Bleecker, Eugene R.

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 Chronic obstructive pulmonary disease (COPD) manifests later in life and is a leading cause of death worldwide. While smoking-related lung pathology is a long-recognized COPD etiotype, emerging evidence suggests that early-life growth conditions also play an important role. A recently-developed index of early-life growth conditions – the difference between attained height and genotype-predicted height (height-GaP) – has been validated against prospectevely ascertained adverse early-life growth conditions. This study used height-GaP to evaluate the association of early-life growth conditions with COPD phenotype and prognosis later in life. Methods Among current and former smokers with spirometry-defined COPD in the SubPopulations and Intermediate Outcomes Measures in COPD Study (SPIROMICS), we computed height-GaP as the difference between attained height and genotype-predicted height. Regression models were fit for respiratory mortality (defined by primary diagnostic code), dyspnea prevalence (Medical Research Council dyspnea rating >1), chronic bronchitis prevalence, airflow obstruction severity as quantified by FEV1Q, and functional capacity (six-minute walk distance), adjusting for age, age2, sex, race-ethnicity, genotype-predicted height, cigarette smoking status and pack-years. Sensitivity analyses accounted for competing risks of death (Fine-Gray subdistribution hazard model) and accounted for later-life height loss (restricting sample to participants under 50 years). Results Among 1,258 participants with COPD (mean±SD age: 65.4±8.0 years, 42.4% female, mean±SD pack-years: 53.6±28.2, mean±SD FEV1%: 63.3±23.9%), there were 202 respiratory deaths over a median 7.5 years of follow-up (Figure). Larger height-GaP deficit was associated with higher respiratory mortality (adjusted hazard ratio [aHR]: 1.30 [95%CI: 1.12 to 1.50] per 1-SD increment in height-GaP deficit). This association remained significant after accounting for competing events (p=0.001) and when restricted to participants under 50 years (p=0.032). Larger height-GaP deficit was associated with higher dyspnea prevalence (adjusted prevalence ratio: 1.13 [95%CI: 1.02 to 1.25] per 1-SD increment in height-GaP deficit), lower FEV1Q (adjusted mean difference: -0.37 [95%CI: -0.45 to -0.29] per 1-SD height-GaP deficit), and shorter 6-minute walk (adjusted mean difference: -16.6 m [95%CI: -23.1 m to -10.0 m] per 1-SD increment in height-GaP deficit), but not chronic bronchitis or CAT score ≥10 (p>0.05 for each). Conclusions Among current and former smokers with COPD, a quantitative index of early-life conditions was associated with higher respiratory mortality, in addition to dyspnea, airflow obstruction severity and reduced functional capacity. These results suggest that early-life growth conditions may influence COPD phenotype and prognosis later in life.

Abstract 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.

Abstract RATIONALE: Albuterol-budesonide 180/160 µg is indicated in the US for as-needed treatment or prevention of bronchoconstriction and to reduce risk of exacerbations in patients ≥18 years old with asthma. The objective of the ALbuterol-budesonide Treatment in Acute airway obstruction (ALTA) study (NCT05555290) is to assess comparative efficacy, safety, and mechanisms of action of albuterol-budesonide 180/160 µg versus albuterol 180 µg in treating and preventing bronchoconstriction. This report describes the clinical profiles of patients meeting criteria for randomization into the trial. METHODS: ALTA is a phase 3b, multicenter, randomized, double-blind, 2-period, cross-over study evaluating the effects of repetitive dosing of albuterol-budesonide 180/160 µg versus albuterol 180 µg for treating adults treated as intermittent asthma and experiencing acute airway obstruction induced by repeated mannitol challenges. Inclusion criteria evaluated during screening include asthma diagnosis ≥6 months, prescribed and utilizing albuterol as the only asthma treatment for ≥4 weeks, pre-bronchodilator FEV1 ≥1.50 L and FEV1 ≥60% to <90% predicted, and positive response to a mannitol challenge (decrease in FEV1≥15% at ≤635 mg cumulative mannitol dose). Exclusion criteria include clinically significant lung disease other than asthma; any smoking in the prior 6 months or ≥10 pack-year smoking history; or a clinical encounter for asthma worsening within the past 4 weeks. RESULTS: Thus far, 84 patients have met the criteria for randomization into ALTA. Mean(SD) age=44.9(13.7) years, 56.0% female, 40.5% African American, 9.5% Hispanic/Latino. Clinical characteristics include 10.7% with 1 prior-year severe exacerbation; mean(SD) fractional exhaled nitric oxide=37.0(37.4) ppb; mean(SD) baseline pre-bronchodilator FEV1=2.464(0.538) L; mean(SD) baseline percent predicted FEV1=76.7(7.9)%; mean(SD) % fall in FEV1 with mannitol challenge=22.1(7.3)% at a mean(SD) cumulative mannitol dose of 146.4(176.3) mg. Despite being treated for intermittent asthma, based upon symptoms, lung function, and exacerbation history, no patients met NAEPP 2007 criteria for intermittent disease, and 13.1% fell into the mild, 78.6% moderate, and 8.3% severe persistent asthma categories (Figure). With respect to asthma control, as measured by Asthma Impairment and Risk Questionnaire scores, 60.7% had well-controlled, 20.2% not well-controlled, and 19.1% very poorly controlled disease. CONCLUSION: The baseline characteristics of patients in the ALTA study reveal that patients treated as intermittent asthma exhibit heterogeneity in clinical characteristics, airway hyper-reactivity, T2 inflammation, and disease severity and control. Additional genomic and biomarker data are forthcoming and altogether will provide an opportunity to address the mechanism of albuterol and budesonide interactions in a broad spectrum of asthma phenotypes.

Abstract RATIONALE: Airway remodeling, a key characteristic of severe asthma, leads to progressive loss of lung function and incomplete reversibility of airflow obstruction. We examined the effect of benralizumab on lung function in patients from the pooled SIROCCO (Bleecker ER, et al. Lancet 2016; PMID: 27609408) and CALIMA (FitzGerald JM, et al. Lancet 2016; PMID: 27609406) studies, utilizing a new analysis of spirometry to highlight important changes in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) throughout the studies. METHODS: This retrospective analysis pooled data from the randomized, placebo-controlled, double-blind Phase 3 SIROCCO and CALIMA studies. SIROCCO enrolled patients with severe asthma, while CALIMA enrolled patients with moderate-to-severe asthma, both with a planned 2:1 randomization for baseline blood eosinophils ≥300 cells/μL versus <300 cells/μL. All patients (aged 12-75 years) had ≥2 exacerbations in the previous year, despite use of medium- to high-dose inhaled corticosteroids plus additional controllers. Patients in this analysis received subcutaneous benralizumab 30 mg every 8 weeks (Q8W; first three doses given every 4 weeks) for 48 weeks in SIROCCO and 56 weeks in CALIMA. The changes in FEV1 and FVC following bronchodilator (BD) were measured at baseline and study end. Effects on FEV1 and FVC were further stratified by baseline eosinophil count (≥300 cells/μL or <300 cells/μL). Results are reported as mean (standard deviation). RESULTS: Overall, 839 patients received benralizumab Q8W; 557 had a baseline eosinophil count of ≥300 cells/μL and 282 had <300 cells/μL. At baseline, pre- and post-BD FEV1 were 1722 mL (615; n=837) and 2128 mL (755; n=813). At study end, pre- and post-BD FEV1 were 2029 mL (756; n=735) and 2225 mL (800; n=738). At baseline, pre- and post-BD FVC were 2865 mL (905; n=837) and 3285 mL (971; n=813). At study end, pre- and post-BD FVC were 3214 mL (1010; n=735) and 3379 mL (1021; n=738). Pre-BD FEV1 and FVC improved by 307 mL and 349 mL and post-BD FEV1 and FVC improved by 97 mL and 94 mL between baseline and study end, respectively. Stratified by baseline eosinophil count, findings were similar in both groups (Figure). CONCLUSIONS: Benralizumab treatment resulted in both improved FEV1 and FVC while maintaining BD response in patients with uncontrolled, moderate-to-severe asthma. Improvements were seen in patients with baseline eosinophil counts of both ≥300 cells/μL and <300 cells/μL. These results may reflect reduced hyperinflation, potentially due to improved airway inflammation and mucus plugging.

Abstract Rationale Reliable data about the natural history of lung function decline in alpha-1 antitrypsin (AAT)-deficient Pi*MZ heterozygotes is largely missing. Objectives We hypothesized that, in adults with a tobacco smoking history, lung function deteriorates faster in Pi*MZ compared with the Pi*MM genotype. Methods We identified 1,856 Pi*MM and 79 Pi*MZ participants with ⩾20 pack-years tobacco smoking history from the SPIROMICS (Subpopulations and Intermediate Outcomes Measures in COPD Study) cohort by DNA sequencing and followed them over a median of 4.8 years, comparing radiographic and clinical characteristics between the two groups over time using regression models. Results Adjusted for age, sex, race, smoking pack-year history, and smoking status, Pi*MZ participants had a lower baseline percent predicted forced expiratory volume in 1 second (FEV1) (65.4% vs. 75.1%; difference 95% confidence interval [CI], −15.4% to −3.9%), more radiographic emphysema (<−950 Hounsfield units%, 12.9% vs. 7.8%; difference 95% CI, 2.8% to 7.5%), and nonsignificantly lower lung density. In the longitudinal analysis, the FEV1 annual rate of decline was similar in both groups over the course of the study (−34.5 ml/yr vs. −34.6 ml/yr for Pi*MZ and Pi*MM; difference 95% CI, −16.9 to 17.1 ml/yr). There were no significant differences between Pi*MZ and Pi*MM individuals in the annualized change in lung density, emphysema, patient-reported outcomes, exacerbations, or survival. The proportion with faster FEV1 decline (annual loss ⩾40 ml) was similar in Pi*MZ and Pi*MM groups. In both groups, faster FEV1 decline was associated with more air trapping and small airway disease at baseline. In Pi*MZ only, faster decline was associated with higher blood eosinophil counts (310 vs. 220 cells/μl; difference 95% CI, 30 to 140 cells/μl). In the subgroup analysis limited to a small number of currently smoking participants, no significant differences in longitudinal outcomes were found. Conclusions Despite a lower FEV1 and more emphysema at enrollment, the longitudinal analysis did not demonstrate significantly greater lung function decline or lung density loss in Pi*MZ compared with Pi*MM participants with tobacco smoking history. Limited sample size and duration of longitudinal follow-up constrain generalizability of our findings, thus prohibiting the conclusion that longitudinal trajectories did not differ between these groups. However, our results may suggest that earlier life events could be responsible for more extensive lung disease at enrollment in Pi*MZ compared with Pi*MM tobacco-exposed individuals.

Abstract Rationale Dysanapsis refers to a mismatch between airway tree caliber and lung size arising early in life. Dysanapsis assessed by computed tomography (CT) is evident by early adulthood and associated with chronic obstructive pulmonary disease (COPD) risk later in life. Objectives By examining the genetic factors associated with CT-assessed dysanapsis, we aimed to elucidate its molecular underpinnings and physiological significance across the lifespan. Methods We performed a genome-wide association study of CT-assessed dysanapsis in 11,951 adults, including individuals from two population-based and two COPD-enriched studies. We applied colocalization analysis to integrate genome-wide association study and gene expression data from whole blood and lung. Genetic variants associated with dysanapsis were combined into a genetic risk score that was applied to examine association with lung function in children from a population-based birth cohort (n = 1,278) and adults from the UKBiobank (n = 369,157). Measurements and Main Results CT-assessed dysanapsis was associated with genetic variants from 21 independent signals in 19 gene regions, implicating HHIP (hedgehog interacting protein), DSP, and NPNT as potential molecular targets based on colocalization of their expression. A higher dysanapsis genetic risk score was associated with obstructive spirometry among 5-year-old children and among adults in the fifth, sixth, and seventh decades of life. Conclusions CT-assessed dysanapsis is associated with variation in genes previously implicated in lung development, and dysanapsis genetic risk is associated with obstructive lung function from early life through older adulthood. Dysanapsis may represent an endophenotype link between the genetic variations associated with lung function and COPD.

AbstractIntroductionPrevious bronchoalveolar lavage fluid (BALF) proteomic analysis has evaluated limited numbers of subjects for only a few proteins of interest, which may differ between asthma and normal controls. Our objective was to examine a more comprehensive inflammatory biomarker panel in quantitative proteomic analysis for a large asthma cohort to identify molecular phenotypes distinguishing severe from nonsevere asthma.MethodsBronchoalveolar lavage fluid from 48 severe and 77 nonsevere adult asthma subjects were assessed for 75 inflammatory proteins, normalized to BALF total protein concentration. Validation of BALF differences was sought through equivalent protein analysis of autologous sputum. Subjects' data, stratified by asthma severity, were analysed by standard statistical tests, principal component analysis and 5 machine learning algorithms.ResultsThe severe group had lower lung function and greater health care utilization. Significantly increased BALF proteins for severe asthma compared to nonsevere asthma were fibroblast growth factor 2 (FGF2), TGFα, IL1Ra, IL2, IL4, CCL8, CCL13 and CXCL7 and significantly decreased were platelet‐derived growth factor a‐a dimer (PDGFaa), vascular endothelial growth factor (VEGF), interleukin 5 (IL5), CCL17, CCL22, CXCL9 and CXCL10. Four protein differences were replicated in sputum. FGF2, PDGFaa and CXCL7 were independently identified by 5 machine learning algorithms as the most important variables for discriminating severe and nonsevere asthma. Increased and decreased proteins identified for the severe cluster showed significant protein–protein interactions for chemokine and cytokine signalling, growth factor activity, and eosinophil and neutrophil chemotaxis differing between subjects with severe and nonsevere asthma.ConclusionThese inflammatory protein results confirm altered airway remodelling and cytokine/chemokine activity recruiting leukocytes into the airways of severe compared to nonsevere asthma as important processes even in stable status.