A case of allergic bronchopulmonary aspergillosis with marked peripheral blood eosinophilia successfully treated with benralizumab

Abstract

We herein report a case of allergic bronchopulmonary aspergillosis (ABPA) with marked eosinophilia and high attenuation mucus (HAM) on chest computed tomography (CT), which demonstrated a rapid and remarkable improvement with benralizumab treatment. A 67-year-old Japanese woman, who was diagnosed with asthma at the age of 64 years, was admitted with dyspnea. Her blood test results showed marked eosinophilia (peripheral blood eosinophil count 24403/μL) and elevated serum IgE levels. Chest CT also revealed ground-glass opacity. Sputum cytology detected filamentous fungi, suggesting an infection with Aspergillus spp. Based on these findings, ABPA was diagnosed. Following systemic corticosteroid treatment, her respiratory symptoms and chest radiography findings showed improvements. However, with the gradual tapering and eventual discontinuance of the corticosteroid therapy, a concomitant increase in the peripheral blood eosinophils and a recurrence of the clinical symptoms, was observed. In addition, her pulmonary function decreased and chest CT revealed worsened bronchial mucus plugs. To control the asthma with ABPA exacerbation, benralizumab was administered. Following treatment with benralizumab, the patient's asthmatic symptoms improved, together with a decrease in her peripheral eosinophil count. Mucus plugs were no longer visible on chest CT. Pulmonary function test result also showed a remarkable improvement. There was no relapse of dyspnea and no reappearance of the mucus plugs. This case suggests that benralizumab may be a suitable treatment option for patients with ABPA with marked eosinophilia and HAM on chest CT.

Keywords: Allergic bronchopulmonary aspergillosis; Benralizumab; Eosinophilia; High-attenuation mucus.

Fig. 1

Chest imaging appearance and sputum cytology at the time of diagnosis. (A) Chest radiography on admission showing ground-glass attenuation in bilateral lung fields. (B) Chest CT revealing ground-glass attenuation in bilateral upper lobe areas and central bronchiectasis with high-attenuation mucus (HAM) (allow) in the left lung. (C) Sputum cytology showing some filamentous fungi, which were suspected to be Aspergillus spp. (Papanicolaou staining × 200).

Fig. 2

Chest imaging appearance before and after treatment with benralizumab. (A) Chest radiography before treatment with benralizumab showing ground-glass attenuation in the left lower lung field. (B) Chest CT before treatment with benralizumab showing high-attenuation mucus plugs in bilateral lungs (allow) and atelectasis in the lingular segment of the left lung. (C) Chest radiography 3 months after treatment with benralizumab, showing improvement in ground-glass attenuation in the left lower lung field. (D) Chest CT 3 months after treatment with benralizumab, showing high attenuation mucus plugs and atelectasis.