T2 inflammation is characterized by elevations in:
- absolute peripheral or sputum eosinophil counts
- levels of IgE (total and allergen-specific)
- fractional exhaled nitric oxide (FeNO)
The 3 above serve as biomarkers of T2 inflammation.
T2 inflammation is mediated by key cytokines:
- IL-4
- IL-5
- IL-13
- thymic stromal lymphopoietin
- IL-25
- IL-33
IL-4 and IL-13 utilize Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways.
There are biologic therapies targeting these T2 cytokines, reviewed in the article below:
https://www.jacionline.org/article/S0091-6749(22)00840-5/fulltext