Aksamit, T.R.

Abstract Rationale Blood eosinophil count (BEC) has emerged as a marker of inflammatory endotypes in bronchiectasis. We examined whether bacterial and mold respiratory culture profiles differ by BEC, comparing patients with BEC ≥300 cells/μL to those with lower BEC. Methods We analyzed patients with bronchiectasis evaluated at a specialized clinic (2019-2025) who had contemporaneous respiratory bacterial and fungal cultures and BEC. Patients were stratified by BEC <300 vs ≥ 300 cells/μL; those with BEC <300 were further subclassified (<100 and 100-299 cells/μL) for figure presentation only. Cultures were evaluated for overall growth and organism-specific prevalence across eosinophil strata, focusing on the most frequently isolated organisms. Group comparisons were performed using Fisher’s exact test. Results A total of 608 patients met inclusion criteria (median age 69 years [IQR 61-77], 72% female); 138 (22.7%) had BEC ≥300 cells/μL. Bacterial growth occurred in 277 patients (45.6%) and mold growth in 366 (60.2%). The odds of bacterial growth were similar between BEC ≥300 and <300 groups (47.1% vs 45.2%). In contrast, BEC ≥300 was associated with higher odds of mold growth (68.1% vs 58.0%; OR 1.54, p = 0.038). Pseudomonas species (18.9%) were the most common bacterial isolates and comprised a greater proportion of all bacterial isolates in patients with BEC ≥300 compared with lower BEC (44.7% vs 30.0%; OR 1.89, p = 0.019). Penicillium species (27.5%), followed by Aspergillus (26.9%), were the most frequently isolated molds, with no differences in distribution across BEC strata. Conclusions BEC ≥300 cells/μL was associated with increased odds of respiratory mold growth and enrichment of Pseudomonas species, suggesting that eosinophil-defined endotypes may identify patients with distinct airway microbiologic patterns that could inform future phenotyping and treatment strategies. This abstract is funded by: None

Abstract Introduction Bronchiectasis is a chronic respiratory disease that increases fatigue, disability, and impairs quality of life. However, the impact of fatigue on patients with bronchiectasis, even in short-term follow-up, has not been sufficiently examined. We explored the association between fatigue and clinical outcomes among patients with bronchiectasis. Methods Adult bronchiectasis patients enrolled in the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry were retrospectively analyzed. Patients with at least one annual follow-up visit in the 3-5 years post baseline and with fatigue data at both baseline and follow-up were included. Patients were grouped as experiencing fatigue versus not experiencing fatigue in the 2-years prior to baseline as reported at their baseline visit. We explored the relationship between baseline fatigue with patient demographics, co-existing conditions, components of the modified bronchiectasis severity index at baseline and follow-up. Wilcoxon, chi-square, and Fisher’s exact tests were used to assess the differences in continuous variables and associations between categorical variables, respectively. Stepwise multivariable logistic regression models explored the relationship of baseline fatigue with exacerbations and hospitalizations at follow-up. Model selection predictors were evaluated based on clinical relevance or p < 0.05 in univariable analyses. Results 1265 adults with bronchiectasis met the inclusion criteria. 563(45%) reported experiencing fatigue and 702 (55%) did not. The median age (interquartile range) was 70(62-78) years and patients were predominantly female (n = 1042, 83%). At baseline, patients experiencing fatigue had a higher proportion of co-existing diagnoses such as gastroesophageal reflux disease, chronic obstructive pulmonary disease, and rheumatologic disease, compared to those without fatigue (all p < 0.05). Furthermore, patients with fatigue had a higher prevalence of pulmonary-related hospitalizations (p < 0.001) at baseline and follow-up. Pseudomonas aeruginosa colonization and elevated dyspnea (modified Medical Research Council [mMRC] grade≥1) were more prevalent among those experiencing baseline fatigue compared to those without (all, p < 0.05). History of prior exacerbations (Odds Ratio [OR]:1.67, 95% CI:1.17-2.41) and baseline Pseudomonas aeruginosa colonization (OR:1.22, 95% CI:1.01-1.47) were significantly associated with increased odds of exacerbations at follow-up. In multivariable stepwise logistic regression, there was an increased odds of at least 1-hospitalization at follow-up among males (OR:2.23, 95% CI 1.12-4.42), patients with decreased Body Mass Index (OR:0.93, 95% CI: 0.87-1.0), and among patients with elevated dyspnea (mMRC grade ≥1) at baseline (OR:2.22, 95% CI: 1.16-4.24),[Table 1]. Conclusions Fatigue in bronchiectasis patients is associated with a more severe disease and greater healthcare utilization, although it may not independently predict future exacerbations or hospitalizations when accounting for other factors. This abstract is funded by: Bronchiectasis and NTM Association

Abstract Background Sputum color is a visual marker of airway inflammation and disease activity in bronchiectasis, ranging from clear or light gray (mucoid) to yellow-green (purulent), the latter largely reflecting neutrophil myeloperoxidase release. This study evaluated associations between sputum color and common clinical markers of disease activity to determine which parameters differed most between color categories. Methods Forty spontaneous sputum samples were analyzed from 80 consecutive adults with non-cystic fibrosis bronchiectasis (median age 70 years [IQR 12]; 74% female) enrolled between January 2024 and April 2025 in an observational study. Sputum color was graded using the Murray Sputum Color Chart and classified as mucoid (color #1) or purulent (colors #2-4). Clinical parameters, including blood cell counts, C-reactive protein (CRP), fractional exhaled nitric oxide (FeNO), and results of bacterial and acid-fast bacillus cultures (induced or bronchoscopic), were obtained from medical records if available within one month of enrollment. Categorical variables were analyzed using chi-square or Fisher’s exact tests and continuous variables with the Mann-Whitney U test. A secondary analysis compared patients who could versus could not produce spontaneous sputum. Results Of 40 samples, 20 (50%) were purulent. Blood neutrophil counts (median 4.5 vs. 3.9 x109/L), neutrophil-to-lymphocyte ratios (2.5 vs. 2.6), and eosinophil counts (1.7 vs. 1.7 x109/L) did not differ significantly between groups (n = 26). FeNO was normal in all 10 patients with available data and was not analyzed further. CRP was higher among patients with purulent sputum (4.6 vs. <3 mg/L; n = 20; p = 0.044). Bacterial growth was more frequent in purulent than mucoid samples (73% vs. 31%; n = 31; p = 0.032). Isolates in the purulent group included Klebsiella, Pseudomonas, Staphylococcus, and Streptococcus (n = 2 each), and single isolates of Acetobacter, Acinetobacter, Chryseobacterium, Delftia, Enterobacter, Escherichia, and Moraxella. In the mucoid group, Pseudomonas, Staphylococcus (n = 2 each), and Stenotrophomonas (n = 1) were identified. Mycobacterial growth did not differ significantly (20% vs. 12.5%; n = 31; p = 0.65). Patients unable to produce spontaneous sputum had a higher rate of mycobacterial isolation on induced/bronchoscopic samples (43% vs. 16%; n = 54; p = 0.027), though other parameters were similar. Over 90% of measurements were obtained within three days of enrollment, and freezing did not appear to alter sputum color. Conclusions Even within a small cohort, purulent sputum was associated with higher CRP and greater bacterial growth, supporting sputum color as a rapid, inexpensive marker of disease activity in bronchiectasis. Further research should clarify whether sputum color primarily reflects bacterial colonization, airway inflammation, or both. This abstract is funded by: None

Abstract Rationale: Chronic lung diseases, such as COPD and bronchiectasis (BE), may manifest differently by gender in symptom presentation, time to diagnosis, and overall disease burden. This study aimed to assess perceptions of individuals with self-reported COPD, BE, or non-tuberculous mycobacteria (NTM) regarding healthcare experiences and disease-related symptoms. Methods: This cross-sectional study analyzed data from US-based and international participants with self-reported COPD, BE, or NTM using an online survey. Participants were recruited through the COPD Foundation (COPDF) social media channels and completed a questionnaire developed with input from a steering committee that included COPDF leadership, physician-researchers, and patient stakeholders. The survey explored participants’ experiences with healthcare, disease burden, and self-reported symptoms. A subset of women answered additional questions regarding menopause-related symptom changes. Descriptive statistics were calculated and analyzed across self-identified genders and two disease groups: COPD (with or without BE or NTM) and BE (with or without NTM or COPD). Continuous variables were compared using ANOVA, while categorical variables were analyzed using chi-square or Fisher's exact test. Results: Of 632 respondents included in these analyses (mean age 70±9 years, 74% women), 68% reported COPD and 32% BE (both groups included individuals with or without additional diagnoses). Women with COPD were younger than men (p=0.048) and had a shorter duration between symptom onset and initial healthcare visit (< 6 months) (p<0.01). Compared to men, a higher proportion of women with COPD reported that their diagnosis was not explained by a healthcare provider (p=0.0381) and that they experienced anxiety, depression, or fear related to their diagnosis (p=0.0074). Among participants with BE, men and women were similar in age, though a higher proportion of men had shorter intervals (<6 months) between initial healthcare visit and confirmed diagnosis (p=0.0244) and received their diagnosis during hospitalization (p=0.0244). Both men and women across diagnoses reported similar levels of disease management burden, pulmonologist visit frequency, CAAT scores, numbers of comorbidities, and financial difficulties related to their lung condition. Over 75% of women identified as post-menopausal, with approximately one-third reporting worsening pulmonary symptoms associated with menopause. Conclusions: Despite similarities in disease management and comorbidity burden, women with BE and men with COPD reported longer times to initial healthcare visits and diagnostic delays, respectively. Additionally, over one-third of post-menopausal women experienced symptom exacerbation since menopause. These findings underscore the need to further explore gender-based differences and disparities in healthcare access and pulmonary care to enhance lung health outcomes across genders.

Abstract RATIONALE: Understanding co-isolation patterns between fungi and other potentially pathogenic microorganisms in the airways of bronchiectasis patients is important for uncovering possible microbial interactions and informing treatment. Although numerous organisms have been identified in respiratory cultures, the specific patterns of their co-isolation are underexplored. OBJECTIVES: To examine the patterns of co-isolation between fungi and bacteria or mycobacteria in respiratory samples from patients with bronchiectasis across a large national health system. METHODS: We reviewed 58,170 respiratory culture tests from 8,194 patients with bronchiectasis (identified using ICD-10-CM codes J47.0, J47.1, and J47.9) across Mayo Clinic. These tests were analyzed for fungal, bacterial, and mycobacterial growth, focusing on co-isolation from the same sample. Chi-square statistics were used to compute p-values. RESULTS: Of all 18,983 samples cultured for fungi, 59% were positive. Of these, 72% yielded yeasts and 40% molds. Among the 11,372 samples cultured for both fungi and bacteria, 681 (6%) showed co-isolation, representing 54% of positive bacterial cultures. The odds of bacterial co-isolation with fungi were 1.4 (95% CI: 1.3-1.6; p < 0.01), driven by yeasts (OR: 1.5, 95% CI: 1.3-1.7; p < 0.01), rather than molds (OR: 1.0, 95% CI: 0.9-1.2; p = 0.8). Pseudomonas species, the most common bacterial isolate, had a higher likelihood of co-isolation with fungi (OR: 1.6, 95% CI: 1.3-1.9; p < 0.01), particularly yeasts (OR: 1.6, 95% CI: 1.4-2.0; p < 0.01). Molds, including those from genera such as aspergillus and penicillium, did not show a significant association with the isolation of pseudomonas. On the other hand, among the 15,859 samples cultured for both fungi and mycobacteria, 1352 (9%) showed co-isolation, representing 62% of positive mycobacterial cultures. Odds of co-isolation were 1.7 (95% CI: 1.5-1.8; p < 0.01). Molds showed a stronger association with isolation of mycobacteria (OR: 1.7, 95% CI: 1.5-1.9; p < 0.01) compared to bacteria, while yeasts also had elevated odds (OR: 1.4, 95% CI: 1.2-1.5). CONCLUSIONS: Distinct patterns of fungal co-isolation with bacteria and mycobacteria have been observed in bronchiectasis, which may influence key aspects of the disease, such as inflammation and mucociliary dysfunction. Advanced metagenomic and immunoprofiling techniques could provide deeper insights into these co-isolation patterns while considering other factors like clinical demographics, previous antibiotic exposure, and disease severity. Understanding whether altering the mycobiome could modify these aspects and improve outcomes remains an important avenue for research.

Abstract Introduction: Cystic fibrosis (CF) is a genetic disorder characterized by defective chloride ion transport, leading to thick mucus production, chronic respiratory infections, and other multisystem involvement. Although CF is often diagnosed in childhood, the condition can be missed or misdiagnosed in adults. Description of Case: We present the case of a 60-year-old male from India who was diagnosed with CF after a prolonged period of sinopulmonary symptoms. He initially presented in 2014. His medical history was pertinent for asthma, and multiple episodes of clinically and radiographically confirmed pneumonia and polypoid sinusitis requiring IV antibiotics and sinus surgery. He carried a prior diagnosis of allergic bronchopulmonary aspergillosis treated with itraconazole and steroids, as well as elevated IgE levels. His CT chest was notable for extensive bronchiectasis, bronchial wall thickening, and mucus plugging of both lungs. He had no known family history of CF. Sweat chloride testing was in the intermediate range (44, 47 mmol/L; normal <30 mmol/L, intermediate 30 to 59 mmol/L, abnormal >59 mmol/L). Given high suspicion for CF, cystic fibrosis transmembrane conductance regulator (CFTR) full gene analysis was pursued. Sequence analysis and multiplex ligation-dependent probe amplification of the CFTR gene detected heterozygous sequence changes c.1717-2A>T, classified as likely deleterious, and c.1367T>C (p.V456A), variant of uncertain significance. He was thus initially diagnosed as a CF carrier. He re-presented in 2024 with decline in pulmonary function testing and continued sinopulmonary infections. Genetic testing results from 2014 were re-analyzed. Between initial presentation and present, his V456A variant was upgraded to pathogenic. He met diagnostic criteria for CF with two pathogenic CFTR variants, a repeated intermediate sweat chloride (47 mmol/L) suggestive of CFTR protein dysfunction, and disease that could be attributed to CFTR dysfunction. He subsequently started TRIKAFTA® (elexacaftor/tezacaftor/ivacaftor and ivacaftor) and airway clearance therapy. Discussion: The diagnosis of CF in adults can be challenging, particularly in individuals without a known family history, intermediate sweat chloride testing, and with inconclusive genetic testing. Our understanding of CF in Asian populations is limited. CF is suspected to be underreported in patients with Southeast Asian ancestry in part due to genetic heterogeneity. The interpretation of certain genetic variants can evolve over time. A variant of unknown significance may later be reclassified as pathogenic, revealing its true role in disease development. This highlights the critical importance of regularly re-evaluating genetic test results.

Abstract RATIONALE: Absolute Blood Eosinophil Counts (BEC) in bronchiectasis patients offer insights into inflammatory patterns and potential treatments. In non-cystic fibrosis bronchiectasis (NCFB), BEC≥300 cells/μL characterizes Eosinophilic Bronchiectasis (EB), a type-2 inflammation endotype estimated in 20% of patients. Guidance on BEC assessment strategy (i.e., number, frequency and timing of BEC≥300 defining this endotype) is unclear. We hypothesize that EB incidence varies by BEC≥300 assessment strategy. We also investigate eosinophilic inflammation in CF for comparison. Objectives: Assess BEC≥300 incidence in NCFB and CF cohorts. METHODS: From January 2023 to October 2024, BEC were measured in 9,953 stable bronchiectasis patients across Mayo Clinic, including 9,806 with NCFB (J47.9; 66,780 CBCs) and 147 with CF (E84.0; 1,405 CBCs). Incidence of BEC≥300 was evaluated in relation to CBC frequency and timing (i.e., BEC≥300 on first, second, last, any, any two, first two simultaneously) and the number of CBCs per patient. RESULTS: In the NCFB cohort, median age was 74 years (IQR:66-82), with 59.5% female. Median CBCs/patient was 3 (IQR:1-7). Incidence of BEC≥300 on the first CBC was 19.8%. Among patients with ≥2 CBCs (n=7,075), incidence was 20.1% on the first, 19.8% on the second, and 20.0% on the last. This incidence rose to 36.3% when considering any CBC/patient. BEC≥300 on at least two CBCs was 29.3%, decreasing to 11.8% when considering consecutive BEC≥300 on both first and second CBCs. The incidence of BEC≥300 increased linearly with the number of CBCs obtained: 24.6% for those with 1-3 CBCs, up to 64.6% for >12 CBCs. In the CF cohort, median age was 36 years (IQR:27-52), with 55.1% female. Median CBCs/patient was 4 (IQR:2-8). BEC≥300 was present in 22.9% of first CBCs, rising to 36.3% when considering any CBC and 29.3% when present on at least two CBCs. Similar to the NCFB cohort, incidence increased with the number of CBCs: 26.5% for 1-3, up to 77.3% for >12. CONCLUSIONS: The incidence of BEC≥300 in our NCFB cohort remained steady at 20% at any specific measurement point, consistent with prospective literature. However, nearly half of those with BEC≥300 on the first or second CBC did not meet this threshold on both. Incidence significantly increased when any CBC was considered, and more CBCs were available. Similar observations were made in the CF cohort. Clearer BEC assessment strategies are needed to define clinically significant eosinophilic inflammation in bronchiectasis, to better identify patients who may most benefit from type 2 inflammation-targeted treatments.

Abstract Introduction: Non-Cystic Fibrosis Bronchiectasis (NCFB) is an obstructive pulmonary disease associated with structural lung disease, altered mucociliary clearance, hyper mucus secretion, recurrent infection, and airway inflammation that results in significant morbidity and mortality. Aspergillus sp (Asp) is a common fungi isolated in respiratory specimens of those with lung disease and is associated with both infectious and allergic pulmonary diseases such as Asthma and Cystic Fibrosis. Despite individuals with NCFB having similar phenotypes as these conditions, the impact of Asp on this population is poorly understood. Methods: We performed a cross-sectional retrospective analysis from the US Bronchiectasis and NTM Research Registry (BRR). NCFB patients without a history of lung transplant who had at least one respiratory Asp culture were included. We compared patients with no history of Asp grown from respiratory culture to those with at least one positive respiratory culture for Asp during the available period. Patient demographics, bacterial culture history, lung function, comorbidities, modified Bronchiectasis Severity Index (mBSI), and sputum parameters were analyzed descriptively. Comparisons between groups were conducted using Kruskal-Wallis, independent sample t-tests, and chi-square tests for continuous and categorical variables as appropriate. Results: 3985 people with NCFB met inclusion criteria. 3359 (84.3%) individuals were Asp culture negative compared to 626 (15.7%) individuals with Asp. There were notable differences in race, showing higher proportions of non-Hispanic white (90.4 vs 82.2%) in this population. While the frequency of Chronic Obstructive Pulmonary Disease and Primary Ciliary Dyskinesia were similar, there were more individuals with Asthma (31.3 vs 24.7%, p<0.001) and Allergic Bronchopulmonary Aspergillosis (ABPA) (6.4 vs 2.4%, p<0.001) in the Asp positive group (Figure 1A). The Asp positive group had higher blood eosinophils (150.0 vs 124.0 cells/uL, p=0.026, Figure 1B), had nominally lower lung function (73.5 vs 75.3% ppFEV1, p=0.089), and were more likely to have at least one or more positive bacterial cultures (62.9 vs 51.9%, p<0.001, Figure 1C). There was no significant difference in sex, age, exacerbations, Pseudomonas aeruginosa or NTM positive cultures, sputum volume, or mBSI. Conclusion: Individuals with NCFB and history of one or more positive Asp cultures were more likely to be non-Hispanic white, have a diagnosis of Asthma and/or ABPA, higher blood eosinophils, and more positive airway bacterial cultures. Further work is needed to better understand how Asp contributes to bronchiectasis progression. More expansive analysis and multivariant modeling is underway to better understand the impact of Asp in people with NCFB.