Systemic and breath biomarkers for asthma: an update

Abstract

Purpose of review Finding suitable biomarkers to phenotype asthma, identify individuals at risk of worsening and guide treatment is highly prioritized in asthma research. We aimed to provide an analysis of currently used and upcoming biomarkers, focusing on developments published in the past 2 years. Recent findings Type 2 inflammation is the most studied asthma mechanism with the most biomarkers in the pipeline. Blood eosinophils and fractional exhaled nitric oxide (FeNO) are those most used clinically. Recent developments include their ability to identify individuals at higher risk of exacerbations, faster decline in lung function and more likely to benefit from anti-IL-5 and anti-IL-4/-13 treatment. Certain patterns of urinary eicosanoid excretion also relate to type 2 inflammation. Results of recent trials investigating the use of serum periostin or dipeptidyl peptidase-4 to guide anti-IL-13 therapy were somewhat disappointing. Less is known about non-type 2 inflammation but blood neutrophils and YKL-40 may be higher in patients with evidence of non-type 2 asthma. Volatile organic compounds show promise in their ability to distinguish both eosinophilic and neutrophilic asthma. Summary The ultimate panel of biomarkers for identification of activated inflammatory pathways and treatment strategies in asthma patients still lies in the future, particularly for non-type 2 asthma, but potential candidates are available.

Multimorbidity in asthma, association with allergy, inflammatory markers and symptom burden, results from the Swedish GA2LEN study

“…eosinophilic inflammation, asthma, rhinitis and atopic dermatitis separately, but no group differences between individuals with asthma and asthma and rhinitis have been observed. 16,17…”

“…1,15 Periostin has been linked to asthma, rhinitis and eczema separately, although no group difference has been observed when comparing subjects with asthma with those with asthma and rhinitis. 16,17…”

Can serum periostin, YKL‐40, and osteopontin levels in pre‐school children with recurrent wheezing predict later development of asthma?

“…8 Because clinical parameters have been insufficient in predicting asthma, several studies have been performed on the biomarkers involved in the pathophysiology of asthma. 9 Periostin, osteopontin, and YKL-40 (also known as chitinase-3-like protein-1) are among these biomarkers studied in children with asthma. 10 Studies in children mostly focused on determining the relationship between biomarkers and asthma severity and phenotype.…”

Treatable Mechanisms in Asthma

“…Unfortunately, it is still true that most guideline-associated definitions include inflammation as a key characteristic, but without indication of specific inflammatory biomarkers [40], while it is widely accepted that the use of biomarkers reflecting activation of these different pathways is a high priority in applying precision medicine in asthma [41]. Undoubtedly, there is a need for reliable biomarkers that allow the identification of activated inflammatory pathways and treatment strategies in asthma patients.…”