Allergic bronchopulmonary aspergillosis successfully treated with tezepelumab

Allergic bronchopulmonary aspergillosis (ABPA) is caused by an exaggerated TH2 response to Aspergillus antigens and is characterized by mucus plugging of the airways.1,2 It is thought to be driven by an eosinophil–mucus complex interplay. IL-13 stimulates the epithelium to secrete high levels of mucins, including mucin MUC5AC, into the airway lumen and increases the transport of thiocyanate via pendrin. IL-5 promotes the survival of eosinophils that release eosinophil peroxidase and hydrogen peroxide, which react with thiocyanate to cross-link mucins and stiffen mucus.