High local type-2 inflammation is linked to response in severe asthma treated with anti-Interleukin-5 receptor.

Background: Benralizumab is an anti-IL-5 receptor (IL-5R) therapy linked to a huge improvement of the condition of patients with severe eosinophilic asthma. The goal of this study was to identify baseline airway markers of remission and response after anti-IL5R therapy.

Methods: This observational study included 45 patients initiated with an anti-IL-5R. Remission was defined as: no oral corticosteroids intake, no exacerbation, a good asthma control (ACQ <1.5 and/or ACT >19) and a good lung function (FEV1 ≥ 80 % predicted and/or an improvement ≥10 %). Components of remission were also assessed individually to evaluate the response of patients. Sputum levels of mediators implicated in inflammation and remodeling were measured before treatment.

Results: Among the 45 patients, 12 were classified in remission. These patients were younger at baseline, had a lower smoking exposure, better asthma control and quality of life and a higher FeNO compared to the others. Moreover, baseline blood eosinophil counts were similar but sputum IL-6 and IL-8 levels were significantly higher in the non-remission group. Finally, patients who only improved their ACT or ACQ score had higher baseline FeNO values or sputum eosinophil percentage respectively. Those who increased their FEV1 ≥ 10 % presented a higher baseline sputum eosinophil percentage, sputum eotaxin-3 level and a trend for a higher sputum IL-5 level.

Conclusions: High baseline airway T2 markers appeared to be associated with response to anti-IL-5R therapy. Lower sputum IL-6 and IL-8 levels were linked to remission. These results need to be validated in a bigger cohort.