoptosis, metabolic reprogramming, and mitochondrial dynamics were assessed. The preclinical efficacy of B02 was evaluated in human precision cut lung slices (PCLS) and in a mouse model of pulmonary fibrosis. FindingsRAD51 expression was significantly upregulated in the lungs and lung fibroblasts of IPF patients. Knockdown or inhibition of RAD51 in fibroblasts reduced profibrotic marker expression, suppressed mTORC1 signaling and mitochondrial function, and increased apoptosis susceptibility. Pharmacological inhibition of RAD51 shifted the profibrotic phenotype towards a fibrosis-resolving state in human and mouse PCLS, and in a bleomycin-induced mouse model of lung fibrosis. InterpretationThe inhibition of RAD51 exerts therapeutic benefits in lung fibrosis by promoting apoptosis. Our findings identify that inhibiting RAD51 with B02 in fibroblasts impairs DNA repair and induces metabolic reprogramming, making it a potential therapeutic target. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSPulmonary fibrosis (PF) is characterized by excessive fibroblast activation and subsequent deposition of extracellular matrix (ECM) proteins, which ultimately disrupt normal lung architecture. A significant contributing factor to the pathogenesis of pulmonary fibrosis is the presence of fibroblasts that are resistant to apoptosis, preventing normal wound healing. Recent studies highlight the DNA repair protein RAD51 as effective in protecting fibroblasts from death induced by chemotherapy and ionizing radiation. These finding suggested that RAD51 could have a role in fibroblast activation and apoptosis resistance in pulmonary fibrosis. Added value of this studyWe demonstrated that RAD51 is important for maintaining apoptosis-resistant fibrotic fibroblasts and their metabolic abnormalities. Our findings indicated that TGF{beta}-mediated upregulation of RAD51 reduces DNA damage, activates multiple pathways related to fibroblast activation and proliferation, and induces metabolic reprogramming, ultimately regulating apoptosis. Mechanistically, RAD51 inhibition enhanced p53 acetylation at lysine 120 and upregulated the expression proapoptotic proteins PUMA/BAK in mitochondria, promoting apoptosis. Pharmacological inhibition of RAD51 using the specific inhibitor B02 during the fibrotic phase of experimental lung disease effectively ameliorated pulmonary fibrosis. Implications of all the available evidenceOur findings establish that RAD51 plays an important role in the survival of apoptosis-resistant fibrotic fibroblasts. We propose that reducing RAD51 expression leads to the metabolic reprogramming of activated fibroblasts, resulting in decreased mitochondrial respiration, reduced ATP levels, and diminished glycolysis or glutaminolysis. These observations suggest that targeting energy metabolism through RAD51 inhibition could be a viable strategy to enhance apoptosis, thereby creating a therapeutically targetable pathway in fibrotic cells. These findings highlight the potential of RAD51 as a therapeutic target for the treatment of IPF.

Lung fibroblasts are key regulators of tissue homeostasis and extracellular matrix (ECM) remodeling, and their aberrant activation drives the progressive parenchymal scarring characteristic of idiopathic pulmonary fibrosis (IPF), a fatal disease with limited therapeutic options. Despite their central pathogenic role, lung fibroblasts are difficult to isolate due to their embedded position within the ECM, and standard in vitro culture conditions may lead to the loss of their native functional and transcriptional characteristics, hampering the study of fibroblast behavior in disease. The transcriptional heterogeneity of lung fibroblast subtypes and the extent to which culture-induced alterations diverge from native tissue signatures remain poorly understood. Here, we integrated single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics of lung tissue from IPF patients and age-matched healthy donors with transcriptomic profiling of cultured fibroblasts collected at passages 1 and 6 after isolation using three optimized protocols: whole lung cell suspension (WLCS), negative fraction enrichment, and outgrowth. Tissue-based analysis identified six transcriptionally distinct mesenchymal subtypes: alveolar, adventitial, inflammatory, peribronchial, CTHRC1+ and smooth muscle cell (SMC). The fibroblast subtype CTHRC1+ represented the most transcriptionally activated pro-fibrotic subtype, showing the greatest upregulation of ECM biosynthesis genes, a prominent role in intercellular communication, and preferential enrichment within fibroblastic foci in IPF lung tissue. Pseudotime trajectory analysis supported a directional transcriptional continuum from alveolar and inflammatory fibroblasts toward the CTHRC1+ state, driven by coordinated activation of pro-fibrotic transcription factors, including RUNX2, CREB3L1, and SCX. In vitro culture progressively reshaped fibroblast transcriptional identity relative to native tissue, with increased collagen and matrix metalloproteinase (MMP) expression during passaging, loss of distinct CTHRC1+ fibroblasts, and gain of alveolar fibroblasts displaying pro-fibrotic activation across all isolation protocols. These findings provide a high-resolution transcriptional map of lung fibroblast heterogeneity in IPF and highlight critical limitations of standard in vitro culture systems for recapitulating native fibroblast diversity, with important implications for the development and evaluation of fibroblast-targeted therapeutic strategies in IPF.

ObjectiveOnly preliminary investigations on the use of the 445 nanometer wavelength blue light laser (BLL) for various laryngeal pathologies have been described. Currently, no standard exists for reporting treatment technique and tissue effect with this modality. Here, we aim to establish and validate a classification system to describe laser-induced tissue effects. Study DesignRetrospective video-based study for classification development and reliability validation. MethodsVideo recordings from procedures performed with the BLL by multiple academic laryngologists were retrospectively reviewed. A preliminary 6-point classification (BLL 1-6) was developed based on expert consensus. Thirteen additional procedural clips were independently rated utilizing the classification schema to assess perceived tissue effect, and measure inter- and intra-rate reliability. ResultsThe final 5-point classification system (BLL 1-5) included angiolysis, blanching, tissue vaporization, ablation with mechanical tissue removal, and cutting. The consensus of the combined reviewers in rating all cases was 89% (58 of 65). Complete consensus was not achieved in 11% (7/65) of cases. Of those incorrect, 57% (4/7) were of clips illustrating the BLL-2 classification. Intra-rater reliability amongst the reviewers was 100%. ConclusionTissue effect of the 445 nm blue light laser can reliably be standardized with this proposed classification system. This rating system can be used to facilitate future systematic study of outcomes and effective communication between laryngologists and trainees.

Genome-wide association studies of idiopathic pulmonary fibrosis (IPF) have identified 35 common genetic risk loci associated with IPF susceptibility. In this study, we evaluated the effects of the reported variants in clinically curated non-European individuals. Despite limited sample sizes, we observed partial replication, limited transferability of some variants and evidence of ancestry-specific effects. The MUC5B promoter variant rs35705950 emerged as the dominant and most consistent signal across ancestries. Our findings highlight the need for larger, well-characterised studies in understudied populations to support robust discovery and translation.

Pulmonary fibrosis (PF) involves excessive collagen accumulation, yet mechanisms shifting the balance of synthesis and degradation toward net deposition remain unclear. Myeloperoxidase (MPO) inversely correlates with survival in PF. Using the bleomycin model, we found MPO knockout (MPOko) mice were protected from fibrosis, and pharmacological MPO inhibition after peak inflammation (day 7) recapitulated this protection. MPO persisted in lung tissue 21 days post-injury despite neutrophil efflux, linking acute inflammation to sustained remodeling. Mechanistically, we identified that MPO inhibits Cathepsin K (CatK), a potent collagenolytic enzyme involved in fibrosis resolution. Notably, CatK gene expression (CTSK) is elevated in PF, suggesting post-translational inhibition of CatK. MPOko and inhibitor-treated mice exhibited elevated CatK activity after bleomycin; exogenous addition of pathophysiologic concentrations of MPO reduced CatK activity in mouse precision-cut lung slices and human fibroblasts. Biochemically, MPO reduced CatK activity to 33% of control. In two distinct cohorts of PF patients, we observed significantly increased MPO protein levels in platelet poor plasma and in lung tissue. In PF patients, 62% had MPO levels in platelet poor plasma exceeding healthy controls, while lung tissue from other PF patients showed significantly elevated MPO staining. Plasma levels were inversely correlated with decreased survival, FVC, and DLCO. These findings establish MPO as a post-translational inhibitor of CatK-mediated collagenolysis, revealing a mechanism linking acute inflammation to sustained fibrosis and suggest a patient subpopulation that may benefit from MPO-targeted therapy. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=54 SRC="FIGDIR/small/713467v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@d8fc5eorg.highwire.dtl.DTLVardef@1a088fcorg.highwire.dtl.DTLVardef@818b7dorg.highwire.dtl.DTLVardef@ecdca0_HPS_FORMAT_FIGEXP M_FIG C_FIG Myeloperoxidase persists in lung tissue after injury and inhibits cathepsin K activity, impairing collagen degradation and promoting extracellular matrix accumulation during pulmonary fibrosis.

RationaleBronchopulmonary dysplasia (BPD), the lung disease associated with premature birth, is a significant health problem, often with long-term respiratory consequences. Recent research has highlighted the potential role of the lung and gut microbiome in the development and progression of BPD, yet it is unclear what aspects of the microbiome may contribute to BPD susceptibility. ObjectivesTo comprehensively characterize the lung and gut microbiomes of preterm infants and identify shared microbial taxa that are associated with BPD development. MethodsTracheal aspirate and stool samples were collected from 39 premature infants over the first month of life. To assess the taxonomic microbial composition of the lung and gut, samples were analyzed using shotgun metagenomic sequencing. BPD classification was determined using the National Institute of Child Health and Human Development severity-based definition at 36 weeks postmenstrual age. Measurements and Main ResultsMicrobial communities of the lung and gut were significantly different between infants who went on to develop BPD and those who did not, with an enrichment of skin-associated microbial genera such as Staphylococcus, Corynebacterium, and Cutibacterium in infants who developed BPD. Specifically, Staphylococcus epidermidis was enriched in premature infants who developed BPD and was the most prominent species shared between lung and gut communities. Temporal changes in gut microbial communities co-occurred with feeding practices and antibiotic exposure, suggesting an influence of external factors on microbiome composition. ConclusionsOur findings provide evidence that certain microbial colonization patterns among premature infants are closely associated with the pathogenesis and progression of BPD.

Resolution of fibrosis following lung injury is distinguished from persistent/progressive parenchymal scarring through the timely clearance of aberrant cell types, removal of excess collagens, and regeneration of alveolar structure. The requisite signaling pathways, cellular cross-talk, and phenotypic shifts associated with, and required for, resolution of established lung fibrosis have not been well characterized. To address this critical knowledge gap, we performed longitudinal single-cell RNA sequencing of whole mouse lung digests obtained during spontaneously resolving fibrosis. We observed a putatively pro-fibrotic macrophage population emerge during peak fibrosis and undergo partial clearance during resolution. Our study also revealed conspicuous shifts in well-established pathways associated with tissue repair and fibrosis among immune, mesenchymal, and epithelial cells during spontaneous resolution. In addition to a decline in pro-fibrotic driver pathways, the putative anti-fibrotic pathways cAMP, HGF/MET, and TWEAK were enriched in several cell types during spontaneous resolution. CellChat analysis was used to predict the cellular senders and recipients of each pathway and characterize their longitudinal changes. Our characterization of the cellular and molecular dynamics in whole lungs during spontaneous fibrosis resolution provides a foundation for the identification of endogenous pathways that might be leveraged to treat pulmonary fibrosis.

Background Acute respiratory distress syndrome (ARDS) is characterised by substantial physiological heterogeneity, which contribute to a very variable clinical outcomes and therefore inconsistent responses to ventilatory strategies. We aimed to externally validate physiological ARDS subphenotypes previously identified using routine ventilatory and gas-exchange variables, assess their prognostic relevance across independent cohorts, and examine heterogeneity of treatment effect according to PEEP strategy. Methods Unsupervised Gaussian Mixture Modelling was used to identify physiological subphenotypes based on ventilatory mechanics and gas-exchange parameters. Labels were subsequently used to train and validate supervised classifiers using XGBoost. Prognostic relevance was assessed across three independent cohorts, including two randomised controlled trials (ALVEOLI and LOVS). Predictive enrichment for PEEP strategy was evaluated using individual patient data from ALVEOLI and LOVS (n = 1,532) using intention-to-treat analyses, applying both one-stage and two-stage fixed-effects IPD meta-analytic approaches to test for interaction between physiological subphenotype and PEEP strategy. Results Two distinct physiological subphenotypes, termed Efficient and Restrictive, were replicated across independent cohorts. Across each cohort, patients classified as Restrictive consistently exhibited higher all-cause 28-day mortality compared to Efficient patients. When pooled across studies, the Restrictive subphenotype was associated with a significantly increased risk of death (pooled odds ratio 1.75, 95% CI 1.36-2.24), with no evidence of between-study heterogeneity. Predictive analyses showed a statistically significant interaction between physiological subphenotype and PEEP strategy in the one-stage IPD model (p for interaction = 0.037), with concordant findings in the two-stage fixed-effects IPD meta-analysis (interaction OR 1.91, 95% CI 1.00-3.66; I2 = 0%). Higher PEEP was associated with increased mortality in Efficient patients and reduced mortality in Restrictive patients, indicating effect modification by physiological subphenotype. Interpretation Physiological ARDS subphenotypes derived from routinely collected bedside data provide robust and externally validated prognostic stratification across observational and randomised trial cohorts. The observed interaction with PEEP strategy suggests that underlying physiological profiles may influence treatment response, supporting the concept that physiology-based be a starting point for personalized medicine and therefore better ventilatory strategies in future clinical trials.

BackgroundLung ischemia-reperfusion (IR) injury drives early morbidity after lung transplantation and cardiothoracic surgery, yet targeted preventive therapies are lacking. The gut-lung axis and microbiota-derived tryptophan metabolites, including indole-3-propionate (IPA), may regulate pulmonary immunity and inflammation. We investigated whether a tryptophan-rich (Trp-Rich) diet attenuates sterile lung IR injury by increasing microbiota-derived indole metabolites and reprogramming alveolar macrophage (AM) inflammatory responses. MethodsC57BL/6 mice received isocaloric tryptophan-standard (Trp-Std; 0.18%) or Trp-Rich (0.60%) diets for 14 days, then underwent unilateral left lung IR (60 min ischemia followed by 60 min reperfusion). Oxygen saturation, lung cytokines, and aryl hydrocarbon receptor (AhR) signaling readouts (Cyp1a1/Cyp1b1) were evaluated. Gut microbiota was profiled by 16S rRNA sequencing, and targeted metabolomics quantified tryptophan metabolites in feces, portal vein (PV) plasma, and lung tissue. To further assess inflammatory priming in vivo, mice were additionally challenged with intratracheal lipopolysaccharide (LPS). Mechanistic studies compared IPA with related indole metabolites in MH-S cells and primary human AMs, including ex vivo nutritional IR, LPS stimulation, and AhR stimulation and blockade using synthetic agonists and antagonists. ResultsTrp-Rich feeding improved post-IR oxygenation, reduced lung IL-1{beta}, and increased pulmonary Cyp1a1/Cyp1b1 gene expression. Trp-Rich diet remodeled the gut microbiota, including enrichment of Bifidobacterium and Lactobacillus, and increased IPA levels across feces, PV plasma, and lung tissue, with lower kynurenine/IPA ratios across matrices. In the LPS intratracheal challenge, Trp-Rich feeding reduced IL-6 levels in lung tissue and systemic plasma. Primary murine AMs isolated from Trp-Rich mice also showed reduced IL-1{beta} and IL-6 release in an ex vivo nutritional IR model. Among tested indole metabolites, IPA showed the strongest dose-dependent suppression of LPS-induced cytokines and chemokines in MH-S cells and primary human AMs, remained active in the ex vivo nutritional IR model, and its anti-inflammatory effect was abrogated by AhR blockade and enhanced by co-treatment with other indole metabolites. ConclusionsA Trp-Rich diet attenuated sterile lung IR injury, coinciding with gut microbiota remodeling, increased systemic and pulmonary IPA, reduced inflammatory priming, and reprogrammed AM responses. These data support diet- or microbiome-directed strategies targeting IPA-AhR signaling to mitigate perioperative lung IR injury. Caption for graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=190 SRC="FIGDIR/small/714281v1_ufig1.gif" ALT="Figure 1"> View larger version (67K): org.highwire.dtl.DTLVardef@1b06a9corg.highwire.dtl.DTLVardef@1273f33org.highwire.dtl.DTLVardef@1a63a2borg.highwire.dtl.DTLVardef@350e1c_HPS_FORMAT_FIGEXP M_FIG A tryptophan-rich diet remodels the gut microbiota and indole metabolite profiles, including IPA, enhances alveolar macrophage AhR signaling, and attenuates sterile lung ischemia-reperfusion injury. C_FIG

Background: We aimed to identify data-driven FEV1 trajectory phenotypes post-chronic lung allograft dysfunction (CLAD), relate these phenotypes to patient factors and future graft loss, and develop a classification approach for prospective patients. Methods: We studied adult first lung recipients with probable CLAD from two prospective multicenter cohorts: CTOT-20 (n=206) and LTOG (n=1418). FEV1 trajectories over the first nine months post-CLAD were characterized using joint latent class mixed models, jointly modelling time-to-graft loss to account for informative censoring. Models were fit independently in both cohorts and also only among LTOG bilateral recipients. A classification and regression tree (CART) model was derived in LTOG bilateral recipients and applied to CTOT-20 bilateral recipients. Findings: Four distinct early FEV1 trajectory classes were identified in CTOT-20, with large differences in nine month graft loss (72.3%, 31.1%, 2.2%, 0%). In LTOG, similar trajectory patterns were reproduced, with an additional class demonstrating early post-CLAD FEV1 improvement. Among bilateral recipients, trajectory classes showed a clear risk gradient, including a high-risk class with 100% graft loss and a low-risk class with no early graft loss. A CART model incorporating clinical and spirometric variables demonstrated good discrimination in LTOG bilateral recipients (multiclass AUC 0.85) and consistent class assignment and trajectory patterns when applied to CTOT-20. Interpretation: We identified reproducible, clinically meaningful early post-CLAD FEV1 trajectory phenotypes with differential graft loss risk. These phenotypes and a pragmatic classification tool may support risk stratification, trial enrichment, and improved prognostication for patients and clinicians.

Background: Idiopathic pulmonary fibrosis (IPF) is a rare disease with a poor prognosis. Disease risk involves rare and common genetic variants. However, an inverse association have been described between them. Accordingly, IPF patients with a higher polygenic risk score (PRS) for IPF are less likely to carry rare deleterious variants and vice versa. Here, we evaluate weather PRS of IPF could serve as an additional criterion to patient prioritisation for rare variant discovery. Methods: We identified carriers based on the presence of rare qualifying variants (QVs) in genes linked to monogenic forms of pulmonary fibrosis in 888 IPF patients from the Pulmonary Fibrosis Foundation Patient Registry (PFF-PR). Genome-wide association study (GWAS) summary statistics from independent cohorts were used to construct a whole-genome PRS (WG-PRS) using a clumping and thresholding method (C+T) and a Bayesian method (SBayesRC). PRS were also derived from 19 known common sentinel IPF variants (Sentinel-PRS). Logistic regression models were used to evaluate associations between PRS and carrier status. Discriminatory performance was evaluated using area under the curve (AUC) analysis, and comparisons were made with DeLong test. Validation was performed in 472 IPF individuals from the UK PROFILE cohort. Results: IPF-PRS were strongly associated with the QVs carrier status: Odds Ratio [OR] 0.65 (95% Confidence Interval [CI] 0.53-0.79) for WG-PRSC+T, OR 0.71 (95% CI 0.59-0.86) for WG-PRSSBayesRC, and OR 0.77 (95% CI 0.63-0.94) for Sentinel-PRS. Adding WG-PRS to the patient personal clinical history improved the prediction of QVs carriers: AUC=0.62 for the clinical model, AUC=0.68 for WG-PRSC+T (DeLong test, p=9.54x10-4) and AUC=0.66 for WG-PRSSBayesRC (DeLong test, p=0.02). Adding of IPF-PRS to clinical variables correctly reclassified 22.8% of carriers when using WG-PRSC+T, 20.8% when using Sentinel-PRS, and 16.7% for WG-PRSSBayesRC. WG-PRSSBayesRC and the Sentinel-PRS also demonstrated improved prediction of QVs carriers in telomere-related genes in PROFILE. Conclusions: Incorporating IPF-PRS into a model based on the patient clinical history improves the identification of QVs carriers. Although the overall discriminatory power was moderate, these findings raise de the possibility of using WG-PRS as useful criterion for rare variant discovery in patients with IPF and enhance decision-making.

Background: Our group previously reported that lung cancer (LC) screening history results and subsequent timing of diagnosis are associated with significant differences in survival outcomes. As a follow-up study, we sought to develop novel personalized risk models that considered screening history for incidence cancers, interval LCs, and prevalence LCs. Methods: Using data from the CT-arm of the NLST, four independent case-control analyses were conducted to develop parsimonious risk models. Controls (n=26,038) were those never diagnosed with LC. The four LC case groups were 270 prevalence LCs, 44 interval LCs, 206 screen-detected LCs (SDLCs) that had a baseline positive screen, and 164 SDLCs that had a baseline negative screen. For each case-control analysis, univariable analyses identified statistically significant covariates from 48 variables and then significant covariates were included into a stepwise backward selection approach to identify a model with the most informative covariates. Results: For prevalence LCs, the model (AUC=0.711) included age, pack-years smoked, BMI, smoking status, smoking onset age, personal history of cancer, family history of LC, alcohol consumption, and milling occupation. For interval LCs, the model (AUC=0.734) included age, smoking status, smoking onset age, cigar smoking, marital status, and asbestos occupation. For baseline positive SDLCs, the model (AUC=0.685) included age, pack-years smoked, BMI, emphysema, chemicals/plastics exposure, and milling occupation. For baseline negative SDLCs, the model (AUC=0.701) included age, pack-years smoked, BMI, smoking status, emphysema, sarcoidosis, and sandblasting occupation. Conclusions: Besides smoking and age, which are inclusion criteria for screening, these models identified other important risk factors which could be used to provide personalized LC risk assessment and screening management.

Purpose: To evaluate whether chest radiograph-derived age acceleration is associated with incident lung cancer and whether it improves discrimination beyond established lung cancer risk factors. Materials and Methods: This retrospective analysis used prospectively collected data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Baseline digitized chest radiographs from the initial screening year were analyzed using a previously validated deep learning model that estimates chest radiograph-derived age (Xp-age). Age acceleration (AgeAccel) was defined as the residual of Xp-age after calibration to chronological age using a regression model from the development dataset. A 1-year landmark design excluded participants diagnosed with lung cancer or censored within 1 year of baseline. Associations with incident lung cancer were assessed using multivariable Cox proportional-hazards models adjusted for prespecified demographic and clinical predictors, including smoking variables used in the PLCOm2012 risk prediction model. Discrimination was evaluated using the concordance index and 6-year time-dependent area under the receiver-operating-characteristic curve. Results: The analytic cohort included 23,213 participants (mean age, 62.5 years); 790 developed incident lung cancer after the landmark (mean follow-up, 16.7 years). Higher AgeAccel was associated with increased lung cancer incidence (hazard ratio, 1.10 per 1-SD increase; 95% confidence interval: 1.03- 1.17); however, addition of AgeAccel to an established risk factor model resulted in minimal change in discrimination (C-index, 0.840 vs. 0.839; time-dependent AUC at 6 years, 0.852 vs. 0.852). Attribution maps emphasized the aortic arch/mediastinal region with similar spatial patterns across smoking and lung cancer strata. Conclusion: Chest radiograph-derived age acceleration was independently associated with future lung cancer incidence.

BackgroundWe explored the efficacy of AS01E-adjuvanted respiratory syncytial virus prefusion F protein-based vaccine (adjuvanted RSVPreF3) in subpopulations of participants with underlying medical conditions in the multi-country, phase 3 AReSVi-006 trial (conducted May/2021-May/2024). MethodsMedically stable [≥]60-year-olds were 1:1-randomised to receive one adjuvanted RSVPreF3 or placebo dose pre-RSV season 1. In exploratory post-hoc analyses in subgroups of participants with underlying conditions (including COPD, asthma, diabetes, obesity [BMI[≥]30 kg/m2]), we evaluated efficacy of one vaccine dose against RSV-related lower respiratory tract disease (RSV-LRTD), acute respiratory illness (RSV-ARI), and RSV-ARI-related complications (e.g., pneumonia, COPD/asthma exacerbation, cardiovascular events). We also evaluated (post-hoc) RSV-ARI-related systemic corticosteroid and antibiotics use in participants with COPD or asthma. ResultsThe efficacy analyses comprised 12,468 vaccine and 12,498 placebo recipients. Efficacy against RSV-LRTD over three RSV seasons was similar among participants with COPD (75.1%, 95% CI: 40.2-91.4), asthma (65.8%, 31.0-84.7), diabetes (69.8%, 37.5-87.1), and obesity (74.1%, 56.4-85.5) as in the overall study population (62.9%, 97.5% CI: 46.7-74.8). Efficacy was also observed against RSV-ARI in these subgroups. Efficacy against RSV-ARI-related complications was 74.4% (95% CI: 11.2-95.2) in participants with COPD and 60.8% (-9.9-88.7) in those with asthma. Among participants with COPD, 15.4% (1.9-45.4) of RSV-ARI episodes in vaccine vs 22.4% (12.5-35.3) in placebo recipients were treated with systemic corticosteroids, and 46.2% (19.2-74.9) vs 56.9% (43.2-69.8) with antibiotics. ConclusionsPost-hoc analyses of the AReSVi-006 trial suggest that adjuvanted RSVPreF3 may help prevent RSV-ARI, RSV-LRTD, and RSV-related complications in medically stable older adults with underlying medical conditions like COPD and asthma. Trial registrationClinicalTrials.gov: NCT04886596 SummaryPost-hoc analyses of the AReSVi-006 trial suggest that 1 dose of adjuvanted RSVPreF3 may help prevent RSV-related illness and complications over 3 consecutive RSV seasons in subgroups of [≥]60-year-olds with chronic medical conditions, e.g., COPD and asthma.

Background: Extreme-phenotype comparisons allowed the discovery of novel asthma genetic risk loci. However, this approach remains unexplored in epigenome-wide association studies (EWAS). We aimed to identify bulk and cell-specific methylation markers of asthma with severe exacerbations across diverse ancestry groups. Methods: We conducted a meta-EWAS of 739,543 CpGs in whole blood among 1,192 African American and Latino pediatric populations, comparing non-asthmatics and asthma exacerbators. Genome-wide CpGs were followed up for replication in a meta-analysis across 1,516 ethnically diverse participants and in a cross-tissue evaluation of 393 nasal samples. We conducted differentially methylated region (DMRs), cell-type-deconvoluted, and quantitative trait loci analyses (whole-genome sequencing n=1,668; RNA-seq n=1,209). We examined enrichment in traits, pathways, and druggable genes, and analyzed DNAm predictors of plasma proteins and aging. Results: DNAm at 505 CpGs and 119 DMRs in whole blood were associated with asthma exacerbations (p<9x10-8, {lambda}=1.05). We replicated 25 CpGs in blood cells, cross-validated 7 in nasal samples, and detected 42 cell-specific DNAm markers mainly driven by T cells. DNAm at 134 CpGs was associated with gene expression in whole blood, including 118 associations with T-cell receptor genes, and 446 CpGs were regulated by [&ge;]1 genetic variant. We found enrichment for previous associations with environmental exposures, immune disorders, immune and inflammatory pathways, and druggable genes by developmental drugs. 21 methylation-predicted plasma proteins, involved in host defense, and one lung aging clock were associated with asthma exacerbations. Conclusions: The first meta-EWAS of extreme asthma phenotypes identified hundreds of novel DNAm markers, suggesting novel methylation biomarkers and candidate drugs for asthma and supporting the role of T cells.

Abstract Objective: The objective of this study was to compare hospital length of stay and other clinical outcomes between intact fish skin graft (IFSG; Graftguide, Kerecis, Arlington, VA) and synthetic/biosynthetic dermal substitutes (SSS; Integra Dermal Regeneration Template and NovoSorb Biodegradable Temporizing Matrix) in propensity score matched burn patients using the American Burn Association Burn Care Quality Platform. Methods: This retrospective cohort study identified adult patients treated with a single dermal substitute product during hospitalization for acute burn injury. Patients receiving IFSG (n = 93) were matched 1:4 to patients receiving SSS (n = 372) using nearest neighbor propensity score matching on the logit scale. Matching covariates included total body surface area burned (TBSA), patient age, sex), burn severity classification, inhalation injury, and trauma diagnosis. The primary outcome was hospital length of stay (LOS), analyzed using a gamma generalized linear mixed model (GLMM). Secondary outcomes included the incidences of sepsis, graft loss, venous thromboembolism (VTE), and hospital acquired pressure injury (HAPI). A prespecified sensitivity analysis was performed using a broader mixed product cohort. Results: A total of 93 IFSG treated patients from 17 burn centers admitted between the years 2019 and 2025 were matched 1:4 to 372 SSS treated patients from 44 centers. Unadjusted mean LOS was 24.1 days (median 20, IQR 11 to 32) in the IFSG treated group and 36.7 days (median 31, IQR 17 to 52) in the SSS treated group representing a 12.6 day reduction. GLMM-adjusted estimated marginal mean LOS was 24.2 days (95% CI, 20.0 to 29.4) for IFSG versus 33.5 days (95% CI, 30.0 to 37.6) for SSS (ratio 0.723; p = 0.00245), representing a 9.3 day reduction. Sepsis (1.1% vs 4.6%), graft loss (3.2% vs 8.3%), VTE (2.2% vs 2.7%), and HAPI (2.2% vs 3.8%) were all numerically lower in the IFSG treated arm; although GLMM-adjusted odds ratios were not statistically significant for any individual complication. The mixed cohort sensitivity analysis (n = 229 IFSG vs 458 SSS across 67 centers) confirmed the primary finding with GLMM adjusted LOS ratio 0.716 (p = 0.0001). Conclusions: In this propensity score matched analysis of the ABA registry, IFSG was associated with a statistically significant and clinically meaningful reduction in hospital length of stay compared with synthetic/biosynthetic dermal substitutes, in requiring dermal substitution and autografting, with all complication rates, sepsis, graft loss, VTE, and HAPI, numerically lower in the IFSG-treated arm. The shorter hospitalization was not achieved at the expense of safety. These findings support IFSG as a viable alternative to synthetic dermal substitutes in burns requiring dermal substitution and autografting. Prospective studies are warranted particularly in larger burns requiring staged reconstruction.

BackgroundChronic obstructive pulmonary disease (COPD) is a chronic lung condition characterised by accelerated lung aging. Extracellular vesicles (EVs), which can be categorised into large EVs (LEVs) and small EVs (SEVs), may play a critical role in intercellular communication. They contribute to the pathogenesis of COPD by transporting and transferring microRNAs (miRNAs). This study profiles cells and EV-associated miRNAs from both healthy and COPD small airway (SA)-epithelial cells and SA-fibroblasts and identifies the biological pathways associated with these miRNAs. MethodsEVs were isolated from conditioned media of healthy and COPD SA-epithelial cells and SA-fibroblasts, both at baseline and following H2O2 exposure. MiRNAs were extracted from cells and EVs and analysed by small RNA (smRNA) sequencing. ResultsSmRNA sequencing of COPD SA-epithelial cells and EVs revealed that four miRNAs were upregulated and fourteen were downregulated in the cells compared to healthy controls. COPD LEVs displayed nine upregulated and ten downregulated miRNAs, while SEVs showed ten upregulated and eleven downregulated miRNAs. Only one miRNA consistently upregulated in COPD SA-epithelial cells, LEVs, and SEVs. The various differentially expressed miRNAs were primarily associated with cellular senescence pathways. In SA-fibroblasts 39 miRNAs were upregulated in COPD compared to healthy cells. 14 miRNAs were upregulated in COPD LEVs and 11 downregulated, whereas SEVs exhibited twenty upregulated and eleven downregulated miRNAs. Overlap was limited, with only three miRNAs consistently upregulated in SA-fibroblasts and EVs. These miRNAs were linked to pathways related to fibrosis and cellular senescence. Furthermore, oxidative stress alters the miRNA profiles detected in cells and EVs differently between cells from healthy individuals and COPD patients. ConclusionsCOPD alters miRNA signatures in cells and their EVs, with limited overlap between compartments. These COPD-associated miRNAs are enriched in pathways driving cellular senescence and fibrosis, suggesting a potential role in disease progression.