Bronchoscopy-guided bronchial epithelium sampling as a tool for selecting the optimal biologic treatment in a patient with severe asthma: a case report

Abstract

Background: There are numerous biologics for treating patients with severe asthma. A cost-effective method for selecting the most appropriate biologic therapy for a patient is thus important. Bronchoscopy-guided bronchial epithelium sampling may provide information for determining the type of inflammation in the airways of severe asthma patients through immunochemical analysis and thus help clinicians select the correct biologics.

Case presentation: We report the case of a female with severe asthma and eosinophilia who initially responded to omalizumab treatment. She developed an allergic reaction after four injections of omalizumab. Omalizumab desensitization was successfully conducted. To select an appropriate biologic agent after this hypersensitivity episode, we performed bronchoscopy-guided bronchial epithelium sampling. Omalizumab treatment was resumed based on the findings of immunohistochemical staining after a successful desensitization procedure, leading to long-term control of her severe asthma.

Conclusions: Selecting an adequate biologic agent for severe, uncontrolled asthma is a challenge in clinical medical practice. Although phenotypes, blood eosinophils, and serum IgE levels have been proposed for use as a reference, there is a dissociation between the blood immune-cell level and the airway epithelium immune reaction, as confirmed in previous studies. Airway epithelium immunohistochemistry staining for targeted immune cells has been used to determine various types of airway inflammation; however, this technique is rarely used in a clinical setting. Previous studies have revealed the relative safety of performing bronchoscopy biopsies for patients with severe asthma. Among the sampling techniques used for tissue diagnosis, including nasal biopsies, nasal or bronchial brushing, and bronchoalveolar lavage, bronchoscopy-guided bronchial epithelium sampling provides more accurate information about the epithelial and inflammatory cells in the tissue context. It is thus a powerful tool for selecting the most suitable biologics in difficult clinical conditions.

Keywords: Bronchial epithelium sampling; Omalizumab; Severe asthma.

Conflict of interest statement

Competing interestsThe authors declare that they have no competing interests.

© The Author(s) 2019.

Figures

Fig. 1

PEF level of the patient. The upper and lower bounds of the line represent the range of PEF change during the OPD follow-up period, and the square mark in the middle of the line represents the average maximum and minimum values of PEF during the period. Triangle marks represent the maximum PEF during the period on 2017/03/31, 2018/08/29, 2018/10/24. 2017/05/–2017/08 omalizumab use; 2017/09–2017/10 omalizumab desensitization; 2017/12/18 upper airway infection; 2018/05/07 LLL pneumonia; 2018/07/24 resume omalizumab use. PEF peak expiratory flow

Fig. 2

Immunohistochemistry staining of bronchial epithelium for the patient. a Significant IgE-positive epithelium cells in the specimen, indicating a strong IgE-mediate immune reaction in the patient’s airway. b Weak positive staining of IL-5 in the submucosal area