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.
Albuterol-Budesonide Treatment in Acute Airway Obstruction: Patient Selection for the ALTA Study
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.