BACKGROUND:Biologics targeting type 2 cytokines can inhibit airway inflammation and improve lung function in moderate-to-severe asthma; however, their impact on airway mucosal inflammatory cells is unclear. This study assessed the effects of dupilumab on airway mucosal and systemic inflammation, and related gene expression in patients with persistent asthma. METHODS:In the phase 2a EXPEDITION study (NCT02573233), patients aged 18-65 years were randomised to add-on dupilumab 300 mg (n = 20) or placebo (n = 22) every 2 weeks for 12 weeks. Pre- and post-treatment bronchial biopsies, bronchial brushings, bronchoalveolar lavage (BAL) fluid and blood samples were collected. Clinical and patient-reported outcomes, gene expression, type 2 biomarkers and safety outcomes were assessed. RESULTS:Dupilumab versus placebo improved lung function and asthma control. No significant changes in eosinophils, mast cells or type 2 helper cells were observed in bronchial biopsies. Downregulation of M2 macrophage- and eosinophil-associated gene sets was observed in BAL and brushing samples after dupilumab. Dupilumab decreased multiple circulating type 2 biomarkers in peripheral blood (punadj < 0.001, padj < 0.01), goblet cell numbers (punadj = 0.0336; padj = 0.2554) and mucus area (punadj = 0.0426; padj = 0.2554) in bronchial biopsies versus placebo. The safety profile was consistent with the known safety profile of dupilumab. CONCLUSION:Dupilumab improved lung function and asthma control while reducing circulating type 2 biomarkers. No measurable impact was observed on type 2-associated inflammatory cell numbers in airway bronchial biopsies; however, dupilumab modulated the expression of inflammation-associated gene sets. These findings provide cellular and molecular data that may explain dupilumab-driven mechanisms of improved lung function in patients with type 2 asthma.

Severe asthma is a chronic disease of airway inflammation with substantial morbidity. Deficient specialized pro-resolving mediators (SPMs) are associated with persistent airway inflammation and impaired lung function in some patients with severe asthma. Resolvin D1 (RvD1) is an SPM agonist for inflammation resolution. Plasma RvD1 was measured longitudinally over 5 years in 23 severe asthma patients in the Severe Asthma Research Program (SARP) to identify relationships between clinical parameters, type 2 inflammation, and sputum gene expression. The majority of severe asthma patients had persistently low plasma RvD1; a smaller subgroup had higher RvD1 that fluctuated over time. Correlation analysis indicated a relationship between plasma RvD1 and sputum eosinophilia. A subgroup of severe asthma patients had low plasma RvD1 and high sputum eosinophils (RvD1LoSpEosHi); a separate subgroup had high plasma RvD1 and low sputum eosinophils (RvD1HiSpEosLo). The RvD1LoSpEosHi patient cluster had increased T2 inflammation, lower lung function, and more asthma exacerbations. 42 genes were differentially expressed in RvD1LoSpEosHi severe asthma sputum, including hypoxia-inducible factor 1-alpha (HIF1A). RvD1 significantly downregulated eosinophil HIF-1α expression in vitro. These findings identify a subset of severe asthma patients with low RvD1 and increased sputum eosinophilia, and RvD1 regulation of eosinophil activation ex vivo, suggesting a counter-regulatory role for this SPM in modulating eosinophilic T2 inflammation in asthma.

Type 2 (T2) immune cells dominate the airways of patients with mild-moderate asthma (MMA) with a more complex type 1 (T1)-T2 mixed immune response evident in treatment-refractory severe asthma (SA). We hypothesized that comparing the transcriptomes of the airway epithelium of patients with SA and MMA would reveal molecular signatures associated with more severe disease in the context of a complex immune response. Using our interpretable machine learning tool, SLIDE, meaningful latent factors (context-specific gene co-expression networks) were revealed that distinguished SA from MMA. Unexpectedly, an aberrant high expression of normally host-protective, membrane-tethered, and IFN-inducible mucins, MUC1 and MUC4, was identified in SA. Gene networks in the significant latent factors discriminating SA from MMA corresponded to enrichment of a keratinization program in SA airways. Keratinization was marked by increased expression of the stress keratin KRT16, signifying squamous metaplasia suggesting adaptive reprogramming of the airway epithelium in response to chronic stress. These mucins and KRT16 were inversely associated with lung function in 2 separate asthma cohorts. Imaging of endobronchial biopsies revealed significantly higher KRT16 protein expression in SA compared with MMA that strongly correlated with MUC1 protein expression. Our study identifies dysregulated host-protective and maladaptive repair responses in SA distinguishing from MMA.

Abstract Ether (alkyl/alkenyl) phospholipids, particularly phosphatidylethanolamine (PE) and phosphatidylcholine (PC), are broadly represented in membranes, but their physiological functions are poorly characterized. The antioxidant role of plasmalogens realized via oxidation of sn-1 vinyl bond has been associated with anti-ferroptotic regulatory function. Alternatively, peroxidation of polyunsaturated fatty acid (PUFA) in sn-2-position of alkenyl-PEs can be pro-ferroptotic. Since 15-LOXs generate 15-HpETE-PEs as ferroptotic signals, we explored alkyl/alkenyl-ETE-PE as substrates of enzymatic peroxidation. Using redox lipidomics, biochemical, biophysical, genetic approaches, and molecular dynamics simulations, we established that both isoforms of 15-LOX (15-LOX-1 and 15-LOX-2) selectively oxidize alkyl/alkenyl-ETE-PE (but not alkyl/alkenyl-ETE-PC), forming 15-HpETE-PEs, triggering ferroptotic death, independently of the vinyl bond. We showed that LOX-catalyzed peroxidation rate of sn-1 vinyl bond is ~500-fold lower than sn-2-ETE-PE, thus excluding the antioxidant role of plasmalogens in ferroptosis. We showed 15-LOX-driven production of sn-1-alkenyl-sn-2-15-HpETE-PE acts as pathogenic factor in acute/chronic diseases: asthma, cancer, brain trauma, skin UVB-injury. Thus, 15-LOX-catalyzed bias towards oxidation of alkenyl-ETE-PE may represent a new therapeutic target.

OBJECTIVE:To investigate the relationship between depressive symptoms and risk for COVID-19 hospitalization and death in a United States general population-based sample. METHODS:We studied participants enrolled into observational NIH-funded cohorts from 1971-2010 with ongoing follow-up through 2023. Pre-pandemic Centers for Epidemiologic Studies Depression (CES-D) 10-item scale scores ≥10 defined elevated depressive symptoms. Questionnaires, medical records, and death certificates classified incident COVID-19 as severe (hospitalized/fatal) or non-severe from April 2020 through February 2023. RESULTS:Of 33,565 participants, 633 (1.9%) had incident severe COVID-19 over a mean (SD) follow-up of 453 (207) days. Elevated pre-pandemic depressive symptoms were present in 4,922 (16.3%) of participants. Elevated pre-pandemic depressive symptoms increased the hazard of severe COVID-19 in fully-adjusted (aHR=1.27; 95%CI: 1.03-1.57) models. In sex-stratified models (p-interaction=0.03), elevated depressive symptoms increased the hazard in women (aHR=1.49; 95%CI: 1.17-1.90) but not in men (aHR=0.96; 95%CI: 0.67-1.39). CONCLUSIONS:Pre-pandemic depressive symptoms were associated with increased risk of severe COVID-19 among women in a large US general population-based study of adults, and associations in men were neither confirmed nor ruled out. These results support current CDC recommendations that depression be considered an underlying medical condition associated with higher risk for severe COVID-19 and suggest that increased clinical focus on risk mitigation for COVID-19 and other acute respiratory infections among patients with depressive symptoms is warranted.

BACKGROUND:Asthma is a heterogeneous disease influenced by genetic and environmental factors. Fine particulate matter (PM2.5) exacerbates asthma, likely through oxidative stress pathways, but whether genetic variation modifies this effect remains unclear. METHODS:We analysed data on 948 adults with asthma from the Severe Asthma Research Program (SARP), linking ZIP-code-level PM2.5 exposure with whole-genome sequencing data. We tested 4337 single nucleotide polymorphisms (SNPs) in 120 oxidative stress pathway genes for gene-environment (GxE) interactions with PM2.5 on lung function (forced expiratory volume in 1 s [FEV1] % predicted) using weighted linear regression. Gene expression data from bronchial epithelial cells (n = 170) were used to assess cis-expression quantitative trait loci (eQTLs). FINDINGS:Higher PM2.5 exposure was associated with lower FEV1% predicted (β per μg/m3 = -0.7, p = 0.01). We identified 20 SNPs across seven genes (OXSR1, PXDN, TPO, LRRK2, APP, MSRA, MSRB2) with significant GxE interactions after multiple-testing correction. Five SNPs were also eQTLs, linking PM2.5-modified gene expression to lung function. Minor alleles in OXSR1 and PXDN were associated with reduced gene expression and worsened FEV1% under high PM2.5 exposure. Conversely, TPO variants were associated with higher baseline expression and lower lung function, but under increasing PM2.5 exposure, minor allele carriers showed suppressed TPO expression and improved FEV1%. INTERPRETATION:This study identified 20 SNPs in oxidative stress pathway genes that modify the effect of PM2.5 on lung function in asthma. These findings highlight the importance of integrating environmental context in genetic studies and suggest potential therapeutic targets for pollution-sensitive asthma phenotypes. FUNDING:Supported by NIH grants.

RATIONALE:Bronchiolar dysfunction is associated with asthma exacerbations and poor symptom control. However, the molecular pathophysiology of asthmatic bronchiolar disease is poorly defined. OBJECTIVES:Test the hypothesis that asthmatic bronchioles exhibit disturbances in epithelial biology that produce MUC5AC-dominated mucus plugs. METHODS:Peripheral lung tissues from severe asthmatics, fatal asthmatics (FA), and controls were evaluated with histology, RNA in situ hybridization, and immunohistochemistry. Isolated bronchiolar and bronchial basal cell responses to IL13 were compared in culture. Spatial transcriptomics and multiplex immunophenotyping were performed on excised tissue sections. MEASUREMENTS AND MAIN RESULTS:In excised tissues, severe and FA bronchiolar epithelia, depleted of distal airway secretory cells (DASCs) and enriched in MUC5AC goblet cells, circumscribed MUC5AC-dominated mucus plugs. In cultured bronchiolar basal cells, IL13 suppressed FOXA2 and DASC gene signatures and upregulated MUC5AC expression. Additional studies in severe and FA-excised tissues demonstrated that bronchiolar epithelia were populated by MUC5AC-expressing goblet cell niches heterogeneously distributed within single segments and, indeed, individual bronchioles. Spatial transcriptomics and immuno-proteomics of these MUC5AC-expressing bronchiolar niches identified increased goblet, suprabasal (SERPINB3), and basal cells, juxtaposed to a loss of DASC gene signatures. MUC5AC-high niche bronchiolar basal cells expressed reduced FOXA2 and elevated type-2 inflammatory (T2) gene signatures. Immune cell distributions surrounding asthmatic bronchioles differed from controls but did not correlate with MUC5AC-high niches. CONCLUSIONS:Asthmatic bronchioles exhibit a T2-driven proximalization associated with mucus plugging. MUC5AC-high niches were identified heterogeneously in bronchiolar epithelia independent of immune cell localizations, suggesting asthmatic bronchioles contain cellular niches which perpetuate T2-initiated epithelial remodeling.

Dysregulations of epithelial-immune interactions frequently culminate in chronic inflammatory diseases of the skin, lungs, kidneys, and gastrointestinal tract. Yet, the intraepithelial processes that initiate and perpetuate inflammation in these organs are poorly understood. Here, by utilizing redox lipidomics we identified ferroptosis-associated peroxidation of polyunsaturated phosphatidylethanolamines in the epithelia of patients with asthma, cystic fibrosis, psoriasis, and renal failure. Focusing on psoriasis as a disease model, we used high-resolution mass spectrometry imaging and identified keratin 14-expressing (K14-expressing) keratinocytes executing a ferroptotic death program in human psoriatic skin. Psoriatic phenotype with characteristic Th1/Th17 skin and extracutaneous immune responses was initiated and maintained in a murine model designed to actuate ferroptosis in a fraction of K14+ glutathione peroxidase 4-deficient (Gpx4-deficient) epidermal keratinocytes. Importantly, an antiferroptotic agent, liproxstatin-1, was as effective as clinically relevant biological IL-12/IL-23/ TNF-alpha-targeting therapies or the depletion of T cells in completely abrogating molecular, biochemical, and morphological features of psoriasis. As ferroptosis in select epidermal keratinocytes triggers and sustains a pathological psoriatic multiorgan inflammatory circuit, we suggest that strategies targeting ferroptosis or its causes may be effective in preventing or ameliorating a variety of chronic inflammatory diseases.

Rationale: The club cell secretory protein (CC16), encoded by the SCGB1A1 gene, has an anti-inflammatory role in airways diseases, including asthma (Li, AJRCCM 2023; Voraphani, AJRCCM 2023). We hypothesize that additional pathway genes regulated or co-expressed with CC16 have cumulative effects on asthma severity outcomes by modulating airway inflammation and maintaining lung homeostasis. Methods: As published previously, four genes were downregulated in CC16 knockout experiments and correlated with CC16 levels: BPIFA1, SFTPD, LTF, and LYZ (Iannuzo, Front. Immunol 2023). We developed a four-gene biomarker score in 94 patients with asthma from the NHLBI-sponsored Severe Asthma Research Program (SARP3) who underwent research bronchoscopy for lower airway epithelial brushings, RNA isolation, and bulk RNA sequencing. We log-transformed the raw values of each transcript; obtained standardized residuals from regression models that included sex, age, and batch effects; and summed the standardized residuals of all four proteins to estimate a standardized sum score (Zhai, JACI Allergy 2024). Logistic regression models tested the four-gene score, three-gene score without LTF, and individual transcripts for associations with exacerbations during 12-month follow-up and zero-inflated negative binomial regression for number of exacerbations. Results: 30.85% percent of 94 patients experienced at least one exacerbation at the end of follow-up. The CC16-associated four-gene biomarker score showed protective effects on asthma exacerbation risk with a 54% percent reduction in exacerbation risk for every one-fold higher score (OR=0.46, 95% CI: 0.27-0.78, p =0.0040, Figure 1). Transcript expression of BPIFA1 (OR=0.87, 95% CI:0.66-1.16, p=0.337), SFTPD (OR=0.33, 95% CI:0.04-2.52, p=0.283), LYZ (OR=0.62, 95%CI:0.28-1.39, p=0.248), and LTF (OR=0.36, 95% CI:0.18-0.74, p=0.0053) all indicated protective directionality with respect to exacerbation risk. However, only LTF demonstrated a statistically significant association. When we excluded LTF, the remaining three-gene score showed a trend toward association with risk (OR=0.64, 95% CI:0.40-1.03, p=0.068) and was significantly associated with number of exacerbations (RR=0.49, 95% CI:0.26-0.95, p=0.034). Compared to LTF alone (OR=0.48, PPV=0.50, NPV=0.71, Sensitivity=0.14, AUC=0.65), the combined four-gene score (OR=0.46, PPV=0.60, NPV= 0.73, Sensitivity=0.21, AUC=0.68) showed improved predictive performance. Conclusions: We identified a CC16-associated transcriptomic predictive score for asthma exacerbations, with LTF showing the strongest effect. Although the other three genes showed individually weak and non-significant associations with exacerbations, the three gene score was significant for number of exacerbations.We demonstrate the potential of this transcriptomic score as a predictive biomarker for asthma severity-related outcomes. Further research investigating these genes and their interaction with other CC16-associated immune pathways could provide insight into therapeutic targets.

Rationale: We previously derived three asthma phenotypes from clinical data, quantitative computed tomography (qCT), and computational fluid dynamics (CFD)-incorporated cluster analysis: old, obese, and intermediate groups (AJRCCM 2024;209:A2776). The obese asthma cluster demonstrated worse asthma control test (ACT) and asthma quality of life (AQLQ). We hypothesize that obese asthmatics may experience greater aerodynamic force and pressure in airways, which contribute to poorer asthma control in the setting of less mucus plugging. Methods: Inspiratory and expiratory CTs, clinical data, and mucus plug scores were collected from 172 asthma patients in SARP III. For 97 subjects with high-quality image segmentation, we used CFD airflow simulations of breathing (tidal volume: 6 ml/kg) to compute air flowrate and pressure in individual branches throughout the entire conducting airways. Average aerodynamic force applied around segmental branches were analyzed from pressure and cross-sectional area of each branch at airway generation 3-6. To discriminate effects of obesity and aging, 172 patients were classified into four groups based on age (>65 years old) and obesity (BMI>30). Kruskal-Wallis with Dunn's test and Spearman correlation analysis were used, with statistical significance by p<0.05. Results: CFD-derived peak expiratory aerodynamic force and air pressure around segmental airways were greater in the obese cluster (105±40 µN, 22.7±9.2 Pa, p<0.001 for all) than those in the others (old: 43±13 µN, 8.5±2.8 Pa; intermediate: 37±15 µN, 7.3±3.2 Pa), where force was highly associated with BMI (r=0.81, p<0.001). The obese cluster had higher flowrate (0.004±0.001 L/s, p<0.001) than the others (old: 0.003±0.001 L/s; intermediate: 0.002±0.001 L/s) but did not exhibit different airway luminal area. Greater force and pressure were associated with worse ACT (force r=-0.34, p<0.001; pressure r=0.35, p<0.001) and AQLQ scores (force r=-0.32, p=0.001; pressure r=-0.30, p=0.003). Elderly obese asthmatics had less mucus plugging (1.25±2.2, p=0.004), less functional small airway disease percentage (fSAD%, 7.1±9.0%, p=0.002), and higher post-bronchodilator FEV1/FVC (89.5±12.2%, p=0.004) than the elderly non-obese group (mucus score=9.3±7.2, fSAD%=22.1±18.0%, FEV1/FVC=71.5±7.3%), without significant difference from non-elderly obese asthmatics. Conclusion: qCT-CFD analysis showed that obese patients with asthma may experience higher aerodynamic force and pressure during normal breathing than nonobese asthmatics. This may contribute to greater remodeling and healthcare utilization despite preserved lung function and less mucus plugging in elderly obese asthmatics than in elderly nonobese asthmatics.

Background: Asthma pathophysiology is associated with mitochondrial dysfunction. Mitochondrial DNA copy number (mtDNA-CN) has been used as a proxy of mitochondrial function, with lower levels indicating mitochondrial dysfunction in population studies of cardiovascular diseases and cancers. Objectives: We investigated whether lower levels of mtDNA-CN are associated with asthma diagnosis, severity, and exacerbations. Methods: mtDNA-CN is evaluated in blood from 2 cohorts: UK Biobank (UKB) (asthma, n = 39,147; no asthma, n = 302,302) and Severe Asthma Research Program (SARP) (asthma, n = 1283; nonsevere asthma, n = 703). Results: Individuals with asthma have lower mtDNA-CN compared to individuals without asthma in UKB (beta,-0.006 [95% confidence interval,-0.008 to-0.003], P = 6.23 x 10-6). Lower mtDNA-CN is associated with asthma prevalence, but not severity in UKB or SARP. mtDNA-CN declines with age but is lower in individuals with asthma than in individuals without asthma at all ages. In a 1-year longitudinal study in SARP, mtDNA-CN was associated with risk of exacerbation; those with highest mtDNA-CN had the lowest risk of exacerbation (odds ratio 0.333 [95% confidence interval, 0.173 to 0.542], P = .001). Biomarkers of inflammation and oxidative stress are higher in individuals with asthma than without asthma, but the lower mtDNA-CN in asthma is independent of general inflammation or oxidative stress. Mendelian randomization studies suggest a potential causal relationship between asthma-associated genetic variants and mtDNA-CN. Conclusion: mtDNA-CN is lower in asthma than in no asthma and is associated with exacerbations. Low mtDNA-CN in asthma is not mediated through inflammation but is associated with a genetic predisposition to asthma. (J Allergy Clin Immunol 2025;155:1224-35.)

Despite the availability of effective vaccines and a recent decrease in annual deaths, COVID-19 remains a leading cause of death. Serological studies provide insights into host immunobiology of adaptive immune response to infection, which holds promise for identifying high-risk individuals for adverse COVID-19 outcomes. We investigated correlates of anti-nucleocapsid antibody responses following SARS-CoV-2 infection in a US population-based meta-cohort of adults participating in longstanding National Institutes of Health-funded cohort studies. Anti-nucleocapsid antibodies were measured from dried blood spots collected between February 2021 and February 2023. Among 1419 Collaborative Cohort of Cohorts for COVID-19 Research participants with prior SARS-CoV-2 infection, the mean age (standard deviation) was 65.8 (12.1), 61% were women, and 42.8% self-reported membership in a race/ethnicity minority group. The proportion of participants reactive to nucleocapsid peaked at 69% by 4 months after infection and waned to only 44% ≥12 months after infection. Higher anti-nucleocapsid antibody response was associated with older age, Hispanic or American Indian Alaskan Native (vs White) race/ethnicity, lower income, lower education, former smoking, and higher anti-spike antibody levels. Asian race (vs White) and vaccination (even after infection) were associated with lower nucleocapsid reactivity. Neither vaccine manufacturer nor common cardiometabolic comorbidities were not associated with anti-nucleocapsid response. These findings inform the underlying immunobiology of adaptive immune response to infection, as well as the potential utility of anti-nucleocapsid antibody response for clinical practice and COVID-19 serosurveillance.

Rationale: A subset of patients with asthma have airway pathology characterized by a thickened subepithelial basement membrane zone ("BMZ-thick asthma"). Objectives: To characterize the clinical features of BMZ-thick asthma and to determine if BMZ thickness accompanies specific patterns of inflammation in the airway epithelium. Methods: Design-based stereology was used to quantify BMZ thickness in endobronchial biopsy tissue sections from 109 patients with asthma and 41 healthy control subjects from SARP (Severe Asthma Research Program)-3, whose participants had undergone spirometry and gene expression profiling in airway epithelial brushings. Measurements and Main Results: The upper 90th-percentile value for BMZ thickness in the healthy cohort was 2.9 μM, and 35% of the asthma cohort had values above this upper limit. Compared with patients with BMZ-thin asthma, patients with BMZ-thick asthma were younger and had higher blood eosinophil numbers and serum immunoglobulin E concentrations that were specific to animal proteins. Mean prebronchodilator FEV1 was significantly lower in patients with BMZ-thick asthma than in those with BMZ-thin asthma, but postbronchodilator FEV1 was not. Upregulation of genes signifying IL-13 activation and the presence of mast cells were evident in epithelial brushings in patients with BMZ-thick asthma, but gene signatures for activation by IFN-γ or IL-17 were not. Conclusions: A thickened BMZ marks a subset of younger patients with asthma characterized by higher immunoglobulin E concentrations to animal aeroallergens and by increased bronchomotor tone occurring in the context of airway epithelial cells activated by IL-13 and infiltrated by mast cells.

RATIONALE 15-Lipoxygenase 1 (15LO1) driven ferroptosis induces mitochondrial damage in human airway epithelial cells (AECs), potentially though alterations in mitochondrial membrane potential (ΔΨm), which activates mitophagy (Yamada et al, Nat Commun 2024). These ferroptotic pathways drive abnormal development of ciliated airway AECs in vitro and associate with shorter cilia length and airway obstruction in asthma patients. We hypothesized that ferroptotic pathway activation would alter differentiation trajectories of basal cells, potentially through cell specific reduction of ΔΨm. METHODS AECs were obtained bronchoscopically from healthy controls (HC), mild/moderate (MMA) and severe asthma (SA) (ERS-ATS criteria). Fresh AECs or AECs in air-liquid interface culture (14 days) were analyzed. Cells were stimulated (or not) with IL-13 (2.5 or 10 ng/ml x 5 days), detached and suspended for flow cytometry with cell permeant fluorescent dye, tetramethylrhodamine methyl ester (TMRM) and antibodies against nerve growth factor receptor (NGFR; basal cells), tetraspanin-8 (TSPAN8; goblet cells), tubulin (TUBA1A; ciliated cells) and 15LO1. Cell profiles were generated using flow cytometry and data analyzed by FlowJo software. RESULTS AECs were obtained from 6 HC, 4 MMA and 8 SA patients. They did not differ by age, sex or race. Three SA asthma patients were on a biologic and 2 of them were also on oral corticosteroids. As expected FEV1% predicted was lower and blood eosinophils higher in asthmatic patients. However, there were no differences in fraction exhaled NO. Both 2.5 and 10 ng/ml of IL-13 increased NGFR+ basal cell percentages compared to media control (13% vs 28%, n=15, p<0.001), while ciliated cell percentages decreased (3.5% vs 2.1%, n=13, p=0.006). Similarly, fresh SA AECs (n=7) tended to have higher percentages of NGFR+ basal cells than HCs (n=4) (p=0.109), without difference in ciliated cell percentages (p=0.439). In contrast, there was higher co-localization of TUBA1A+ ciliated cells in NGFR+ basal cells in HCs vs SAs (p=0.046), with a trend to higher co-localization of TSPAN8+ goblet cells in NGFR+ basal cells in SAs (p=0.194). IL-13 increased 15LO1 expression in vitro (n=10, p=0.006) with co-localization in NGFR+ basal cells (n=7, p=0.016) and TUBA1A+ ciliated cells (n=6, p=0.063). IL-13 specifically decreased TMRM in TUBA1A+ ciliated cells (n=3, p=0.007). CONCLUSIONS IL-13-enhanced 15LO1 skews basal cell trajectories towards goblet and away from ciliated cells. This associates with lower ciliated cell ΔΨm, suggesting ferroptotically-stressed mitochondria drive differentiation towards goblet cells while reducing ciliated cells. Further studies are needed to confirm the impact of 15LO1 inhibition on these different trajectories.

BACKGROUND:α1-Antitrypsin deficiency is caused by rare pathogenic variants in SERPINA1, the strongest genetic risk factor for chronic obstructive pulmonary disease. Few studies have evaluated the effects of SERPINA1 variation on asthma severity accounting for critical gene-by-environment interactions with smoking. OBJECTIVE:To characterize the influence of SERPINA1 variation on asthma severity. METHODS:DNA samples from 847 non-Hispanic White and 446 African American participants from the Severe Asthma Research Program underwent SERPINA1 resequencing to identify rare variants. An independent population of 1955 individuals with asthma and α1-antitrypsin concentrations from a Cleveland Clinic Health System (CCHS) database were evaluated for severity measures. RESULTS:In White participants, a history of minimum smoking significantly interacted with SERPINA1 low-to-rare frequency variation to determine risk for asthma-related health care utilization. This was attributed to protease inhibitor type Z heterozygotes (MZ, N = 11), who had a higher frequency of emergency department (ED) visits (6 [54.5%] MZ heterozygotes, odds ratio [OR] = 7.60, 95% confidence interval [CI] = 1.71-39.7, P = .010), hospitalization (5 [45.5%], OR = 16.1, 95% CI = 2.64-150.4, P = .0050) in the past year, and lifetime intensive care unit (ICU) admissions (6 [54.5%], OR = 12.5, 95% CI = 2.44-75.6, P = .0032) compared with 146 individuals without SERPINA1 variants (30 [20.5%] reporting ED visits, 17 [11.6%] hospitalization, and 15 [10.3%] ICU admission). SERPINA1 variant-by-ever smoking interactions in African American participants for ED visits (P = .069) were related to 4 of 6 compound heterozygotes reporting an ED visit. In CCHS, α1-antitrypsin concentrations were inversely associated with moderate-to-severe asthma risk (OR = 0.97 per 10 mg/dL increase in α1-antitrypsin, 95% CI = 0.94-0.99, P = .010) and exacerbations (OR = 0.84 per 10 mg/dL, 95% CI = 0.76-0.94, P = .002). CONCLUSIONS:SERPINA1 variation and α1-antitrypsin concentrations impact asthma severity through gene-environment interactions with minimum smoking.

Background: Asthma is a heterogeneous disease with a diverse array of phenotypes that differ in inflammatory characteristics and severity. Identifying and classifying phenotypes in the real world could provide a foundation to improve and personalize asthma management. Leveraging machine learning in analyzing electronic health records (EHRs) provides an opportunity to identify real-world asthma phenotypes. Objective: We utilized machine-learning techniques applied to EHRs to detect and predict real-world severe asthma (SA) phenotypes and improve the precision of asthma severity diagnoses. Methods: Data from 31,795 asthma patients were extracted from a health care system’s EHR, with 1,112 patients meeting inclusion criteria for analysis. Principal component analysis (PCA) and a Gaussian mixture model classified patients into subject clusters (SCs). Asthma severity was assessed using two predictive models, one based on the American Thoracic Society (ATS) definition and the other a supervised model trained on 50 randomly selected patients whose disease severity was predetermined by 2 independent physicians. Results: Three principal components (PCs) emerged, reflecting lung function (PC1), blood inflammatory markers (PC2), and systemic corticosteroid receipt (PC3). PCA identified 5 distinct asthma phenotypes with significant clinical, physiologic, and inflammatory differences. A supervised model, trained on 50 randomly selected patients, predicted SA with 92% precision and 85% accuracy. SC3 was classified as an inflammatory, SA phenotype, making it highly suitable for biologic therapy. Conclusion: Integrating machine learning with EHRs successfully classified and identified real-world asthma phenotypes, demonstrating the potential of this approach to identify SA for appropriate management and/or clinical studies.