Resolution of daytime and night-time respiratory symptoms but persistent sleep apnea in severe asthma with the add-on of benralizumab

Introduction: The relationship between asthma and obstructive sleep apnea (OSA) is a widely debated topic in the scientific literature with the controversy surrounding the bi-directional nature of the correlation.Case presentation: We report the case of a 59-year-old male being affected by severe allergic eosinophilic asthma and severe OSA (apnea-hypopnea index [AHI] 32 ev·hr-1).  Due to a clinical worsening of asthma (aggravation of dyspnea, chest constriction and night-time respiratory symptoms), despite the optimal therapy for asthma and recurrent administration of systemic corticosteroids, we have added-on treatment with benralizumab (monoclonal anti-interleukin 5 antibody). After eight months, the patient reported an improvement in asthma control (asthma control test [ACT]= 25 points), in pulmonary function and a good control of nocturnal symptoms of both diseases (i.e., wheezing, snoring, etc.). Then, the follow-up polysomnography (PSG) was performed resulting in a high reduction of OSA severity (~18% AHI) even if obstructive events persisted and almost resolution of nocturnal hypoxemia. So, a trial with positive airway pressure (PAP) was proposed to the patient, who declined.Conclusions: In consideration of our experience, we suggest that the nocturnal profile of patients with severe asthma should be always studied by a sleep investigation to prevent the negative effects of interaction with OSA. However, further studies on larger samples are needed to better understand the pathophysiological mechanisms underlying the beneficial effects of benralizumab on obstructive events during sleep.