Characteristics of Type 2- High Inflammatory Endotype of Asthma Using New Biomarkers From Peripheral Blood and Exhaled Air and Its Effect on the Outcome of Therapy

According to WHO, asthma bronchiale (AB) is the most frequent non-infectious disease in adults. There are 340 million patients with AB in the world. Approximately 500 000 patients in the Czech Republic are suffering from AB and 2,1 % have severe AB with the indication for conventional anti-inflammatory treatment. This subgroup of patients represents significantly high costs for the healthcare system. There are many clinical phenotypes and molecular endotypes of AB and each of these groups has a different response to treatment. In the Czech republic is recommended classification into two main groups: eosinophil AB (type 2- high) and non-eosinophil AB (type 2- low). Eosinophil AB is furthered classified into two groups: eosinophil allergic (Th2-high) and eosinophil non-allergic (ILC2-high). New biologicals, indicated for patients with the most severe form of AB, have entered the market during the last 15 years. These biologicals have confirmed their potential in randomized controlled studies. It can be assumed that there are 4 000 - 5000 patients suffering from this type of AB who could be indicated to this treatment in the Czech republic but, unfortunately, only 10 % of them have the access to such therapies in real practice. Recommended markers of type 2- high AB don´t have strictly set critical values that are often unspecific, unstable in time, and often affected by other diseases or treatments. Some of the widely accepted predictors of response to biological treatment are eosinophilia, allergic reactivity, level of total and allergic-specific IgE, NO production in inhaled air (FeNO), gender, number of previous exacerbations, and duration of disease. Some of these predictors are used as decision criteria also in Global Initiative for Asthma (GINA) guidelines. With respect to these facts, enormous efforts are being made worldwide to search for new biomarkers, which would be reliable, valid, easily measurable, interpretable, and useful for a more accurate description of the pathogenetic processes of asthma