Expiratory flow limitation in a cohort of highly symptomatic COPD patients

The question addressed by the study Small airway collapse during expiration, known as expiratory flow limitation (EFL), can be detected using oscillometry and is associated with worse clinical outcomes in COPD. This study investigated the prevalence of EFL in a cohort of highly symptomatic patients, evaluated clinical and lung function characteristics of patients with EFL and studied the repeatability of EFL over 6 months. Materials/patients and methods 70 patients were recruited. Clinical characteristics and lung function metrics were collected at baseline and 6 months. Impulse oscillometry was used to detect the presence of EFL. Patients were defined as EFLHigh (change in reactance measured at 5 Hz (ΔX5) ≥0.28 kPa·L−1·s−1); EFLIntermediate (ΔX5 0.1–0.27 kPa·L−1·s−1) and EFLNone (ΔX5 <0.1 kPa·L−1·s−1). Results EFLHigh was present in 47.8% of patients at baseline. ΔX5 showed excellent repeatability over 6 months (ρ=0.78, p<0.0001, intraclass correlation coefficient (ICC) 0.88), with the best repeatability observed in EFLNone and EFLHigh patients (ICC 0.77 and 0.65, respectively). Compared to EFLNone patients, EFLHigh had a higher body mass index, worse health-related quality of life and increased peripheral airway resistance. EFLIntermediate was more variable over time with less severe physiological impairment. Answer to the question Overall, these data indicate that EFLHigh is a common, and relatively stable, component of disease pathophysiology in highly symptomatic COPD patients. EFLHigh was also associated with worse quality of life and obesity

Airway Bacteria Quantification Using Polymerase Chain Reaction Combined with Neutrophil and Eosinophil Counts Identifies Distinct COPD Endotypes

From MDPI via Jisc Publications RouterHistory: accepted 2021-09-22, pub-electronic 2021-09-27Publication status: PublishedFunder: AstraZeneca; Grant(s): ESR-16-11869Background: Chronic obstructive pulmonary disease (COPD) inflammatory endotypes are associated with different airway microbiomes. We used quantitative polymerase chain reaction (qPCR) analysis of sputum samples to establish the bacterial load upper limit in healthy controls; these values determined the bacterial colonisation prevalence in a longitudinal COPD cohort. Bacteriology combined with sputum inflammatory cells counts were used to investigate COPD endotypes. Methods: Sixty COPD patients and 15 healthy non-smoking controls were recruited. Sputum was analysed by qPCR (for Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Psuedomonas aeruginosa) and sputum differential cell counts at baseline and 6 months. Results: At baseline and 6 months, 23.1% and 25.6% of COPD patients were colonised with H. influenzae, while colonisation with other bacterial species was less common, e.g., S. pneumoniae—1.9% and 5.1%, respectively. H. influenzae + ve patients had higher neutrophil counts at baseline (90.1% vs. 67.3%, p 0.01), with similar results at 6 months. COPD patients with sputum eosinophil counts ≥3% at ≥1 visit rarely showed bacterial colonisation. Conclusions: The prevalence of H. influenzae colonisation was approximately 25%, with low colonisation for other bacterial species. H. influenzae colonisation was associated with sputum neutrophilia, while eosinophilic inflammation and H. influenzae colonisation rarely coexisted

ERS International Congress 2023:highlights from the Airway Diseases Assembly

In this review, early career and senior members of Assembly 5 (Airway Diseases, Asthma, COPD and Chronic Cough) present key recent findings pertinent to airway diseases that were presented during the European Respiratory Society International Congress 2023 in Milan, Italy, with a particular focus on asthma, COPD, chronic cough and bronchiectasis. During the congress, an increased number of symposia, workshops and abstract presentations were organised. In total, 739 abstracts were submitted for Assembly 5 and the majority of these were presented by early career members. These data highlight the increased interest in this group of respiratory diseases.</p

Type 2 inflammation in eosinophilic chronic obstructive pulmonary disease

From Wiley via Jisc Publications RouterHistory: received 2020-10-12, rev-recd 2020-10-28, accepted 2020-11-11, pub-electronic 2020-12-05, pub-print 2021-06Article version: VoRPublication status: PublishedFunder: NIHR Manchester Biomedical Research Centre; Id: http://dx.doi.org/10.13039/10001465

Sputum neutrophil counts in healthy subjects: relationship with age

A threshold of ∼60% has commonly been used in asthma and COPD studies to define the presence of neutrophilic airway inflammation. This threshold is based on relatively young healthy subject datasets. However, age-related increases in sputum neutrophils have been observed previously. We used a healthy cohort, with a comparatively wider age range, to re-evaluate the age-related increase in sputum neutrophils, analysing changes by decade. We also studied the long-term repeatability of sputum neutrophil counts. Differential sputum cell count data for healthy subjects (n=121) was retrospectively analysed. Subjects with a repeated count (mean interval 4.8 years) were included in longitudinal analysis. There was a significant positive association between age and sputum neutrophil % (rho=0.24, p60%. Sputum neutrophil counts increased with each decade until ∼60 years where a plateau was observed. The baseline sputum neutrophil % increased significantly at repeated sampling (p=0.02), with excellent long-term repeatability (intraclass correlation coefficient=0.80). We confirm previous reports of an age-related increase in sputum neutrophil % in healthy individuals and identified a plateau which occurs at age ∼60 years. There was an increase in sputum neutrophil % during longitudinal follow-up, indicating that age-related neutrophilia is a progressive phenomenon. These findings question the use of an unadjusted threshold, in relation to age, to identify the presence of neutrophilic airway inflammation

Identification of COPD Inflammatory Endotypes Using Repeated Sputum Eosinophil Counts

Higher blood and sputum eosinophil counts are associated with a greater response to corticosteroids in COPD. Low blood eosinophil counts exhibit greater stability over time whereas higher counts demonstrate more variability. Stability of airway eosinophil levels is less well understood. We have studied the stability of sputum eosinophil counts. Differential cell count data for COPD patients (n = 100) were analysed. Subjects with two sputum eosinophil counts, 6 months apart, were included in the analysis. Patients were stratified based on baseline sputum eosinophil count into &lsquo;low&rsquo;, &lsquo;intermediate&rsquo; and &lsquo;high&rsquo; groups: eosinophilLOW (&lt;1%), eosinophilINT (1&ndash;3%) and eosinophilHIGH (&ge;3%). Sputum eosinophil counts showed good stability (rho = 0.61, p &lt; 0.0001, ICC of 0.77), with 67.4% of eosinophilLOW patients remaining in the same category on repeat sampling. Bland&ndash;Altman analysis of the whole cohort (median difference between measurements = 0.00%, 90th percentile = &minus;1.4 and 4.7%) showed greater variation at higher counts. This was confirmed by the wider 90th centiles in the eosinophilINT (&minus;1.50 to 5.65) and eosinophilHIGH groups (&minus;5.33 to 9.80) compared to the eosinophilLOW group (&minus;0.40 to 1.40). The repeatability of sputum eosinophil counts was related to the baseline eosinophil count; sputum eosinophilLOW COPD patients were relatively stable over time, while the eosinophilHIGH group showed greater variability. These results can facilitate the identification of COPD endotypes with differential responses to treatment