TY - JOUR
T1 - Case Report
T2 - Eosinophilic Bronchiolitis With Eosinophil ETosis in Mucus Plugs Successfully Treated With Benralizumab
AU - Sasaki, Hisashi
AU - Miyata, Jun
AU - Irie, Akiko
AU - Kuwata, Ayako
AU - Kouzaki, Yuji
AU - Ueki, Shigeharu
AU - Kawana, Akihiko
N1 - Funding Information:
We thank Yuji Fujikura and Yoshifumi Kimizuka (National Defense Medical College) for clinical assistance.
Publisher Copyright:
Copyright © 2022 Sasaki, Miyata, Irie, Kuwata, Kouzaki, Ueki and Kawana.
PY - 2022/1/13
Y1 - 2022/1/13
N2 - Eosinophilic bronchiolitis is a rare allergic disorder caused by eosinophilic inflammation in the bronchioles of the lungs. An effective treatment strategy is needed in cases resistant to steroids. However, its pathophysiology remains unclear owing to the limited number of cases. We herein present the case of a 31-year-old man who experienced eosinophilic bronchiolitis with eosinophil ETosis (EETosis) in the mucus plugs. The patient was diagnosed with asthma. His respiratory symptoms worsened with eosinophilia when treated with the standard asthma regimen, including inhaled corticosteroids, long-acting β2-agonist, long-acting muscarinic antagonist, and leukotriene receptor antagonist. Chest computed tomography revealed bronchial wall thickening and centrilobular nodules in the lower lobes of both lungs. Bronchoscopy showed obstruction of the subsegmental bronchus with mucus plugs. Histological analysis demonstrated abundant eosinophils in the mucus plugs. Cytolytic eosinophils together with Charcot–Leyden crystal formations and deposition of major basic proteins were also observed, indicating the occurrence of EETosis. Introduction of benralizumab, an anti-interleukin-5 receptor α antibody, successfully controlled the patient’s condition and reduced the amount of systemic corticosteroids administered. Our findings confirm that this antibody strongly decreases airway eosinophils in patients with severe asthma. Thus, benralizumab might be an optimal therapeutic agent for the treatment of mucus plug-forming and/or EETosis-occurring eosinophilic lung diseases, including eosinophilic bronchiolitis.
AB - Eosinophilic bronchiolitis is a rare allergic disorder caused by eosinophilic inflammation in the bronchioles of the lungs. An effective treatment strategy is needed in cases resistant to steroids. However, its pathophysiology remains unclear owing to the limited number of cases. We herein present the case of a 31-year-old man who experienced eosinophilic bronchiolitis with eosinophil ETosis (EETosis) in the mucus plugs. The patient was diagnosed with asthma. His respiratory symptoms worsened with eosinophilia when treated with the standard asthma regimen, including inhaled corticosteroids, long-acting β2-agonist, long-acting muscarinic antagonist, and leukotriene receptor antagonist. Chest computed tomography revealed bronchial wall thickening and centrilobular nodules in the lower lobes of both lungs. Bronchoscopy showed obstruction of the subsegmental bronchus with mucus plugs. Histological analysis demonstrated abundant eosinophils in the mucus plugs. Cytolytic eosinophils together with Charcot–Leyden crystal formations and deposition of major basic proteins were also observed, indicating the occurrence of EETosis. Introduction of benralizumab, an anti-interleukin-5 receptor α antibody, successfully controlled the patient’s condition and reduced the amount of systemic corticosteroids administered. Our findings confirm that this antibody strongly decreases airway eosinophils in patients with severe asthma. Thus, benralizumab might be an optimal therapeutic agent for the treatment of mucus plug-forming and/or EETosis-occurring eosinophilic lung diseases, including eosinophilic bronchiolitis.
KW - Charcot-Leyden crystal
KW - ETosis
KW - benralizumab
KW - eosinophil
KW - eosinophilic bronchiolitis
KW - mucus plug
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U2 - 10.3389/fphar.2021.826790
DO - 10.3389/fphar.2021.826790
M3 - Article
AN - SCOPUS:85123802853
SN - 1663-9812
VL - 12
JO - Frontiers in Pharmacology
JF - Frontiers in Pharmacology
M1 - 826790
ER -