Southwest Asthma and Allergy Associates, Houston, TX, USA.
University of South Florida, Tampa, FL, USA.
Clin Exp Allergy. 2021 Apr;51(4):546-555. doi: 10.1111/cea.13790. Epub 2021 Jan 7.
Current biologic therapies target allergic, eosinophilic or type 2 inflammation phenotypic asthma. However, frequency and degree of overlap among these subtypes is unclear.
To characterize overlap among allergic, eosinophilic and type 2 asthma phenotypes.
Post hoc analyses of baseline data were performed in two adult populations: (a) not selected for any asthma subtype (N = 935) and (b) selected for allergic asthma (N = 1049). Degree of overlap was examined using commonly accepted phenotypic definitions to guide treatment for allergic asthma (skin prick-positive and/or positive serum-specific immunoglobulin E > 0.35 kU/L) and eosinophilic asthma (blood eosinophil high count ≥ 300 cells/µL; low cut-off ≥ 150 cells/µL). Consistent with previous studies, fractional exhaled nitric oxide high level of ≥ 35 ppb and low cut-off of ≥ 25 ppb were selected as local markers of type 2 inflammation and to prevent overlap with the systemic eosinophilic asthma definition.
In the non-subtype-selected population, 78.0% had allergic asthma; of these, 39.5% had eosinophilic asthma and 29.5% had type 2 asthma. Within patients with eosinophilic asthma (40.6% of total), 75.8% had allergic asthma and 41.3% had type 2 asthma. Within patients with type 2 asthma (28.3% of total), 81.1% had allergic asthma and 59.2% had eosinophilic asthma. In the allergic asthma-selected population, 38.3% had eosinophilic asthma and 29.2% had type 2 asthma. Within patients with eosinophilic asthma, 46.3% had type 2 asthma. Within patients with type 2 asthma, 60.8% had eosinophilic asthma. Overlaps among subtypes increased at low cut-off values.
In this post hoc analysis in adults with moderate-to-severe asthma, allergic asthma was the most prevalent phenotype, followed by eosinophilic and type 2 asthma. Despite observed overlaps, a considerable proportion of patients had only a predominantly allergic subtype. Understanding the degree of overlap across phenotypes will help patient management and guide treatment options.
目前的生物疗法针对过敏性、嗜酸性粒细胞或 2 型炎症表型哮喘。然而，这些亚型之间的频率和程度尚不清楚。
描述过敏性、嗜酸性粒细胞和 2 型哮喘表型之间的重叠。
对两个成人人群的基线数据进行了事后分析：（a）未选择任何哮喘亚型（N=935）和（b）选择过敏性哮喘（N=1049）。使用常用于指导过敏性哮喘治疗的表型定义（皮肤点刺阳性和/或血清特异性免疫球蛋白 E 阳性>0.35 kU/L）和嗜酸性粒细胞性哮喘（血嗜酸粒细胞高计数≥300 细胞/µL；低截止值≥150 细胞/µL）来检查重叠程度。与先前的研究一致，选择呼出的一氧化氮分数高水平≥35 ppb 和低截止值≥25 ppb 作为 2 型炎症的局部标志物，并防止与系统性嗜酸性粒细胞性哮喘定义重叠。
在未选择亚型的人群中，78.0%有过敏性哮喘；其中，39.5%有嗜酸性粒细胞性哮喘，29.5%有 2 型哮喘。在嗜酸性粒细胞性哮喘患者中（占总人数的 40.6%），75.8%有过敏性哮喘，41.3%有 2 型哮喘。在 2 型哮喘患者中（占总人数的 28.3%），81.1%有过敏性哮喘，59.2%有嗜酸性粒细胞性哮喘。在过敏性哮喘患者中，38.3%有嗜酸性粒细胞性哮喘，29.2%有 2 型哮喘。在嗜酸性粒细胞性哮喘患者中，46.3%有 2 型哮喘。在 2 型哮喘患者中，60.8%有嗜酸性粒细胞性哮喘。在低截止值时，各亚型之间的重叠增加。
在这项对中重度哮喘成人的事后分析中，过敏性哮喘是最常见的表型，其次是嗜酸性粒细胞性和 2 型哮喘。尽管存在重叠，但相当一部分患者仅具有主要的过敏性亚型。了解各表型之间的重叠程度将有助于患者管理和指导治疗选择。
