Protected sampling is preferable in bronchoscopic studies of the airway microbiome

The aim was to evaluate susceptibility of oropharyngeal contamination with various bronchoscopic sampling techniques. 67 patients with obstructive lung disease and 58 control subjects underwent bronchoscopy with small-volume lavage (SVL) through the working channel, protected bronchoalveolar lavage (PBAL) and bilateral protected specimen brush (PSB) sampling. Subjects also provided an oral wash (OW) sample, and negative control samples were gathered for each bronchoscopy procedure. DNA encoding bacterial 16S ribosomal RNA was sequenced and bioinformatically processed to cluster into operational taxonomic units (OTU), assign taxonomy and obtain measures of diversity. The proportion of Proteobacteria increased, whereas Firmicutes diminished in the order OW, SVL, PBAL, PSB (p<0.01). The alpha-diversity decreased in the same order (p<0.01). Also, beta-diversity varied by sampling method (p<0.01), and visualisation of principal coordinates analyses indicated that differences in diversity were smaller between OW and SVL and OW and PBAL samples than for OW and the PSB samples. The order of sampling (left versus right first) did not influence alpha- or beta-diversity for PSB samples. Studies of the airway microbiota need to address the potential for oropharyngeal contamination, and protected sampling might represent an acceptable measure to minimise this problem.publishedVersio

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

A pilot study of hot-wire, ultrasonic and wedge-bellows spirometer inter- and intra-variability

Objective: The aim of this pilot study was to compare spirometric values obtained with different types of spirometers, spirometers of same type, and repeated measurements with the same spirometer in a pulmonary function laboratory setting. Results: 12 healthy volunteers performed spirometry on four hot-wire (SensorMedics), two ultrasonic (Spirare) and one wedge-bellows (Vitalograph S) spirometers, according to ATS/ERS (American Thoracic Society/European Respiratory Society) guidelines. Spirometric values were compared using linear mixed models analysis with a random intercept for subjects and a fixed effect for type of spirometer used. Confidence intervals and p values were adjusted for multiple comparisons. Mean ± SD (L) values for hot-wire, ultrasonic and wedge-bellows spirometers for FVC (forced vital capacity) were 4.02 ± 0.66, 3.69 ± 0.61 and 3.93 ± 0.69, and for FEV1 (forced expiratory volume in one second) 3.06 ± 0.44, 2.95 ± 0.44 and 3.10 ± 0.49. Significant differences were found between hot-wire and ultrasonic and between wedge-bellows and ultrasonic spirometers for FVC and FEV1, and between hot-wire and wedge-bellows spirometers for FVC but not for FEV1. There were no significant differences between spirometers of same type, and low mean differences in repeated measurements for all spirometers included. In conclusion, the pilot study shows systematically higher values for FVC and FEV1 for hot-wire and wedge-bellows compared to ultrasonic spirometers