Institute of Respiratory Diseases, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing 400037, China.
Biomed Res Int. 2018 Jul 9;2018:9230234. doi: 10.1155/2018/9230234. eCollection 2018.
Neutrophilic asthma (NA) is an important asthma inflammatory phenotype associated with disease severity, airflow limitation, and steroid resistance, and its mechanism is still uncertain. Evidences suggest a potential role for bacteria in its pathogenesis, but, so far, this remains poorly understood. We sought to investigate airway bacterial burden, community composition, and inflammatory response in NA. Fifty-four stable asthmatics without infection were enrolled and separated into either NA group (n = 20) or non-NA group (n = 34). Subject demographics, Asthma Control Test (ACT) scores, medications, and pulmonary functions were documented. Sputum cytology, airway bacterial burden, microbial community composition, and inflammatory cytokines were assessed. The total airway bacterial burden was significantly increased in subjects with NA versus non-NA and was positively correlated with the sputum neutrophil percentage. Airway neutrophilia was associated with less airway bacterial community richness and diversity, along with a distinct community composition. In patients with NA, bacteria in phylum Proteobacteria, especially spp. and spp., showed significant increases in both actual loads and relative abundances, while bacteria in phyla Firmicutes, Actinobacteria, and Saccharibacteria showed decreased relative abundances compared with non-NA. Patients with NA demonstrated higher levels of interleukin-1 (IL-1), IL-6, IL-8, IL-12, IL-17A, and tumor necrosis factor- (TNF-) in sputum samples compared with non-NA. Increased bacterial burden and distinct microbiota composition were the key characters of neutrophilic phenotype in asthma, accompanied by excessive airway inflammation. Understanding the relationship between airway microbiota and neutrophilic inflammation may help in treatment and management of asthma, such as targeting airway microbiota.
中性粒细胞性哮喘（NA）是一种与疾病严重程度、气流受限和激素抵抗相关的重要哮喘炎症表型，其机制尚不清楚。有证据表明细菌在其发病机制中可能起作用，但到目前为止，这方面的了解仍很有限。我们试图研究 NA 患者的气道细菌负担、群落组成和炎症反应。纳入 54 例稳定期无感染的哮喘患者，分为 NA 组（n = 20）和非 NA 组（n = 34）。记录患者的人口统计学特征、哮喘控制测试（ACT）评分、药物使用情况和肺功能。评估痰细胞学、气道细菌负担、微生物群落组成和炎症细胞因子。与非 NA 患者相比，NA 患者的总气道细菌负担显著增加，且与痰中性粒细胞百分比呈正相关。气道中性粒细胞增多与气道细菌群落丰富度和多样性降低以及独特的群落组成相关。在 NA 患者中，厚壁菌门（Firmicutes）、放线菌门（Actinobacteria）和酸杆菌门（Saccharibacteria）的细菌相对丰度降低，而变形菌门（Proteobacteria）的细菌，尤其是 和 ，其实际负荷和相对丰度均显著增加。与非 NA 患者相比，NA 患者的痰样中白细胞介素-1（IL-1）、IL-6、IL-8、IL-12、IL-17A 和肿瘤坏死因子-α（TNF-α）水平更高。气道细菌负担增加和独特的微生物群落组成是哮喘中性粒细胞表型的关键特征，同时伴有过度的气道炎症。了解气道微生物群与中性粒细胞炎症之间的关系可能有助于哮喘的治疗和管理，例如靶向气道微生物群。
