Meyers, Deborah A.

Abstract Introduction Inhaled corticosteroid/fast-acting beta2-agonist combinations are recommended over albuterol-alone as rescue in asthma due to superior exacerbation reduction. In adults with asthma, BATURA and MANDALA demonstrated as-needed albuterol-budesonide 180/160 μg reduced the risk of severe exacerbation by 46% in mild and 28% in moderate-to-severe asthma for patients aged ≥18 years versus albuterol 180 μg. However, albuterol is the long-held rescue therapy standard for treatment of bronchoconstriction. In the ALbuterol-budesonide Treatment in Acute Airway Obstruction (ALTA) (NCT05555290) study, repetitive albuterol-budesonide 180/160 ug versus albuterol 180 ug treatment resulted in equally rapid improvement in lung function over 60 minutes and provided enhanced bronchodilation at 480 minutes post-mannitol challenge: least squares mean/LSM(standard error/SE) [95%CI] difference in ΔFEV1=91.2 (27.4) [36.7-145.7] mL. This post-hoc analysis of ALTA evaluated whether baseline lung function affects treatment response. Methods ALTA was a Phase 3b, multicenter, randomized, double-blind, 2-period, crossover study evaluating efficacy of repetitive albuterol-budesonide 180/160 μg vs albuterol 180 μg in adults with mild asthma experiencing ≥15% fall in FEV1 with cumulative mannitol exposure ≤635 mg. Inclusion criteria included use of short-acting beta2-agonist as the only pre-enrollment therapy for ≥4 weeks and pre-challenge FEV1 ≥1.500 L and 60%-<90% of predicted. Participants received albuterol-budesonide or albuterol at end-mannitol challenge (time 0) and 20, 40, and 60 minutes thereafter. FEV1 was assessed starting pre-mannitol challenge (-30 minutes) and over 480 minutes post-challenge. For participants with baseline FEV1 60%-<80% and 80%-<90% predicted, LSM(SE) [95%CI] difference between treatment arms in ΔFEV1 from time 0 min at 480 minutes was analyzed using a linear mixed effects model. Results 88 randomized participants receiving ≥1 dose of study drug were included: mean(SD) age=44.5(13.7) years; 56.8% female; mean(SD) FEV1=2.462(0.540) L (76.7[7.7]% predicted). 56 participants had baseline FEV1 ≥60%-<80% predicted; 32 had baseline FEV1 80%-<90% predicted. Percent fall in FEV1 post-challenge was similar between lung function subgroups. Improvement in FEV1 post-mannitol (time 0 min) at 480 min was greater with albuterol-budesonide vs albuterol treatment for both FEV1 subgroups: LSM(SE) [95%CI] difference 71.0(29.8) [11.0-131.0] mL, p = 0.021 in the lower and 114.0(55.1) [1.0-227.0] mL, p = 0.048 in the higher baseline FEV1 participants (Figure). There was no significant difference in the treatment by subgroup interaction, suggesting consistent treatment efficacy between subgroups. Conclusions Albuterol-budesonide relieves acute obstruction better than albuterol over time in mild asthma whether or not baseline lung function falls within a normal range. This abstract is funded by: AstraZeneca

Abstract Rationale Asthma contributes substantially to healthcare burden and morbidity through frequent exacerbations. Emerging evidence suggests that genetic factors play a crucial role in modulating susceptibility to asthma exacerbations. To better understand the genetic architecture of exacerbations, we conducted a genome-wide association study (GWAS) in the Tapestry cohort. Methods The Tapestry Study, a large-scale, decentralized and clinical grade genomic sequencing study, conducted Exome+® sequencing at Helix, Inc. on 98,075 Mayo Clinic participants. After excluding patients with ≥10 pack-years of smoking and/or emphysema, we performed a GWAS of asthma exacerbations in 3,960 adults with asthma based on ICD codes. Cases (n = 1,059) were defined as individuals who experienced at least two exacerbations between 2020 and 2025; the remaining 2,901 individuals served as controls. Asthma exacerbations were defined by oral or systemic corticosteroid prescriptions with durations ranging from 3 days up to 28 days. Logistic regression models adjusted for age, sex, BMI, and the first six principal components of ancestry. Replication was performed in 1,273 asthma patients (439 African Americans and 834 non-Hispanic Whites) from the NHLBI-sponsored Severe Asthma Research Program (SARP 1-3), with adjustments for age, sex, BMI, and the first 10 principal components of ancestry. Results Based on a minor allele frequency (MAF) threshold of > 0.05, we analyzed 5,256,135 genome-wide variants. Genome-wide significant associations for asthma exacerbations (p < 5.0 × 10⁻8) included loci at a pseudogene in SMPD4P1 (rs680548, MAF = 0.39, OR = 1.37, p = 9.10 × 10⁻9). Additional variants showing suggestive associations included loci within ENDOD1 (rs638776, OR = 0.69, p = 1.20 × 10⁻6), PCSK2 (rs2206454, OR = 1.32, p = 3.53 × 10⁻6), RBFOX1 (rs17667084, OR = 0.60, p = 5.11 × 10⁻6), and CDC42EP3 (rs721660, OR = 1.29, p = 5.68 × 10⁻6). Subthreshold associations in Tapestry including loci at CDC42EP3 (rs4670213, OR = 1.27, p = 1.41x10-5, MAF = 0.36), and SDR39U1 (rs12587663,OR = 0.83, p = 5.86x10-4, MAF = 0.46) were replicated in the SARP longitudinal visit 5 with p-values of 8.523x10-3 (rs4670213, OR = 1.78), and 2.88x10-4 (rs12587663,OR=0.43), respectively. Conclusion Our GWAS for asthma exacerbations in the Tapestry cohort identified variant loci relevant to mitophagy mechanisms (CDC42EP3, PMID: 40783597), immune signaling and RNA splicing regulation (RBFOX1, PMID: 31301374), and neuromodulatory pathways (PCSK2, PMID: 32794589), all previously implicated in asthma pathophysiology. Collectively, these findings highlight potential novel genetic contributors to asthma exacerbations and provide a foundation for improving risk stratification and therapeutic targeting in asthma management. This abstract is funded by: This abstract is funded by: Mayo Clinic Funding: X01 from the NHLBI for TOPMed whole-genome sequencing and NIH grants R01 HL142992, HL69116, HL69167, HL69170, HL69174, U10 HL109164, U10 HL109257, U10 HL109146, U10 HL109172, U10 HL109250, U10 HL109250, U10 HL109250, U10 HL109168, U10 HL109152, U10 HL109086, U10 HL109046.

Abstract Rationale Higher African genetic ancestry has been associated with lower lung function, among individuals from specific racial-ethnic groups. The influence and interactions of genetic variation and ancestry in lung function is poorly understood. This study investigates ancestry-associated loci influencing lung function via admixture mapping and fine-scale allelic association. Methods 512 African American patients with asthma (≥12 years) from the Severe Asthma Research Program and Collaborative Study on the Genetics of Asthma (SARP/CSGA) cohorts were genotyped on the OmniExpress and HumanHap1M arrays or had whole-genome sequencing (WGS). For admixture mapping, global ancestry was inferred using ADMIXTURE and local ancestry estimated using RFMix v1.5.4 with CEU (N = 99) and YRI (N = 108) references across 15,095 local ancestry segments. Peak regions and contiguous segments (p < 10-3) were fine mapped in SARP using local ancestry estimated from WGS with MAF ≥0.03. The Local Ancestry Adjusted Allelic Association (LAAA) model was used to fine map local genetic effect, local ancestry effect, and the interaction between the two, adjusted for age, sex, height, BMI, cohort, and percentage global African ancestry. SNPs with local genetic or interaction p < 10⁻³ were tested for replication in 282 adolescent/adult participants from the Best African Response to Asthma Drugs (BARD) cohort genotyped with the MEGA array imputed to TOPMed (MAF ≥0.03). Results Mean African genetic ancestry was 81.3% in SARP and 80.1% in BARD. In SARP, African genetic ancestry was inversely associated with lung function (FEV₁:β = −7.9, p = 0.005; FVC:β = −9.0, p = 0.004), with stronger effects in females (FEV₁: β = −9.3, p = 0.003; FVC: β = −11.4, p = 0.001) than males (FEV₁:β = −6.4, p = 0.237; FVC:β = −5.7, p = 0.340). Similar total and sex-specific associations were identified in BARD. Admixture mapping in SARP/CSGA identified significant peaks for maximum FVC (p < 1.87 × 10⁻4) on chromosomes 8 and 17 near RP1 and RBFOX3, and near-significant peaks on chromosome 5 near IQGAP2, SNRPCP2, SV2C and for the maximum FEV₁/FVC ratio on chromosome 10 near PCDH15. Fine mapping identified the top SNP on chromosome 8 (rs73587686; p-allele-dose=9.0x10-5; RGS20; q11.23), with 62 additional SNPs overlapping RGS20. SNP rs7825816 was also identified in SARP (β = 2.35, p-allele-dose =1.03 × 10⁻4) and replicated in BARD (β = 1.15, p-allele-dose =0.03). In BARD, LAAA also identified eight additional SNPs (p ≤ 0.05) in the same LD block (chr8:53914976-53918297) overlapping with RGS20, ATP6V1H, and TCEA1. Conclusions We identified multiple chromosomal regions associated with lung function in asthma patients of predominantly African genetic ancestry. Lung function associations were strongest at genetic variation near a key that was replicated in an independent asthma cohort. This abstract is funded by: R01 K08 HL118128, R01 HL142992, R01 NR013700, R01 HL69167, R01 HL161674, HL69116, HL69167, HL69170, HL69174, U10 HL109164, U10 HL109257, U10 HL109146, U10 HL109172, U10 HL109250, U10 HL109250, U10 HL109250, U10 HL109168, U10 HL109152, U10 HL109086-04, U10 HL098115, HL098102, HL098096, HL098075, HL098090, HL098177, HL098098, HL098107, HL098112, HL098103, and K12 HL89992

ABSTRACT Background Chronic obstructive pulmonary disease (COPD) is associated with musculoskeletal comorbidities, including cachexia. Weight loss (WL) is the major criterion for cachexia and increases risk for mortality in COPD. Risk factors for WL in COPD are incompletely understood. We performed this whole genome sequencing (WGS) analysis to identify genetic risk variants for WL in COPD. Methods We studied 16 972 participants from the Trans‐Omics for Precision Medicine (TOPMed) Initiative and All of Us Research Program. COPD was diagnosed using spirometry in TOPMed, while diagnosis codes were used in All of Us. WL was defined as WL ≥ 5% or a final body mass index (BMI) < 20 kg/m 2 . WGS data came from white blood cells in all cohorts. Single‐variant testing was conducted on both race‐ and study‐stratified cohorts and in a cosmopolitan, ancestry‐independent manner using GENESIS in TOPMed and SAIGE in All of Us. SAIGE‐GENE+ gene‐based analyses were performed on race‐stratified and cosmopolitan cohorts. Single variant meta‐analyses were conducted using METAL within (B/AA and NHW analyses of Black/African–American and non‐Hispanic white participants, respectively) and across racial groups (COSMO). Rare variant gene‐based results were combined using Fisher's method. Transcriptomic effects were predicted using MetaXcan. We used the GWAS Catalogue to analyse for colocalization with other related traits. Results Two single variants were associated with WL in COPD among All of Us participants: one intronic variant in HCN1 in Black/African–American participants (chr5:45271359:TACACAC:T, odds ratio with 95% confidence interval (OR (CI 95 )) = 2.43(1.78–3.31), p = 1.95 × 10 −8 ) and one intergenic variant between PPP4R2 and PDZRN3 in the cosmopolitan and NHW cohorts (chr3:73345901:A:G, OR (CI 95 ) = 0.21(0.12–0.35), p = 8.84 × 10 −9 in cosmopolitan and OR (CI 95 ) = 0.18(0.10–0.33), p = 9.44 × 10 −9 in NHW). Single‐variant meta‐analysis identified two loci associated with WL in COPD: five variants within DRAIC in the B/AA meta‐analysis (lead variant chr15:69571341:A:G, OR (CI 95 ) = 1.37(1.23–1.51), p = 1.29 × 10 −9 ) and two intronic variants within RFX3 in the cosmopolitan meta‐analysis (lead variant chr9:3390983:T:C, OR (CI 95 ) = 1.50(1.31–1.73), p = 1.06 × 10 −8 ). Rare variants within RNU6‐565P (NHW analysis in All of Us; p = 2.83 × 10 −7 ) and LOC339298 (B/AA analysis in All of Us, p = 1.85 × 10 −6 ) were associated with WL in COPD. The RNU‐565P signal remained significant after combination with TOPMed results (p combined = 1.23 × 10 −6 ). MetaXcan predicted differential expression of LNC00959 in visceral adipose tissue ( p = 1.16 × 10 −6 in COSMO analysis). Colocalization analyses identified genomic associations between BMI and variants in or near DRAIC , RFX3 , PDZRN3 , and LINC00959 . Conclusions In the first WGS analysis of WL in COPD, we have identified seven novel loci. Further characterization of these loci will validate our findings and improve our understanding of the molecular pathophysiology of this condition.

Introduction Despite the identification of multiple susceptibility loci by genome-wide association studies (GWAS), considerable chronic obstructive pulmonary disease (COPD) heritability remains unexplained. Aim To identify interaction networks of airway epithelial cell DNA methylation in COPD and further explore potential correlations with airway bacterial composition, as potentially collective regulators of biological pathways influencing COPD severity. Methods Using DNA isolated from bronchial airway brushings of 67 ever-smokers (>20 pack-years) from the SubPopulations and InteRmediate Outcomes Measures in COPD Study (SPIROMICS), we assessed proportion of DNA methylation (β) by epigenome-wide association study (EWAS) and examined associations of differentially methylated CpG probes (DMPs) with risk for moderate-to-severe COPD (N=34) versus absent or mild COPD (N=33). We tested co-methylation modules generated by Weighted Correlation Network Analyses (WGCNA) for associations with moderate-to-severe COPD and with bacterial genus-level relative abundances (16S rRNA sequencing). Results EWAS-identified nominally significant DMPs enriched for lung function GWAS loci. Eigengenes in six WGCNA modules were associated with moderate-to-severe COPD (false discovery rate <0.05). Four of those modules were enriched for forced expiratory volume in 1 s/forced vital capacity GWAS loci, and five overlapped with DMPs from EWAS. Overlapping CpG loci in three COPD-associated modules were adjacent to mucin genes; one had 10 genes highly ranked by connectivity with MUC5B, including important pathway genes: B3GNT6 , DGKI and ITGA8 . CpGs in an independent COPD-associated module showed the most correlations with Rothia , with directionality suggestive of negative associations with moderate-severe COPD. Conclusions Bronchial epithelial DNA methylation modules enriched for lung function GWAS loci associate with COPD severity in SPIROMICS. Potential module relationships to bronchial bacterial composition require further validation.

Rationale Immunoglobulin A (IgA) deficiency, a rare, highly heritable trait, is associated with frequent pulmonary infections, emphysema, airway changes and low lung function; however, it is unclear if reduced IgA levels may affect lung structure and function. Methods Serum IgA, IgA1 and galactose-deficient IgA1 (Gd-IgA1) levels were measured in the population-based Multi-Ethnic Study on Atherosclerosis (MESA). The MESA Lung Study measured percent emphysema on cardiac CT and airway dimensions on chest CT, and performed spirometry. Regression models were evaluated after adjustment for demographic and CT factors. Mendelian randomisation (MR) analyses were conducted using genetic variants from the Trans-Omics for Precision Medicine (TOPMed) programme. A replication analysis was performed in the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS). Measurements and main results Among 5497 participants, lower log-normalised serum IgA levels were associated with greater percent emphysema (β=−0.084; 95% CI −0.14 to –0.026; p=0.005), which was confirmed on MR (β=−0.79; 95% CI −1.4 to –0.18; p=0.011). Greater log-normalised serum Gd-IgA1 levels were associated with airway wall thickness (β=0.0079; 95% CI 0.0017 to 0.014; p=0.012; n=2580) and decline in the forced expiratory volume in one second (FEV1) (β=−0.012; 95% CI −0.021 to –0.0036; p=0.0055; n=2778) and FEV1/forced vital capacity (FVC) ratio (β=−0.0028; 95% CI −0.0048 to –0.00084; p=0.0054; n=2778). Conclusion Lower serum IgA levels were associated with greater percent emphysema. Additionally, higher Gd-IgA1 levels were associated with airway wall thickness and lung function decline. These findings support a protective role of IgA in emphysema pathogenesis and possible deleterious role of Gd-IgA1 in airway diseases.

Abstract RATIONALE. Significant sex-differences exist in asthma across the lifespan. Asthma prevalence and severity are greater in pre-pubescent boys compared to girls but greater in women after puberty. In women, asthma may improve after menopause when sex hormones wane. To address potential mechanisms underlying these changes, we compared the airway transcriptomics signatures of post-menopausal vs. premenopausal women. METHODS. We used bulk RNA seq data from bronchial epithelial cells from three different cohorts (SARP III, GEO-GSE85567, GEO-GSE201955) to perform a comprehensive analysis of differential gene expression and regulation. Data were combined into a meta-analysis, to compare pre-menopausal (n=114 cases with asthma, 48 controls) to post-menopausal women (n=52 cases with asthma, 13 controls). Differential gene expression between pre- and postmenopausal women was analyzed separately for asthma (Figure 1A) and control groups (not shown). Significant differentially expressed genes (DEGs) were identified by contrasting effect sizes (log fold-changes) between asthma and control groups using a Z-score interaction test. Accordingly, a scatter plot (Figure 1B) was created to represent whether differential gene expression between pre- and post-menopausal conditions is modified by disease status (asthma vs. control). The scatter plot also highlights that these findings are related to asthma per. se. and not to normal aging and menopausal transition. Pathway enrichment analysis was conducted using the differential expression data, followed by differential regulation analysis of the identified pathways. Statistical significance was assessed using a false discovery rate (FDR) threshold of 5%. RESULTS. Out of 15,468 genes that passed quality control, 19 genes were differentially expressed in bronchial epithelial cells from pre- and post-menopausal women with asthma (as compared to controls) (Figure 1A). Of these, 5 genes were down-regulated (ITLN1, POSTN, FCRL3, CCL22, PCSK6), and 14 genes were up-regulated (SPP1, S100A9, A2ML1, TNFRSF10C, CSF3R, OLFM1, C1QL2, NLRP3, HAL, PI3, RNASE1, TMEM178B, TNNI3, RNF175) when comparing pre- and post-menopausal women with asthma (Figure 1A). Of these 19 DEGs, 14 were differentially expressed in pre- as compared to post-menopausal women with asthma, but not in controls (Figure 1B). Comparing pre- to post-menopausal women with asthma, biologic pathways related to the innate and adaptive immune system activation and mitochondrial function (Electron transport Chain oxidative phosphorylation and ATP production) were both differentially regulated and expressed. CONCLUSIONS. This analysis highlights several DEGs and pathways that characterize asthma pathogenesis when comparing pre- and post-menopausal women, and emphasize the role of female sex hormones on the immune system response and mitochondrial function in asthma pathogenesis.

Abstract Rationale: MUC5B and MUC5AC are neighboring genes on chromosome 11p15 that encode the two predominant mucins secreted in the respiratory airways. Increased airway mucin concentrations and an imbalance between these two mucins drive COPD symptoms and the development of airflow obstruction or COPD, but the epigenomic regulation of this loci has not been characterized in the airways. Methods: We isolated DNA from bronchial airway brushings of 72 participants with &gt;20 pack-years smoking history from the Subpopulations and Intermediate Outcomes Measures in COPD Study (SPIROMICS). 36 participants had GOLD-based moderate-to-severe COPD (FEV1/FVC&lt;0.70, FEV1&lt;80%) and 36 were without or with mild COPD. We used the Illumina Infinium Methylation EPIC BeadChip Array to assess proportion of DNA methylation (β) spanning 689,937 CpG sites. We evaluated proportional DNA methylation (β) at 96 CpG loci within a 103kB region using matrixQTL for cis-expression quantitative trait methylation (eQTM: 10kB flanks relative to MUC5AC/MUC5B) integrating bulk RNA-seq data and mQTL models integrating gene sequencing data to identify DNA variation associated with proportion eQTM methylation. Models included age, sex, BMI, clinical site, current smoking vs past smoking, total pack-years, three ancestral components of ancestry, chipset, and position. Results: We identified a top eQTM, cg00524486, marginally associated with MUC5B expression (coefficient estimate=8.75, punadjusted=0.0014, pFDR=0.065, Figure 1B). This eQTM was associated with CT scan parametric response mapping-based functional small airways disease (PRM-fSAD, beta coefficient[β]=3.64, p=0.011). We tested for DNA variation associated with methylation of this top eQTM which identified two methylation quantitative trait loci (mQTL: rs885454 [β=0.044, minor allele frequency[MAF]=0.09, pFDR=0.01], rs868902 [β=0.020, MAF=0.43, pFDR=0.08, Figure 1A) associated with cg00524486 methylation, of which the more frequent mQTL, rs868902, was marginally associated with PRM-fSAD (p=0.07) in the larger SPIROMICS cohort with MUC5B DNA sequencing data. Conclusions: This preliminary multi-omic study of the lower airway epithelium demonstrates that the expression of MUC5B is epigenetically regulated by neighboring CpG probe methylation (eQTM) represented by DNA variation (mQTL). These studies require further confirmation in a larger dataset of airway samples and support a role for epigenetic variation as a biologic contributor and biomarker of early COPD pathogenesis.

Abstract Introduction: The airway inflammation of asthma is characterized by immune phenotypes, often classified as Type 2 inflammation high or low. Social determinants of health (SDoH) can influence asthma risk and severity, but whether or not SDoH influence immune phenotypes is unclear. The social deprivation index (SDI) is a composite measure of seven neighborhood level characteristics: poverty level, less than 12 years of education, single parent household, living in rented housing unit, living in overcrowded housing unit, households without a car, and non-employed adults under 65 years of age. The scale of SDI ranges from 1 to 100, correlating with increasing deprivation. We hypothesized that social deprivation influences immune phenotype of asthma, and that deprivation effects vary by sex and race. Methods: Using the American Community Survey summary file spanning 2015 to 2019, we linked SDI to participant zip codes for 680 Black and White participants in the Severe Asthma Research Program (SARP), a NHLBI-multicenter network phenotyping asthma across the US from 2001-2024 (table 1). We compared SDI among the cohort by sex, race and asthma severity, and correlated SDI to superoxide dismutase (SOD) and T2-high biomarkers, such as eosinophils, IgE and Fraction of Exhaled Nitric Oxide (FENO). Results: SDI is similar across healthy and asthmatic participants (SDI: median [interquartile range]: healthy: 40 [56]; asthmatics: 51 [53], P = 0.53). When evaluated by race, SDI is significantly higher in Black asthmatics, independent of sex (SDI: Black male: 76 [4], White male: 35 [45]; P&lt;0.0001; Black females: 77 [35], White females: 40 [45]; P&lt;0.00010). Within SARP asthmatics, SDI shows a positive association with the T2 inflammatory markers, log IgE (R=0.13 [90%CI: 0.1, 0.2)] and log FENO (R=0.15 [90%CI: 0.1, 0.2]), while it correlates negatively with log of absolute neutrophil count (R= -0.12 [90%CI: -0.19,-0.1]). The antioxidant enzyme SOD increases with SDI (R=0.11, [90% CI: 0.04, 0.17]). Notably, within Black asthmatic males only, SDI is associated with Type 2 biomarkers, showing a positive correlation with log FENO (R=0.24 [90%CI: 0.1,0.4]) and negative correlation with log IgE levels (R= -0.25, [90% CI: -0.4, -0.1]). No association was found between SDI and eosinophils or with SOD in Black males. Conclusions: Neighborhood level social deprivation is associated with a unique asthma phenotype in Black males. Black males living at high social deprivation have a lower IgE and higher FENO, with no change in SOD activity.

Abstract Rationale: Individuals with chronic obstructive pulmonary disease (COPD) have different clinical trajectories, some with minimal symptom burden, others experiencing recurrent exacerbations, the most severe of which require hospitalization. Existing diagnostics, including spirometry and symptom assessments, lack the precision to identify high-risk patients who may benefit from timely preventive therapies. Nuclear cell-free DNA (ncfDNA) is a well-established marker of systemic tissue injury, implicated in amplifying inflammation by triggering type 1 interferon release by activating DNA-sensing pathways. Because COPD is accompanied by inflammation and tissue injury systemically, we hypothesized that ncfDNA is associated with increased risk of severe exacerbations requiring hospitalization. Methods: Design: We utilized baseline plasma samples randomly selected from 672 individuals with COPD from the Subpopulations and Intermediate Outcomes Measures in COPD Study (SPIROMICS) cohort, which prospectively collected exacerbation numbers and type. The primary endpoint was exacerbation requiring hospitalization. Secondary endpoints included total number of exacerbations (defined as use of oral steroids, antibiotics, or healthcare utilization) and severe exacerbations (defined as requiring emergency room care or hospitalization). Measure: We measured plasma ncfDNA using digital droplet PCR. Analysis: We assessed the association of ncfDNA with exacerbation outcomes using negative binomial regression or Cox regression, adjusting for age, percent post-bronchodilator forced expiratory volume in one second (FEV1), supplemental oxygen use, and smoking status. Results: In total, 57% (n=383) of COPD participants experienced exacerbations, 29% (n=197) at least one severe, and 22% (n=145) requiring hospitalization, the latter at a median of 622 days from enrollment (IQR=287-997). Higher ncfDNA levels at enrollment correlated with measures of COPD severity, including baseline FEV1 (beta = -0.12, 95% CI -0.18 to -0.049, p &lt;0.001). Higher ncfDNA associated with increased risk of COPD exacerbation requiring hospitalization (incidence rate ratio (IRR) 1.40, 95% CI 1.12-1.75, p =0.003) and severe exacerbations (IRR 1.36, 95% CI 1.11-1.67, p=0.002) and a trend towards total exacerbations (IRR 1.11, 95% CI 0.98-1.26, p= 0.09). The primary outcome, risk of time-to-first hospitalization, correlated significantly with higher ncfDNA with hazard ratio (HR) 1.23, 95% CI 1.01-1.49, p=0.037. Conclusion: These results suggest that ncfDNA may serve as a predictor for severe and hospitalization-associated COPD exacerbations. To better understand the relationship between ncfDNA and COPD pathophysiology, follow-up studies should explore longitudinal trends and cfDNA tissue sources, and their link to COPD exacerbations.