Chapters authored
Noninvasive Biomarkers of Asthma
Asthma is a heterogeneous disease of the lower airways including various types of bronchial inflammation presenting with different phenotypes and endotypes. Therapeutic response of asthmatic phenotypes/endotypes can be predicted by the use of biomarkers of inflammation phenotyping, and in recent years, endotyping of asthmatics allows to predict who will best respond to anti-inflammatory treatment and optimize quality of life of asthmatics by reducing the risk of exacerbations. Based on noninvasive biomarkers of inflammations, several of them have been described that are useful in clinical practice. Some of the noninvasive biomarkers have a particularly important role in the diagnosis and treatment of asthmatics. Monitoring of noninvasive biomarkers, such as fraction of exhaled nitric oxide (FENO), cells in sputum, or biomarkers in exhaled breath condensate (EBC), two main inflammatory phenotypes have been described: eosinophilic phenotype and neutrophilic phenotype. In eosinophilic asthma, as the most prevalent inflammatory phenotype, asthmatics have more than 3% eosinophils in the sputum, elevated levels of FENO, and elevated leukotriene’s cytokine levels in EBC. The most extensively studied biomarkers in asthma are TH2 or more generally T2-related asthmatic endotype. Their clinical benefit might be used to phenotype/endotype features of the underlying type of inflammation and selection of asthmatics, particularly with severe or difficult-to-treat asthma, which most likely will respond to additional biological therapy. In this chapter, we summarize the noninvasive biomarkers available for the management of asthmatics.
Part of the book: Asthma Diagnosis and Management