Department of Respiratory Diseases, Montpellier, France; INSERM U1046, Hôpital Arnaud de Villeneuve, Université Montpellier I et 2, Montpellier, France.
INSERM U1046, Hôpital Arnaud de Villeneuve, Université Montpellier I et 2, Montpellier, France; Service DIM, MISTEA, CHU Montpellier, Montpellier, France.
J Allergy Clin Immunol. 2014 Nov;134(5):1043-50. doi: 10.1016/j.jaci.2014.04.038. Epub 2014 Jun 27.
Cross-sectional severe asthma cluster analysis identified different phenotypes. We tested the hypothesis that these clusters will follow different courses.
We aimed to identify which asthma outcomes are specific and coherently associated with these different phenotypes in a prospective longitudinal cohort.
In a longitudinal cohort of 112 patients with severe asthma, the 5 Severe Asthma Research Program (SARP) clusters were identified by means of algorithm application. Because patients of the present cohort all had severe asthma compared with the SARP cohort, homemade clusters were identified and also tested. At the subsequent visit, we investigated several outcomes related to asthma control at 1 year (6-item Asthma Control Questionnaire [ACQ-6], lung function, and medication requirement) and then recorded the 3-year exacerbations rate and time to first exacerbation.
The SARP algorithm discriminated the 5 clusters at entry for age, asthma duration, lung function, blood eosinophil measurement, ACQ-6 scores, and diabetes comorbidity. Four homemade clusters were mostly segregated by best ever achieved FEV1 values and discriminated the groups by a few clinical characteristics. Nonetheless, all these clusters shared similar asthma outcomes related to asthma control as follows. The ACQ-6 score did not change in any cluster. Exacerbation rate and time to first exacerbation were similar, as were treatment requirements.
Severe asthma phenotypes identified by using a previously reported cluster analysis or newly homemade clusters do not behave differently concerning asthma control-related outcomes, which are used to assess the response to innovative therapies. This study demonstrates a potential limitation of the cluster analysis approach in the field of severe asthma.
横断面严重哮喘聚类分析确定了不同的表型。我们检验了这样一个假设，即这些聚类将遵循不同的病程。
我们旨在确定这些表型在一个前瞻性纵向队列中是否会出现特定的、一致的与不同哮喘结局相关的情况。
在一项前瞻性纵向队列研究中，我们对 112 例严重哮喘患者进行了研究，通过应用算法确定了 5 个严重哮喘研究计划（SARP）聚类。由于本队列的所有患者与 SARP 队列相比都患有严重哮喘，因此确定了自制聚类并进行了测试。在随后的就诊中，我们调查了与哮喘控制相关的 1 年的几种结局（6 项哮喘控制问卷[ACQ-6]、肺功能和药物需求），然后记录了 3 年的加重率和首次加重时间。
SARP 算法在进入队列时根据年龄、哮喘持续时间、肺功能、血嗜酸性粒细胞计数、ACQ-6 评分和糖尿病合并症区分了这 5 个聚类。4 个自制聚类主要通过最佳的 FEV1 值进行区分，并通过少数临床特征对组进行区分。然而，所有这些聚类都表现出类似的与哮喘控制相关的哮喘结局。任何聚类的 ACQ-6 评分都没有变化。加重率和首次加重时间相似，治疗需求也相似。
使用先前报道的聚类分析或新的自制聚类分析确定的严重哮喘表型在与哮喘控制相关的结局方面没有表现出不同，这些结局用于评估对创新疗法的反应。本研究表明聚类分析方法在严重哮喘领域可能存在局限性。
