Eosinophilic Bronchiolitis Diagnosed by a Transbronchial Lung Cryobiopsy and Successfully Treated with Biologic Agents: A Report of Two Cases and Literature Review.

Eosinophilic bronchiolitis (EB) is a rare airway disease characterized by eosinophilic bronchiolar inflammation. We herein report two cases of EB diagnosed by a transbronchial lung cryobiopsy (TBLC), a less invasive diagnostic procedure than a surgical biopsy. Two patients with a history of refractory asthma responded to treatment with oral corticosteroids and biologic agents. To our knowledge, these are among the first reported cases of EB that were successfully managed with dupilumab and benralizumab. These cases underscore the diagnostic utility of TBLCs and suggest the potential use of biologic agents as corticosteroid-sparing options for EB.