Rapidly progressive mucus plugs in allergic bronchopulmonary mycosis

Abstract

Introduction

Allergic bronchopulmonary mycosis (ABPM) is a chronic airway disease characterized by the presence of fungi that trigger allergic reactions and airway obstruction. Here, we present a unique case of ABPM in which a patient experienced sudden respiratory failure due to mucus plug-induced airway obstruction. The patient’s life was saved by venovenous extracorporeal membrane oxygenation (VV-ECMO) and bronchoscopic removal of the plug. This case emphasizes the clinical significance of mucus plug-induced airway obstruction in the differential diagnosis of respiratory failure in patients with ABPM.

Case study

A 52-year-old female clerical worker with no smoking history, presented with dyspnea. CT scan revealed mucus plugs in both lungs. Despite treatment, the dyspnea progressed rapidly to respiratory failure, leading to VV-ECMO placement.

Results

CT revealed bronchial wall thickening, obstruction, and extensive atelectasis. Bronchoscopy revealed extensive mucus plugs that were successfully removed within two days. The patient’s respiratory status significantly improved. Follow-up CT revealed no recurrence. Fungal cultures identified Schizophyllum commune, confirming ABPM. Histological examination of the mucus plugs revealed aggregated eosinophils, eosinophil granules, and Charcot-Leyden crystals. Galectin-10 and major basic protein (MBP) staining supported these findings. Eosinophil extracellular traps (EETs) and eosinophil cell death (ETosis), which contribute to mucus plug formation, were identified by citrullinated histone H3 staining.

Conclusion

Differentiating between asthma exacerbation and mucus plug-induced airway obstruction in patients with ABPM and those with acute respiratory failure is challenging. Prompt evaluation of mucous plugs and atelectasis using CT and timely decision to introduce ECMO and bronchoscopic mucous plug removal are required.

Keywords:

• Bronchoscopy
• eosinophil extracellular traps
• mucous plug
• veno-venous extracorporeal membrane oxygenation
• Schizophyllum commune

Acknowledgments

We thank Dr. Katsuhiko Kamei of the Department of Infectious Diseases, Ishinomaki Red Cross Hospital, Japan. and we also thank the Medical Mycology Research Center, Chiba University, preserving the causative agent as IFM 67871 through the National Bio-Resource Project, Japan. We would like to thank Editage (www.editage.jp) for English language editing.

Disclosure statement

AI received honoraria for lecture from AstraZeneca (AZ).

KS　received honoraria for lecture from Sanofi.

SI received honoraria for lectures from AstraZeneca (AZ), GSK, KYORIN Pharmaceutical Co.,Ltd., Novartis, and Sanofi and grant support from KYORIN Pharmaceutical Co.,Ltd. SU received honoraria for lectures from AstraZeneca (AZ) and GSK and grant support from AZ, Novartis, and Maruho Co., Ltd.

SU received honoraria for lectures from AstraZeneca (AZ) and GSK and grant support from AZ, Novartis, and Maruho Co., Ltd. The authors declare no competing financial interests.

Additional information

Funding

This study was funded in part by research grants on allergic diseases and immunology from the Japan Agency for Medical Research and Development (JP22ek0410097), JSPS KAKENHI (20K08794, 21K08434, 20H03832, and 21K07833), and MHLW 202213003A (to SU).