Background: Despite most of the asthma population having mild disease, the mild asthma phenotype is poorly understood. Here, we aim to address this gap in knowledge by extensively characterising the mild asthma phenotype and comparing this with difficult-to-treat asthma.
Methods: We assessed two real-world adult cohorts from the South of England using an identical methodology: the Wessex AsThma CoHort of difficult asthma (WATCH) (n=498) and a mild asthma cohort from the comparator arm of the Epigenetics Of Severe Asthma (EOSA) study (n=67). Data acquisition included detailed clinical, health and disease-related questionnaires, anthropometry, allergy and lung function testing, plus biological samples (blood and sputum) in a subset.
Results: Mild asthma is predominantly early-onset and is associated with type-2 (T2) inflammation (atopy, raised fractional exhaled nitric oxide (FeNO), blood/sputum eosinophilia) plus preserved lung function. A high prevalence of comorbidities and multimorbidity was observed in mild asthma, particularly depression (58.2%) and anxiety (56.7%). In comparison to difficult asthma, mild disease showed similar female predominance (> 60%), T2-high inflammation and atopy prevalence, but lower peripheral blood/airway neutrophil counts and preserved lung function. Mild asthma was also associated with a greater prevalence of current smokers (20.9%). A multi-component T2-high inflammatory measure was comparable between the cohorts; T2-high status 88.1% in mild asthma and 93.5% in difficult asthma.
Conclusion: Phenotypic characterisation of mild asthma identified early-onset disease with high prevalence of current smokers, T2-high inflammation and significant multimorbidity burden. Early comprehensive assessment of mild asthma patients could help prevent potential later progression to more complex severe disease.



中文翻译：

---

轻度哮喘与难治性哮喘在表型上有何不同？

背景： 尽管大多数哮喘人群患有轻度疾病，但人们对轻度哮喘表型知之甚少。在这里，我们的目标是通过广泛描述轻度哮喘表型并将其与难治性哮喘进行比较来弥补这一知识差距。
方法：我们评估了来自英格兰南部的两个现实世界成人队列使用相同的方法：困难哮喘 (WATCH) 的威塞克斯哮喘队列 (n=498) 和来自严重哮喘表观遗传学 (EOSA) 研究的比较组的轻度哮喘队列（n=67）。数据采集​​包括详细的临床、健康和疾病相关问卷、人体测量、过敏和肺功能测试，以及子集中的生物样本（血液和痰）。
结果： 轻度哮喘主要为早发性哮喘，与 2 型 (T2) 炎症（特应性、呼出一氧化氮 (FeNO) 分数升高、血液/痰液嗜酸性粒细胞增多）以及保留的肺功能有关。在轻度哮喘中观察到合并症和多重发病率较高，特别是抑郁症（58.2%）和焦虑症（56.7%）。与难治性哮喘相比，轻度疾病表现出相似的女性优势（>60%）、T2高炎症和特应性患病率，但外周血/气道中性粒细胞计数较低且肺功能保留。轻度哮喘也与当前吸烟者的患病率较高有关（20.9%）。队列之间的多成分 T2 高炎症测量结果具有可比性；轻度哮喘中 T2 高状态为 88.1%，困难哮喘中为 93.5%。
结论：轻度哮喘的表型特征表明早发型疾病的患病率很高。当前吸烟者、T2-高炎症和显着的多重疾病负担。对轻度哮喘患者进行早期综合评估有助于防止后期可能发展为更复杂的严重疾病。