Spector Sheldon Laurence, Tan Ricardo Antonio
Department of Medicine, UCLA Medical Center, Los Angeles, CA 90095, USA.
J Asthma. 2012 Oct;49(8):807-10. doi: 10.3109/02770903.2012.713428. Epub 2012 Aug 20.
"Eosinophilic asthma" refers to an asthma phenotype characterized by predominance of eosinophils in the bronchial airways and corticosteroid responsiveness. Recent clinical trials of eosinophil-blocking agents have utilized a blood eosinophil count of 300 or 400 eosinophils/mm(3) or higher to identify subjects with moderate to severe asthma. We observed multiple instances of counts which varied widely in the same patient within the same day.
To determine whether there is significant variability in blood eosinophil counts taken throughout the day in the same patients with moderate asthma.
Twelve subjects had serial blood eosinophil counts obtained within a 24-hour period.
Twelve subjects were enrolled: seven subjects had moderate asthma, three subjects had mild asthma, and two control subjects had no asthma. The variability of blood eosinophil counts ranged from 17% to 396%. No specific diurnal pattern was found among the subjects. The highest variability were seen in three moderate asthmatics (396%, 170%, and 154%) and one mild asthmatic (164%) while the other subjects had variability of 84% or less.
This study showed significant variability in blood eosinophil counts within a 24-hour period in the same subjects. The highest variability was seen in moderate asthmatics. These findings would appear to place the utility of a single eosinophil count in question.
“嗜酸性粒细胞性哮喘”是指一种哮喘表型，其特征为支气管气道中嗜酸性粒细胞占优势且对皮质类固醇有反应。嗜酸性粒细胞阻滞剂的近期临床试验利用血液嗜酸性粒细胞计数300或400个嗜酸性粒细胞/mm³或更高来识别中度至重度哮喘患者。我们观察到同一患者在同一天内计数多次出现大幅波动的情况。
确定中度哮喘患者同一天内全天的血液嗜酸性粒细胞计数是否存在显著变异性。
12名受试者在24小时内进行了系列血液嗜酸性粒细胞计数。
共纳入12名受试者：7名中度哮喘患者，3名轻度哮喘患者，2名对照受试者无哮喘。血液嗜酸性粒细胞计数的变异性范围为17%至396%。受试者中未发现特定的昼夜模式。变异性最高的是3名中度哮喘患者（396%、170%和154%）和1名轻度哮喘患者（164%），而其他受试者的变异性为84%或更低。
本研究表明同一受试者在24小时内血液嗜酸性粒细胞计数存在显著变异性。变异性最高的是中度哮喘患者。这些发现似乎使单次嗜酸性粒细胞计数的实用性受到质疑。
