Cool Science in Identifying Asthma Phenotypes
Like many of you, I am always excited when asthma research moves a bit closer to its goals. This is especially as a patient if it may eventually be able to benefit you from what researchers are learning. In a recent study that was published in CHEST, researchers have learned that airway periostin is both measurable and increased in patients with severe asthma. This was found to be linked to those asthmatics that have the T2 endotype.1
What is T2 endotype of asthma?
A T2 endotype of asthma indicated the underlying mechanism of inflammation of T-helper type 2 (Th2) inflammation, which is mediated by Il-4, Il-5, Il-13 pathways.4 You may have heard about these related cytokines in relation to their emerging treatments that have recently come to the forefront. In particular, in relation to biologics which are targeting these pathways.
What is airway periostin and what is it's role in severe asthma?
Periostin is a systemic biomarker of eosinophilia in asthmatics.3 It is important in airway inflammation as it is involved in the recruitment of eosinophils in the airways. While not everything is in the know, its current claim to fame is that it is helping identify patients that will be treatment-responsive to targeted biologic agents. Periostin can be found in areas inside and outside of the lungs. However, the study in CHEST looked specifically at serum periostin which is found inside the airways as a biomarker. Serum periostin can be measured and it is thought that patients with higher levels of periostin have more severe asthma that is likely correlated with Th2 inflammation. It is important to note that the entire mechanics is not yet known about periostin trafficking into the airways however this is an area of active research.2 The subjects in the study underwent exhaled breath condensate (EBC) and sputum collection, eosinophil count in blood, fractional exhaled nitric oxide, and IgE measurement. Periostin was assessed by an enzyme-linked immunosorbent assay kit on EBC and induced sputum (IS) supernatant to determine the correlations.1 Many of these tests are routinely available and will help identify hopefully in a more efficient way.
"What is your asthma endotype?"
Can you imagine a time in the near future, where we asthmatics go around a dinner party asking each other, “Hey, what is your endotype?” This research points to steps forward helping to provide more targeted treatment to patients but also develop a better understanding of what factors are driving asthma. I used to sit in waiting rooms hoping that I could find some asthma peeps with the same or similar endotype, who were experiencing the same things that I was. We may indeed be one step closer.
Do you get muscle cramps caused by your asthma medicine?