Daily Respiratory Research Analysis
Three standout respiratory papers span translational biology, real-world clinical epidemiology, and evidence-based guidance. A mechanistic JACI study links alcohol-induced respiratory reactions in AERD to acquired ALDH2 deficiency driven by IL-4/IL-13 signaling and improved by dupilumab. A Lancet Respiratory Medicine analysis shows that symptom burden independently predicts bronchiectasis exacerbations and identifies similarly strong responders to long-term macrolides as frequent exacerbators. E
Summary
Three standout respiratory papers span translational biology, real-world clinical epidemiology, and evidence-based guidance. A mechanistic JACI study links alcohol-induced respiratory reactions in AERD to acquired ALDH2 deficiency driven by IL-4/IL-13 signaling and improved by dupilumab. A Lancet Respiratory Medicine analysis shows that symptom burden independently predicts bronchiectasis exacerbations and identifies similarly strong responders to long-term macrolides as frequent exacerbators. ECIL-10 provides updated, pragmatic recommendations for community-acquired respiratory viruses in hematologic patients, including RSV strategies.
Research Themes
- Type 2 inflammation driving epithelial metabolic defects and symptom triggers in AERD
- Symptom-guided risk stratification and macrolide therapy in bronchiectasis
- Evidence-based management of community-acquired respiratory viruses in hematologic patients (including RSV)
Selected Articles
1. Reduced aldehyde dehydrogenase 2 in respiratory tract associates with dysregulated alcohol metabolism and respiratory reactions in aspirin-exacerbated respiratory disease.
In a 600-patient AERD cohort, alcohol-induced upper and lower respiratory symptoms were common and associated with worse disease control and higher eicosanoids. Respiratory tract ALDH2 expression was reduced in AERD, downregulated by IL-4/IL-13 in vitro, and increased after IL-4Rα blockade with dupilumab. Findings support an acquired, type 2 inflammation–mediated ALDH2 deficiency causing acetaldehyde accumulation and mast cell activation during alcohol exposure.
Impact: This work unifies clinical observations with a mechanistic pathway linking type 2 cytokines to epithelial alcohol metabolism and symptoms, and shows therapeutic reversibility with dupilumab.
Clinical Implications: Counsel AERD patients regarding alcohol triggers; consider that IL-4/IL-13–targeted therapy (e.g., dupilumab) may mitigate alcohol-induced respiratory reactions and potentially normalize epithelial ALDH2. ALDH2 expression may serve as a biomarker of symptom susceptibility.
Key Findings
- Alcohol-induced upper (79.6%) and lower (45.1%) respiratory symptoms were frequent in AERD and associated with worse sinus/asthma control and higher urinary eicosanoids.
- ALDH2 protein in nasal polyps and ALDH2 transcripts in nasal epithelial cells were lower in AERD than aspirin-tolerant controls.
- IL-4/IL-13 reduced ALDH2 expression in epithelial cultures; dupilumab increased nasal ALDH2 transcripts in vivo and improved alcohol-induced symptoms in most patients.
Methodological Strengths
- Large clinical cohort integrated with tissue transcript/protein data and in vitro cytokine perturbations
- Therapeutic modulation (dupilumab) provides translational evidence of causality
Limitations
- Observational design without randomized allocation to biologic therapy
- Potential confounding by genetic ALDH2 polymorphisms and alcohol exposure quantification not fully detailed
Future Directions: Prospective trials to test whether IL-4Rα blockade reduces alcohol-induced reactions; evaluate ALDH2 as a predictive biomarker and explore local epithelial metabolic reprogramming in AERD.
BACKGROUND: Patients with aspirin-exacerbated respiratory disease (AERD) frequently experience alcohol-induced respiratory reactions, the immunologic mechanism of which remains unknown. Many East Asian patients experience intense alcohol-induced skin flushing, which is due to an alcohol dehydrogenase 2 (ALDH2) polymorphism that leads to impaired alcohol metabolism and acetaldehyde buildup. OBJECTIVE: We sought to determine whether AERD-related alcohol reactions are attributable to ALDH2 deficiency in the respiratory tract. METHODS: AERD patients (N = 600) completed a survey to assess alcohol-induced symptoms and disease severity; urinary leukotriene E
2. Symptoms, risk of future exacerbations, and response to long-term macrolide treatment in bronchiectasis: an observational study.
Across 9,466 registry patients, both prior exacerbations and worse symptom scores independently predicted future exacerbations. Post-hoc pooled RCT analysis showed that highly symptomatic patients with few prior exacerbations had a similar number-needed-to-treat with long-term macrolides as frequent exacerbators. These data support symptom-informed selection for macrolide therapy.
Impact: Findings challenge current criteria limiting macrolides to frequent exacerbators by demonstrating that symptom burden identifies additional responders with similar benefit.
Clinical Implications: Consider incorporating symptom burden (QoL-B-RSS) into risk stratification and macrolide eligibility, alongside exacerbation history, while balancing antimicrobial stewardship and monitoring for adverse effects.
Key Findings
- Symptoms (per 10-point lower QoL-B-RSS) independently predicted future exacerbations (RR 1.10, 95% CI 1.09–1.11).
- Patients with high symptoms but few/zero prior exacerbations had similar 1-year exacerbation counts as frequent exacerbators.
- Number-needed-to-treat with long-term macrolides was similar when selecting by frequent exacerbations (1.45) vs high symptom burden (1.43).
Methodological Strengths
- Large, multicentre, international registry with standardized symptom assessment and 1-year follow-up
- Post-hoc pooled analysis of three RCTs using negative binomial regression to quantify treatment response
Limitations
- Observational registry design susceptible to residual confounding
- Post-hoc nature of pooled RCT analysis; antibiotic resistance and safety not directly assessed by symptom-defined selection
Future Directions: Prospective trials testing symptom-guided macrolide initiation and de-escalation strategies; integrate microbiome/resistance monitoring to optimize stewardship.
BACKGROUND: Previous studies have suggested that daily symptoms are a marker of bronchiectasis disease activity and could therefore identify patients at increased risk of exacerbation. However, international bronchiectasis guidelines recommend long-term macrolide treatment only in patients with three or more exacerbations per year. We aimed to investigate if symptoms independently predict future exacerbations and therefore identify additional responders to long-term macrolide treatment. METHODS: We used data from the EMBARC registry, a multicentre international bronchiectasis database. Baseline symptoms were evaluated with the quality-of-life bronchiectasis questionnaire respiratory symptoms score (QoL-B-RSS), followed-up for at least 1 year, and were related to the future risk of exacerbations. We subsequently conducted a post-hoc pooled analysis of three randomised controlled trials of macrolides (ie, BLESS, BAT, and EMBRACE) in 341 participants with bronchiectasis to determine if baseline symptoms were associated with response to long-term macrolide treatment, using a negative binomial regression model. FINDINGS: 9466 patients from the 19 324 patients included in the EMBARC registry had available QoL-B-RSS assessment at baseline and 1-year follow-up. The median age was 68 years (IQR 58-74), 5763 (60·9%) were female, and 3703 (39·1%) were male. The median Bronchiectasis Severity Index score was 7 (4-10) and Pseudomonas aeruginosa was present in the sputum of 2041 (21·6%) patients within 12-months of baseline. Previous exacerbations (rate ratio (RR) for every additional exacerbation 1·11, 95% CI 1·10-1·12; p<0·0001) and symptoms (RR for every 10 points lower QoL-B-RSS 1·10, 1·09-1·11; p<0·0001) were identified as independent risk factors for future exacerbations. The number of exacerbations during 1-year of follow-up was similar between patients with three or more exacerbations at baseline and average symptom scores (QoL-B-RSS 60-70; RR 1·58, 95% CI 1·48-1·69) and the group with no previous exacerbations but high symptom scores (RR 1·55, 1·41-1·70). The same pattern was observed in the post-hoc analysis of randomised controlled trials, both in the macrolide and placebo groups. The number-needed-to-treat to prevent exacerbations with long-term macrolide therapy was similar for patients selected based on frequent exacerbations (1·45, 95% CI 1·08-2·24) and in those with few previous exacerbations, but high symptom scores 1·43 (1·06-2·18). INTERPRETATION: Our results suggest that symptoms are an independent risk factor for future exacerbations in bronchiectasis. Patients who are highly symptomatic derive a similar benefit from macrolide treatment as patients with a high baseline exacerbation frequency. FUNDING: EU, European Federation of Pharmaceutical Industries and the Associations Innovative Medicines Initiative Inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis Consortium, European Respiratory Society.
3. Community-acquired respiratory virus infections in patients with haematological malignancies or undergoing haematopoietic cell transplantation: updated recommendations from the 10th European Conference on Infections in Leukaemia.
ECIL-10 standardizes infection control, testing, and management of CARVs in hematologic and HCT patients. Recommendations include influenza vaccination and early antivirals, selective use of RSV vaccines per local approval, passive immunization for children <2 years, and ribavirin/IVIG for HCT recipients with severe immunodeficiency. For other CARVs, supportive care and immune optimization are emphasized.
Impact: Provides consensus, up-to-date guidance across multiple CARVs for a highly vulnerable population, addressing testing, prevention, and treatment amid evolving evidence.
Clinical Implications: Implement standardized CARV testing and infection control in hematologic/HCT settings; vaccinate for influenza; consider RSV vaccines per approval; use ribavirin ± IVIG in select HCT patients with severe immunodeficiency; prioritize supportive care and steroid minimization for other CARVs.
Key Findings
- Unified approach to infection control, laboratory testing, and diagnosis for CARVs, including SARS-CoV-2.
- Influenza: recommend seasonal inactivated vaccines and early antivirals; discourage routine antiviral prophylaxis in immunocompromised patients.
- RSV: consider licensed vaccines per local approval; recommend palivizumab or nirsevimab for children <2 years; ribavirin ± IVIG for HCT recipients with severe immunodeficiency.
Methodological Strengths
- Comprehensive literature synthesis across 2014–2024 with multidisciplinary expert consensus
- Actionable, virus-specific recommendations tailored to hematologic/HCT populations
Limitations
- Evidence gaps for RSV vaccines and prophylaxis in adults with hematologic malignancy/HCT
- Several recommendations are based on low- to moderate-quality evidence or expert opinion
Future Directions: Prospective studies of RSV vaccination strategies in hematologic/HCT adults; randomized evaluation of ribavirin ± IVIG algorithms; improved diagnostics and test stewardship for CARVs.
To update recommendations of the 4th European Conference on Infections in Leukaemia (ECIL-4) on community-acquired respiratory virus (CARV) infections published in 2013, we reviewed publications from between Jan 1, 2014, and June 30, 2024 on adenovirus, bocavirus, coronavirus, influenzavirus, metapneumovirus, parainfluenzavirus, respiratory syncytial virus (RSV), and rhinovirus in patients with haematological malignancies or undergoing haematopoietic cell transplantation (HCT), or both. In the current ECIL recommendations (ECIL-10), we outline a common approach to infection control, laboratory testing, and diagnosis for all CARVs (including SARS-CoV-2) and specific management and deferral strategies for CARVs other than SARS-CoV-2. For influenzavirus, seasonal inactivated-vaccines and early antivirals are recommended, whereas routine antiviral prophylaxis is discouraged for immunocompromised patients. For RSV, licensed vaccines can be considered according to local approval, despite scarce evidence for patients with haematological malignancies and those undergoing HCT. Passive immunisation with palivizumab or nirsevimab is recommended for children younger than 2 years, but data are insufficient for pre-exposure or post-exposure prophylaxis, or treatment of older children and adults. Oral ribavirin or intravenous immunoglobulins, or a combination of the two, are recommended for patients undergoing HCT with severe immunodeficiency scores. For other CARVs, recommendations include only supportive care, improving immune functions, correcting hypogammaglobulinaemia, and judicious lowering of corticosteroids. We highlight unmet needs in immunisation and antivirals for reducing CARV-associated morbidity and mortality in patients with haematological malignancies and those undergoing HCT.