[A CASE OF ALLERGIC BRONCHOPULMONARY MYCOSIS WITH NONTUBERCULOUS MYCOBACTERIOSIS SUCCESSFULLY TREATED WITH BENRALIZUMAB FOR STEROID WITHDRAWAL].

A 56-year-old woman who had allergic bronchopulmonary mycosis (ABPM) with nontuberculous mycobacteriosis (NTM) was treated with prednisone. After treatment, her respiratory symptoms, eosinophil count, and infiltrative shadow diminished. However, when the dosage of prednisone was tapered and finally stopped, the eosinophil count increased and the infiltrative shadow returned. Since there was a risk of exacerbation of NTM, benralizumab without prednisone was administrated, which improved the patient's respiratory symptoms and eosinophil count, while the infiltrative shadow remained. When the dosage of prednisone was restarted, the shadow disappeared. After prednisone discontinuation, no exacerbation of the shadows nor relapse were observed. In recent years, clinical usefulness of biologics like benralizumab for ABPM has been reported, but evidence to support their use is insufficient. Furthermore, it is expected that the number of the combined cases of NTM and ABPM will increase with the increase in NTM; however, reports of biologics for the management of both cases are extremely rare. The risk of complications of infectious diseases, interaction with antifungal drugs, and steroid sparing effects should be considered when deciding the treatment strategy. Accumulation of more cases in the future may lead to the establishment of a treatment method for the combined cases of NTM and ABPM.