Airway Inflammation May Change Airway Microbiome in Severe Asthma Patients

High levels of neutrophils are associated with altered airway microbiomes in patients with severe asthma, according to new research presented at the American Thoracic Society’s 2019 International Conference.

Results of the study were presented by lead researcher Peter Howarth, MD, from the U-BIOPRED research project on Wednesday, May 22.

FOR MORE ATS 2019 COVERAGE, READ MORE...

Machine-Based Tool May Replace Polysomnography for Diagnosing OSA

Asthma May Be Caused By Violence, Health Risk Behaviors

The U-BIOPRED (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes) research project is an ongoing study of children and adults with asthma in Europe. The researchers aim to better understand the different types of asthma and to ensure a better diagnosis and treatment of patients.

Previous analyses of U-BIOPRED data has shown that patients with asthma have an abnormal airway microbiome. This new analysis aimed to examine the potential relationship between the airway microbiome and neutrophilic inflammation in patients with severe asthma.

To conduct this analysis, Dr Howarth and colleagues obtained sputum samples from 4 cohorts of patients: those with severe asthma who do not smoke (n = 97), those with severe asthma who currently smoke or used to smoke (n = 50), those with non-severe asthma who have been treated with steroids (n = 25), and healthy controls (n = 23).

In the end, the researchers found that the level of neutrophils affected the airway microbiome in participants.

“There were reductions in the richness and diversity between severe asthmatics and the 2 control cohorts,” the researchers wrote. “On analysis of the metagenomic profiles, taxa alpha diversity inversely correlated with sputum neutrophil percent. Veillonellaceae, Prevotellaceae, Neisseriaceae, Streptococcaceae, Porphyromonadaceae, and Micrococcaceae were all negatively correlated with percent neutrophils.”

“This study associates an abnormal airway metagenomic profile in severe asthma with neutrophilic airway inflammation,” the researchers concluded. “Further focus is needed to better understand the dynamics of this relationship, as severe neutrophilic asthma remains an important clinically unmet need.”

—Amanda Balbi

Reference:

Howarth P, Bates S, Versi A, et al; U-BIOPRED Study Group. Sputum metagenomic profiling identifies altered airway microbiome in severe asthma linked to neutrophilic airways. Paper presented at: ATS International Conference; May 17-22, 2019; Dallas, TX. https://www.abstractsonline.com/pp8/#!/5789/presentation/12590.