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Interleukin 33 (IL-33) is a cytokine of the IL-1 family that acts as an alarmin in both innate and adaptive immunity. IL-33 is constitutively nuclear in epithelial and endothelial cells, where its activity is limited by nuclear retention. Release of IL-33 in response to cellular stress or injury can mediate type 2 immune responses or tissue repair, depending on the local tissue environment. IL-33 activity is regulated at multiple levels, including nuclear retention, oxidation, proteolytic processing, and metabolic regulation. Following its release, oxidation rapidly suppresses IL-33 activity, while mast cell and neutrophil proteases can generate smaller active fragments that target cells expressing the IL-33 ST2 receptor. Simultaneously, tissue metabolic status influences cellular responsiveness through the mTORC1 and AMPK pathways, which link metabolic capacity to effector function. These conditions may explain why IL-33 can mediate an inflammatory response, but in other circumstances, it contributes to tissue repair. Such pleiotropic properties may also underline the variability in clinical responses to IL-33/ST2-targeted therapies across various diseases. The appreciation of IL-33 as a cytokine whose activity is conditioned by its structural, redox, and metabolic environment is critical to optimizing its therapeutic potential as a target.

Objective To evaluate the effects of mepolizumab therapy on the blood transcriptome in patients with severe eosinophilic asthma (SEA) and to determine whether changes in gene expression predict responsiveness to mepolizumab treatment. Methods Fourteen consecutive patients diagnosed with SEA were prospectively enrolled. Each patient had sequential blood samples obtained pre-initiation and at 4, 8, and 12 weeks post-initiation of mepolizumab. Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples for bulk RNA sequencing. Paired differential expression (DE) gene analysis was performed comparing baseline gene expression versus all timepoints. Changes in gene expression were also compared between responders versus nonresponders to mepolizumab treatment. Finally, gene set enrichment analysis was evaluated across timepoints and its interaction with the response to mepolizumab treatment. Results Principal component analysis of all genes demonstrated a homogeneous distribution, which did not separate into distinct groups based on either timepoint or therapeutic response. At week 12, 149 genes had significant DE (FDR < 0.05) compared to baseline. When performing all-way timepoint comparisons, 74 genes (63 protein-coding) were found to be downregulated at weeks 4, 8 and 12 compared to baseline, but no differences were observed between post baseline timepoints. Twenty-eight genes (16 protein-coding) did change with progression of time and were associated with response to therapy, and 56 protein-coding genes distinguished responders and nonresponders. At week 12, nonresponders had a high enrichment of genes involved with signaling pathways, including cytokines, growth factors, cell differentiation markers, and protein kinases. Conclusion In this exploratory study, mepolizumab use was associated with limited global transcriptomic separation with some preliminary differential-expression and enrichment findings. No definitive mechanistic or predictive response signatures were identified due to the study limitations. Future studies, including larger cohorts followed for longer durations with interrogation of specific immune subsets, may offer additional insight into the pathophysiology of severe eosinophilic asthma and into predicting response to mepolizumab treatment.

Abstract Rationale Asthma and obesity are common comorbidities, both driven by inflammation and oxidative stress. Oxylipins are derivatives of polyunsaturated fatty acids that regulate the onset and resolution of inflammation. Oxylipin profiles are altered in obesity and have been shown to differentiate asthma from non-asthma; however, the association between oxylipins and asthma outcomes and the impact of obesity is not known. This study aims to identify differences in serum oxylipins associated with asthma morbidity and evaluate the effect modification by BMI. Methods We analyzed 150 participants in the Best African American Response to Asthma Drugs (BARD) clinical trial. Ninety oxylipins were quantified using liquid chromatography tandem mass spectroscopy from serum obtained at the time of randomization. Oxylipins found to be above the limit of detection in > 80% of samples were log-transformed and included in the analysis. Asthma severity measures included past 12-month systemic corticosteroid use for asthma exacerbation, spirometry, asthma control and asthma quality of life questionnaires (AQLQ). The associations between oxylipins and asthma outcomes were tested using multivariable regression models adjusted for sex, age, BMI, absolute eosinophil count, percent African ancestry, and child vs adult/adolescent cohort. A false discovery rate (FDR) of < 0.1 is used to determine statistical significance. Results Of the 90 oxylipins measured, 42 (46.7%) were detected in > 80% of all samples and included in the analysis. In multivariable models, the pro-inflammatory arachidonic acid (AA) derivative 5,6-DiHETrE was associated with decreased odds of past 12-month systemic corticosteroid use (FDR-adjusted p-value 0.0628). AA derivatives TXB2, PGF2a, and 6-α-prostaglandin were associated with increased FEV1/FVC (FDR-adjusted p-values=0.0925). Thirteen oxylipins were associated with decreased asthma-related quality of life in multivariable models, including AA metabolites 5S-HETE, 5-KETE, 14,15-EET, LTB4, and Lipoxin A4; dihomo-gamma-linoleic acid metabolites 5-HETrE and 15-HETrE; linoleic acid metabolites 3-OxoODE and 9-OxoODE; and eicosapentaenoic acid metabolites 15-HEPE and 17,18-EpETE, all with FDR-adjusted p-values<0.05. Oxylipin-BMI interaction was significant only in the AQLQ models. In all but LTE4, increased concentrations of oxylipins were associated with a decreased quality of life in individuals with higher BMI (Figure). Six of these oxylipins are products of lipoxygenase activity. Conclusions In this study, we find decreased quality of life with increasing concentrations of pro-inflammatory and resolving oxylipins among those with obesity. These oxylipins are primarily produced via lipoxygenases and may represent an important inflammatory pathway in obesity-associated asthma. Quantification of sputum oxylipins and correlation with serum levels will be important in understanding potential mechanisms and is forthcoming. This abstract is funded by: K12TR004412, R01HL123385, U10HL098075, Parker B. Francis Fellowship, 2L30HL159725

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

Background Respiratory allergic diseases are experiencing changes influenced by genetic factors, environmental shifts, and social and demographic elements. These evolving patterns, together with rapid advances in diagnosis and treatment, require a thorough review of emerging trends. Objective To examine future directions in managing respiratory allergic diseases, focusing on changing disease patterns, environmental factors, diagnostic innovations, and therapeutic advances toward precision medicine. A literature search was conducted in PubMed and Scopus databases covering 2015–2025. Studies addressing human populations with allergic rhinitis or asthma were included, emphasizing emerging patterns, environmental factors, diagnostic technologies, and therapeutic innovations, while reviews, conference proceedings, case reports, and studies without clinical relevance were excluded. Initial screening identified 52 studies, and 21 additional studies were identified through complementary searches, resulting in 73 studies in the final analysis. Summary of findings Climate change is a key factor affecting disease patterns, with pollen seasons starting 10–40 days earlier and yearly emissions increasing by up to 200%. Regarding pathogenesis, early-life rhinovirus C infections with IgE sensitization significantly increase asthma risk (HR = 4.06), while severe asthma shows 40–84% eosinophilic patterns, depending on the assessment approach. On the diagnostic front, advances include multiplex platforms, proteomic biomarkers, and microRNAs. Therapeutically, innovations encompass biologics combined with allergen immunotherapy, nanobody-based therapeutics, and microbiota interventions. Conclusions These developments point toward personalized management of respiratory allergic diseases. However, challenges remain in research with underrepresented populations and accessibility. Moving forward, the key priority is integrating this diverse knowledge into practical strategies that advance precision medicine in respiratory allergic diseases.

Asthma is a heterogeneous chronic respiratory disease driven by diverse inflammatory pathways that vary across patients. The recognition of distinct molecular endotypes has led to the development of targeted biologic therapies that have transformed the management of moderate-to-severe asthma. However, selecting the most appropriate biologic therapy for each patient remains challenging. Health providers often rely on trial-and-error approaches that may delay disease control, increase costs, and expose patients to unnecessary side effects. Biomarkers are key to precision asthma care, as they provide objective measures of underlying disease mechanisms. Established biomarkers such as blood eosinophil count, fractional exhaled nitric oxide, and serum total immunoglobulin E are important for identifying type 2-high asthma. Sputum biomarkers offer direct insight into airway inflammation, but their use is limited by technical complexity and availability across centers. Emerging biomarkers, including proteomic, transcriptomic, metabolomic, and genomic biomarkers, show promise in further refining biologic therapy selection. In addition, digital biomarkers derived from electronic health records, wearable devices, and artificial intelligence-based algorithms offer new opportunities to capture real-world changes in disease and treatment response. Non-medical drivers of health, particularly socioeconomic factors, are increasingly recognized as modifiers of biologic effectiveness and may also be helpful in selecting biologic therapies. This review summarizes the existing evidence on established and emerging biomarkers used to guide biologic therapy selection in asthma. Integrating multiple biomarkers will be essential to improve biological selection, monitor response, and ultimately achieve the goal of remission in asthma.

This JAMA Insights explores the management of severe refractory asthma, including medications, access to specialists, and managing environmental triggers.

Abstract RATIONALE: 4G4G/4G5G SERPINE1 genotypes produce high concentrations of plasminogen activator inhibitor-1 and are associated with worse asthma outcomes. A secondary analysis of the American Lung Association (ALA) SOYA trial showed that soy isoflavones significantly reduced asthma exacerbations versus placebo among patients with 4G4G/4G5G SERPINE1 genotypes. We hypothesized that baseline characteristics predict optimal responders to soy isoflavones among this subgroup. METHODS: ALA-SOYA was a randomized controlled trial that tested the efficacy of soy isoflavones vs. placebo for reducing asthma exacerbations among adolescents and adults with symptomatic asthma. In this responder analysis among participants with 4G4G/4G5G SERPINE1 genotypes, baseline demographic and clinical characteristics were tested for effect modification of the treatment assignment (soy/placebo) on the primary outcome of annualized number of asthma exacerbations using interaction terms in negative binomial regression models, with a significance threshold of p-interaction=0.15. RESULTS: Data were available for n=168 participants. Soy reduced the annualized number of asthma exacerbations relative to placebo among patients with 4G4G/4G5G SERPINE1 genotypes (incident rate ratio (IRR)=0.37, 95% confidence interval (CI): 0.15-0.90, p=0.028). Self-reported adherence to baseline controller therapy was the only significant effect modifier of this association (interaction p=0.115), with those using inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA) controller therapy at least twice weekly experiencing reductions in asthma exacerbations with soy versus placebo (IRR = 0.25, 95% CI: 0.09-0.69; p= 0.007) but not among those using ICS/LABA controller therapy less frequently (IRR = 1.33, 95% CI: 0.22-8.02; p= 0.757). CONCLUSION: Soy isoflavones reduce asthma exacerbations among patients with the 4G4G/4G5G SERPINE1 genotypes and are most effective in those with greater adherence to asthma controller therapy regimens.