Background: Anti-IL5 receptor ? is used to reduce the number of exacerbations and improve disease control in T2 severe asthma patients.

Aims and Objectives: To evaluate the effects of anti-IL5 receptor ? on systemic and airway inflammation, disease control, lung function in real life T2 severe asthmatic patients after 12-month treatment.

Methods: A retrospective study has been conducted in our severe asthma centre. A comparison of clinical, functional, and inflammatory (induced sputum eosinophils-SE and blood eosinophils-BE) characteristics were assessed at baseline (T0) and after 12 months of treatment (T12).

Results: 17 patients [median (IQR) age 56 (48.5-61.5) years; 6 (35.3%) males] with severe asthma were enrolled. At T12 after anti IL-5 receptor ? treatment, a significant improvement in FEV1% [median (IQR) (79 (59-101.5) to 93 (79.8-104.0); p=0.006] and FEF 25-75% [median (IQR) 55.0 (32.5-85.5) to 88 (49-104); p=0.036] was observed, with a normalization of the Tiffenau index [median (IQR) 67.8 (57.0-76.7) to 77.1 (67.1-81.1); p=0.011)]. A significant reduction of exacerbations (p=0.001), OCS dose (p=0.005) and Asthma Control Test score was observed (p=0.001). The ability of sputum production was significantly reduced (p=0.031) as well as SE% [median (IQR) 57.1 (13.0-79.9) to 0 (0-0.3); (p=0.018)] and BE count [median (IQR) 620 (270.8-845.7) to 0 (0-0); (p<0.001)] and BE% (p<0.001).

Conclusions: After 12 months of treatment with anti-IL-5 receptor ?, improvement of FEV1% and FEF 25-75%, normalization of Tiffenau index and increase of disease control were accompanied by a significant decrease in the rate of expectoration ability and by a substantial reduction in both systemic and airway eosinophilic inflammation.