Sputum “IL-5, IL-17A, IL-25-high” pattern is associated with uncontrolled asthma and worse lung function

Results The “IL-5-high” asthma profile (n=13) merged with the “IL-25-high” (10/13) and surprisingly also with the “IL-17A-high” (11/13) profile. A sputum “IL-25-high” profile was even restricted to patients with an “IL-5-high” profile. Only a minority of “IL-5-high” patients were found to be “IL-4-high” (n=6), whereas 17 other patients had an “IL-4-high” profile without being “IL-5-high”. Patients with an “IL-5-high”, Il-17A-high” and/or “IL-25 high” cytokine pattern had worse lung function parameters (FEV1%pred., PEF, FEF25-75%). Uncontrolled asthmatics had significantly higher sputum IL-5, IL-17A and IL-25 mRNA levels. Conclusion Airway cytokine expression is highly heterogeneous amongst patients and their exact contribution to asthma pathogenesis is debated. Uncontrolled asthma was associated with higher levels of IL-5, IL-17A and IL-25 in the airways of asthmatics. Identifying patients’ aberrant cytokine expression in the airways by non-invasive techniques might help to define responders to current and future therapies.