Successful Treatment with Benralizumab for Allergic Bronchopulmonary Aspergillosis That Developed after Disastrous Heavy Rainfall in Western Japan

Abstract

We herein report a 56-year-old woman who developed allergic bronchopulmonary aspergillosis (ABPA) possibly due to fungal exposure after disastrous heavy rainfall in Western Japan in 2018. She was diagnosed with ABPA complicated with asthma, increased peripheral blood eosinophil count, elevation of specific immunoglobulin E for Aspergillus fumigatus, positive Aspergillus fumigatus precipitation antibody reaction test results, and notable chest computed tomography findings. After treatment with benralizumab, her symptoms, peripheral blood eosinophil count, radiological findings, and respiratory function dramatically improved. The administration of benralizumab appears to be an effective treatment strategy for ABPA.

Keywords: Aspergillus fumigatus; allergic bronchopulmonary aspergillosis; benralizumab; bronchial asthma; heavy rainfall.

Figure 1.

Chest X-ray film (A) and computed tomography scans (B) of the patient taken at the time of the diagnosis of bronchial asthma in 2006, and chest radiography findings on admission to our hospital in December 2019 (C). Ground-glass attenuation in both lung fields (especially in the lower fields) was observed on admission, whereas no abnormal findings were observed at the onset of bronchial asthma.

Figure 2.

Computed tomography scans of the patient’s chest acquired on admission to our hospital in December 2019 showed bilateral thickening of the bronchi, ground-glass attenuation, centrilobular nodules, and mosaic attenuation.

Figure 3.

High-attenuation mucus plaque in the left lower lobe was detected in addition to bronchiectasis.

Figure 4.

A bronchoscopic examination showed a mucous plug in the left lower lobe bronchus (B⁸, B⁹, and B¹⁰). Although Aspergillus fumigatus was not cultured in sucking sputum or brushing samples, Charcot-Leyden crystal was detected on a cytological examination.

Figure 5.

Clinical course after admission to our hospital. Benralizumab treatment led to a dramatic improvement in sputum and the peripheral blood eosinophil count. The total serum IgE level gradually decreased to within the normal range. As a result, the symptoms of exertional dyspnea immediately improved. Improvement in the respiratory function was also recognized.

Figure 6.

Computed tomography images of the chest before (A) and after three cycles of benralizumab (B). Bronchial wall thickening and ground-glass attenuation were significantly improved by benralizumab. The mucus plaque also disappeared.