New inflammatory pathways in asthma: the pathophysiology of asthma revisited

In the same way, the clinical presentation of asthma may differ from one individual to another, it has been demonstrated that the nature and extent of bronchial inflammation in asthma also varies among subjects. Thus, the composition of the bronchial inflammatory infiltrate makes it possible to distinguish at least two molecular signatures, each with a distinct pathophysiology. A "Th2" profile, the most frequent, with increased total E immunoglobulin levels, the presence of eosinophils and "Th2" cytokines (IL-4, IL-5 and IL-13) in the airways. It includes classical allergic asthma related to an abnormal adaptive immune response but also a subtype of non-allergic asthma where eosinophil accumulation is under the control of the innate immune system via a newly identified cell population, called type 2 innate lymphoid cells (ILC2); type 2-driven asthma is thus an emerging nomenclature for a common subtype of asthma. And a "non-Th2" profile, including the accumulation of neutrophils in the airways, with new pathways beginning to be uncovered.