Division of Respiratory and Critical Care Medicine, Department of Medicine, National University Hospital, National University Health System, Singapore.
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Korean J Intern Med. 2021 Nov;36(6):1305-1319. doi: 10.3904/kjim.2021.180. Epub 2021 Oct 12.
Approximately 25% to 40% of patients with chronic obstructive pulmonary disease (COPD) have the eosinophilic endotype. It is important to identify this group accurately because they are more symptomatic and are at increased risk for exacerbations and accelerated decline in forced expiratory volume in the 1st second. Importantly, this endotype is a marker of treat ment responsiveness to inhaled corticosteroid (ICS), resulting in decreased mortality risk. In this review, we highlight differences in the biology of eosinophils in COPD compared to asthma and the different definitions of the COPD eosinophilic endotype based on sputum and blood eosinophil count (BEC) with the corresponding limitations. Although BEC is useful as a biomarker for eosinophilic COPD endotype, optimal BEC cut-offs can be combined with clinical characteristics to improve its sensitivity and specificity. A targeted approach comprising airway eosinophilia and appropriate clinical and physiological features may improve identification of subgroups of patients who would benefit from biologic therapy or early use of ICS for disease modification.
约 25%至 40%的慢性阻塞性肺疾病（COPD）患者存在嗜酸性粒细胞表型。准确识别这组患者非常重要，因为他们的症状更明显，并且更容易发生恶化和第 1 秒用力呼气量（FEV1）加速下降的风险增加。重要的是，这种表型是对吸入性皮质类固醇（ICS）治疗反应的标志物，从而降低了死亡风险。在这篇综述中，我们强调了 COPD 中嗜酸性粒细胞的生物学特性与哮喘的不同之处，以及基于痰和血液嗜酸性粒细胞计数（BEC）的 COPD 嗜酸性粒细胞表型的不同定义及其相应的局限性。尽管 BEC 可作为嗜酸性粒细胞表型的 COPD 的生物标志物，但最佳的 BEC 截断值可以与临床特征相结合，以提高其敏感性和特异性。包括气道嗜酸性粒细胞和适当的临床和生理特征的靶向方法可能会提高识别那些受益于生物治疗或早期使用 ICS 进行疾病修饰的亚组患者的能力。
