Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A in pre-defined groups of adult patients with moderate and severe bronchial asthma.
BACKGROUND
Bronchial asthma (BA) is a complex disease characterised by persistent inflammation. Exhaled nitric oxide (FeNO) and blood eosinophil count (b-Eos) are biomarkers for type 2 endotype of BA.


OBJECTIVE
To analyse a panel of serum interleukins and total IgE in predefined by FeNO and b-Eos groups of moderate and severe BA patients.


METHODS
Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A (ELISA) were measured in 30 healthy controls (HC) and 80 adult BA patients. BA patients were split into 4 groups. Group 1:Low FeNO/Low b-Eos (n = 23; 28.8%); Group 2:Low FeNO/High b-Eos (n = 17; 21.3%); Group 3:High FeNO/Low b-Eos (n = 15; 18.8%); Group 4:High FeNO/High b-Eos (n = 25; 31.3%).


RESULTS
All interleukins and total IgE were significantly higher in patients with BA as compared with HC. IL-5 levels were highest in Group 2 (p < 0.05). IL-6, IL-13 and IL-17A levels were elevated in Groups 2, 3 and 4 as compared with HC (p < 0.05). Higher IL-8 levels were associated with a pattern of current smokers. Highest IL-17A levels were found in type 2 high groups with frequent exacerbations, mostly uncontrolled and severe BA. We have found a distinct pattern for each group based on demographic, clinical, functional, immunological and inflammatory characteristics.


CONCLUSION
FeNO and b-Eos are useful in the identification of severe type 2 BA subgroups with frequent exacerbations. IL-5, IL-6, IL-13 and IL-17A are involved in the persistent type 2 immune response in moderate and severe BA. We have identified a pattern of refractory, severe type 2/IL-17A high BA in the real clinical practice.
['Dimitrova|Denitsa|D|', 'Youroukova|Vania|V|', 'Ivanova-Todorova|Ekaterina|E|', 'Tumangelova-Yuzeir|Kalina|K|', 'Velikova|Tsvetelina|T|']
D000328:Adult D001249:Asthma D015415:Biomarkers D016022:Case-Control Studies D004804:Eosinophils D045853:Exhalation D005260:Female D006801:Humans D007073:Immunoglobulin E D007249:Inflammation D018793:Interleukin-13 D020381:Interleukin-17 D015848:Interleukin-5 D015850:Interleukin-6 D016209:Interleukin-8 D007958:Leukocyte Count D008297:Male D008875:Middle Aged D009569:Nitric Oxide D012720:Severity of Illness Index
IL-5 IL-6 IL-8 IL-13 IL-17A Moderate and severe asthma