Citations

Abstract Rationale Asthma, a chronic inflammatory airway disease, can be influenced by hormonal fluctuations that affect immune function and airway responsiveness. During in-vitro fertilization (IVF), women undergo sequential hormonal treatments—including gonadotropin administration to stimulate follicle development and induce ovulation, and progesterone and estrogen to support implantation and early pregnancy. These precisely timed hormonal changes may affect asthma symptoms and increase the risk of exacerbations. This study evaluates the hypothesis that undergoing IVF increases the risk of asthma exacerbations prior to, but not during or after pregnancy. Methods Data were extracted from the Mayo Clinic electronic health records. Women were included if their pregnancy was recorded in the Mayo Clinic obstetric delivery dataset. Asthma was defined as the presence of an ICD code J45.xx in combination with a prescription for any asthma medication. For women with multiple pregnancies, only the first pregnancy was analyzed. An asthma exacerbation was defined as a course of oral corticosteroids lasting ≤28 days or a corticosteroid injection. Multivariable logistic regression was used to assess exacerbation risk, adjusting for age, body mass index (BMI), and prior history of diabetes mellitus. Results Among 3,623 pregnant women, 112 underwent IVF treatment. Compared with non-IVF patients, women undergoing IVF were older (mean ± SD: 34.16 ± 5.24 vs. 29.11 ± 5.55, p < 0.001), had lower parity (1.44 ± 0.79 vs. 1.83 ± 1.20, p = 0.001), and fewer full-term deliveries (1.31 ± 0.79 vs. 1.68 ± 1.11, p = 0.001) (Table 1). There were no differences in pre-pregnancy BMI, racial distribution, ethnicity, or prior history of diabetes mellitus. Adjusted analysis indicated that IVF was associated with an increased risk of asthma exacerbation in the year before pregnancy (adjusted OR [95% CI]: 1.097 [1.025-1.173]), but not during (adjusted OR [95% CI]: 1.044 [0.973-1.121]) or after pregnancy (adjusted OR [95% CI]: 1.026 [0.963-1.094]). Conclusion These findings suggest that the preconception hormonal changes associated with IVF may temporarily worsen asthma control. Further studies are warranted to replicate these results, clarify the underlying mechanisms, and guide asthma management in women undergoing fertility treatment. This abstract is funded by: NIH

Abstract Rationale Asthma is a chronic inflammatory airway disorder influenced by pulmonary and systemic factors. Epidemiologic and experimental data suggest associations between asthma, anemia, and reduced iron stores. Sex may modify this relationship: females, with lower baseline iron reserves, menstrual blood loss, and hormone-mediated immune effects, may exhibit greater susceptibility, whereas males, with higher iron stores and androgen-related anti-inflammatory influences, appear less affected. This study tested the hypothesis that diminished iron stores, rather than anemia itself, are associated with asthma, and that this relationship differs by sex. Methods Data were analyzed from nine consecutive NHANES 2-year cycles (1999-2018), a nationally representative U.S. dataset. Lifetime asthma was defined as a prior physician diagnosis and active asthma as “Do you still have asthma?”. Anemia was defined by WHO criteria (hemoglobin <12 g/dL in females and <13 g/dL in males), and iron deficiency as ferritin <30 ng/mL. Accordingly, iron status was categorized as normal, iron deficiency anemia (IDA), iron deficiency without anemia (IDWA), and anemia without iron deficiency (AWID). Analyses followed NHANES guidelines and were conducted with the SURVEY package in R. Results Female participants were older and had lower eosinophil counts, ferritin, and hemoglobin levels, with a higher prevalence of anemia, lifetime asthma, and current asthma. Similar trends were observed among participants with available ferritin data (Table 1). In unadjusted analyses, ferritin levels were inversely associated with lifetime (β = -0.19; p <0.001) and active asthma (β = -0.35; p <0.001), but these associations were not significant after adjustment for sex, age, BMI, race, and log10-transformed eosinophil count (lifetime: β = 0.03; p = 0.61; active: β = -0.08; p = 0.40). In contrast, anemia was associated with increased odds of lifetime (adjusted OR [95% CI], 1.52 [1.21-1.92]) and active (1.50 [1.13-1.99]) asthma in males, but not in females (0.98 [0.86-1.12] and 0.98 [0.83-1.15], respectively). Among males, AWID was associated with active asthma (2.07 [1.08-3.96]), whereas IDA and IDWA were not. No associations were observed among females. Conclusion The relationship between anemia and asthma may be primarily driven by inflammation related to asthma rather than true iron deficiency. After adjustment, ferritin was not independently associated with asthma, whereas anemia—particularly AWID—remained associated among males. These findings suggest that asthma-associated systemic inflammation contributes to anemia of chronic disease, underscoring the need to distinguish inflammatory anemia from nutritional iron deficiency in research and clinical management. This abstract is funded by: NIH

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 Lung fibroblasts (FBs) play a pivotal role in airway remodeling in asthma. During profibrotic and inflammatory conditions, FB undergoes myofibroblast differentiation, which contributes to airway wall thickening, stiffness, and airflow obstruction. Myofibroblast differentiation is a process in which fibroblasts transform into highly contractile fibers in response to profibrotic mediators such as transforming growth factor-beta 1 (TGF-β1). This transition is characterized by increased production of alpha-smooth muscle actin (α-SMA), and the formation of actin stress fibers, which are crucial for contractile machinery. Our previous findings identified the important role of Kisspeptin/KISS1R (Kp/KISS1R) in airway smooth muscle remodeling. However, there is no information about the expression and function of Kp/KISS1R in the lung FB. This study investigates the expression of Kp/KISS1R in lung FB and their role in myofibroblast transition. Methods Primary human lung FBs were isolated from surgical lung resections (Mayo IRB-approved) and cultured in DMEM-high glucose medium with 10% fetal bovine serum and 1% antibiotic/antimycotic. Upon reaching ∼90% confluence, cells were serum-deprived and treated with kisspeptin-10 (Kp-10, 1 µM) in the presence or absence of TGF-β1 (10 ng/mL). Expression of Kisspeptin, KISS1R and α-SMA in FB cells were assessed by western blotting and confocal microscopy. FB filamentous (F)-actin formation was analyzed by staining with phalloidin. In addition, collagen gel contraction assays were performed to study fibroblast contractility. Results We found the ubiquitous expression of kisspeptin and KISS1R in human FB. Notably, we observed that KISS1R expression was significantly reduced in asthmatic FB compared to non-asthmatic FB cells. Consistent with this observation, exposure of profibrotic mediator TGF-β1 effectively reduced the expression of KISS1R in non-asthmatic FB. Furthermore, TGF-β1 exposure significantly increased the α-SMA expression in human FB cells, a myofibroblast marker. Treatment with Kp-10 significantly reduced TGF-β1-induced α-SMA expression in FB cells. TGF-β1 stimulation in human FB increased the F-actin formation. Kp-10 significantly attenuated TGF-β1-induced F-actin formation in FB cells. Additionally, chronic TGF-β1 exposure enhanced collagen gel contraction by FBs, while Kp-10 treatment effectively reduced this contraction. Conclusion This study demonstrates that activation of Kp/KISS1R signaling attenuates TGF-β1-induced myofibroblast differentiation in lung FB, suggesting KISS1R as a potential therapeutic target against airway remodeling. This abstract is funded by: NIH grant R01-HL146705 (Venkatachalem)

Abstract Rationale Bronchial airways are exposed to continual mechanical forces such as normal breathing, sighs, and clinically applied pressures such as CPAP that influence airway smooth muscle mechanics. Asthmatic airways experience exaggerated mechanical stress due to bronchoconstriction and airway wall thickening (remodeling) which contributes to lung injury. Mechanical stress is known to alter redox balance and ion channel signaling, yet its impact on iron homeostasis in asthmatic human airway smooth muscle cells (hASMs) remain unclear. Ferroptosis and iron dysregulation have emerged as significant factors in epithelial damage and airway inflammation in asthmatic models. In addition, recently discovered mechanosensitive Piezo (PZ) channels play a critical role in calcium influx upon mechanical stimulation and have been shown to contribute to iron dysregulation. In this study, we used hASMs to test the hypothesis that asthmatic patients experience iron dysregulation in the presence of mechanical stimulation. Methods hASMs and lung tissues from adult male and female patients with/without asthma were used (approved by Mayo IRB). Cells were pretreated with either PZ inhibitor GsMTx4 [1 µM] or PZ1 agonist Yoda1 [10 µM] 45 minutes before stretch. Cells were exposed to normal breathing stretch conditions on a FlexCell System at a 5% cyclic strain (15 cycles/minute) or 10% static stretch superimposed onto normal breathing for 24 hours. Cell lysates were examined for iron accumulation and antioxidant and lipid peroxidation markers (FTH1, TfR1, GPX4, and SLC7A11). Levels of intracellular ferrous iron (Fe2+) were determined using the fluorescent dye FerroOrange in non-stretched samples. Results In healthy airways PZ inhibition decreased iron uptake while activation increased intracellular iron uptake. In healthy airways, mechanical stretch upregulated SLC7A11 expression in a PZ1 independent manner, while mechanical stretch in asthmatic patients displayed no increase in the cysteine transporter. Transferrin levels remained unchanged under mechanical stimulation but displayed upregulation in asthmatic cells. In healthy cells, ferritin showed no changes in response to stretch, however, asthmatic cells showed lower baseline expression and increased its expression in response to stretch in a PZ1 independent manner. GPX4 showed no changes in expression between healthy and asthmatic groups or in response to stretch. Conclusions Our findings suggest that PZ and mechanical stretch play a role in iron regulation in hASMs. Additionally, iron regulation is impaired in asthmatic populations, suggesting a resultant increased iron import, decreased capacity to sequester iron, and decreased defensive cysteine import. This abstract is funded by: NIH R01HL171915 (CMP), R01HL056470 (YSP) 24POST1241979 (NAB)

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 Aim Acute respiratory distress syndrome (ARDS) is a life-threatening condition frequently managed in intensive care units, with high in-hospital mortality. Less is known about where mortality happens once care transitions beyond hospital. This study aimed to assess national trends in the location of ARDS-related deaths in the U.S. from 2003 to 2020 to evaluate racial and ethnic disparities in end-of-life settings. Methods A retrospective analysis was performed using Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) death certificate data from 2003 to 2020 for all decedents with ARDS (ICD-10 code J80) within the U.S. The proportion of deaths by location (medical facility, decedent’s home, hospice facility, nursing home/long-term care, and other/unknown) was calculated for each year. Linear regression was used to evaluate temporal trends in the proportion of deaths across the study period. Odds ratios (ORs) were calculated using 2 × 2 contingency tables to compare the likelihood of dying in a specific location (e.g., hospice facility, medical facility) between racial and ethnic groups. Results There were 29,028 ARDS deaths in the U.S. from 2003 to 2020. The majority (95.52%) of deaths occurred in medical facilities, with smaller proportions at nursing facilities (1.52%), home (1.50%), hospice (0.69%), other locations (0.33%), and unknown (0.43%). There were no significant changes in the proportions of deaths occurring in medical facilities, decedents’ homes, or nursing homes/long-term care facilities (P > .05 for all). However, the proportion of ARDS deaths occurring in hospitals increased significantly among Black (0.73% to 0.78% (P < .03)) and Asian/Pacific Islander patients (0.12% to 0.19% (P < .01)). Black patients had higher odds of dying in a medical facility compared to White patients (OR = 3.44). No ARDS decedents in the Asian or American Indian groups died outside a medical facility, yielding ORs that approached infinity for these groups. Conclusion The location of ARDS deaths in the U.S. remained largely constant from 2003 to 2020, with most patients dying in hospital settings. This highlights the severity of ARDS and its high in-hospital mortality, reflecting that intensive care is typically required for management. Despite advances in supportive therapies, the persistently high rate of in-hospital deaths suggests limited improvements in out-of-hospital transitions. This study also identified racial disparities. Black patients had higher odds of dying in medical facilities compared to White patients, suggesting inequities in access to home-based end-of-life care options. This abstract is funded by: None

Abstract Introduction E-cigarette use has risen dramatically in the past decade, accompanied by recognition of e-cigarette or vaping-use associated lung injury (EVALI). Although increasingly reported, the pathophysiology of EVALI remains poorly defined, and its clinical presentation and diagnostic evaluation are often nonspecific. Clinicians should maintain a high index of suspicion given its varied manifestations. We describe a young patient with EVALI complicated by histopathologic evidence of secondary pulmonary alveolar proteinosis (PAP), progressing to severe hypoxemic respiratory failure that ultimately required bilateral lung transplantation. Case Presentation A 28-year-old man with a nine-year history of vaping nicotine and THC-containing hash oil presented with chronic hypoxemic respiratory failure requiring BiPAP. One year earlier, he developed digital clubbing, followed by progressive cough and exertional dyspnea. Initial chest CT showed diffuse centrilobular ground-glass opacities without septal thickening, thought to represent hypersensitivity pneumonitis. Despite vaping cessation several months prior to presentation, his symptoms progressed rapidly, and he required high-flow supplemental oxygen (Fi02 80% at 50 L/min) within weeks of admission. Bronchoscopy with bronchoalveolar lavage and biopsy demonstrated focal organizing pneumonia, pigmented foamy macrophages, and eosinophilic acellular debris within alveoli, consistent with pulmonary alveolar proteinosis (PAP). Cultures and cytology were negative for infection or malignancy. Autoimmune serologies were unrevealing, and no alternative exposures were identified. Due to worsening hypoxemic respiratory failure and lack of response to vaping cessation, steroids, and nebulized sargramostim (recombinant human granulocyte-macrophage colony-stimulating factor), he underwent bilateral lung transplantation. Whole lung lavage was considered but not pursued due to concern for further deterioration. Explant pathology showed interstitial fibrosis with a nonspecific interstitial pneumonia pattern and extensive PAP-like reaction with cholesterol clefts and small airway injury. Discussion EVALI encompasses a broad spectrum of radiographic and histopathologic findings, but secondary pulmonary alveolar proteinosis (PAP) is rarely reported. Diagnostic criteria include e-cigarette use within 90 days and pulmonary infiltrates or ground-glass opacities, with exclusion of malignant, autoimmune, and infectious causes. Although most often associated with ground-glass opacities and organizing pneumonia with diffuse alveolar damage, the pathology of EVALI is variable and poorly understood, further complicated by heterogeneity in vaping exposures. This case highlights PAP as a potential manifestation of EVALI, raising the possibility that impaired alveolar macrophage function and surfactant clearance contribute to hypoxemia in severe disease. Clinicians should maintain a high index of suspicion for EVALI and be aware of its diverse histopathologic spectrum. Continued research is needed to clarify underlying mechanisms and guide management. This abstract is funded by: None