Landis Sarah, Suruki Robert, Maskell Joe, Bonar Kerina, Hilton Emma, Compton Chris
a Real World Evidence & Epidemiology, GSK , Uxbridge , UK.
b Real World Evidence & Epidemiology, GSK , Research Triangle Park, North Carolina , USA.
COPD. 2018 Apr;15(2):177-184. doi: 10.1080/15412555.2018.1441275. Epub 2018 Mar 20.
Blood eosinophil count may be a useful biomarker for predicting response to inhaled corticosteroids and exacerbation risk in chronic obstructive pulmonary disease (COPD) patients. The optimal cut point for categorizing blood eosinophil counts in these contexts remains unclear. We aimed to determine the distribution of blood eosinophil count in COPD patients and matched non-COPD controls, and to describe demographic and clinical characteristics at different cut points. We identified COPD patients within the UK Clinical Practice Research Database aged ≥40 years with a FEV/FVC <0.7, and ≥1 blood eosinophil count recorded during stable disease between January 1, 2010 and December 31, 2012. COPD patients were matched on age, sex, and smoking status to non-COPD controls. Using all blood eosinophil counts recorded during a 12-month period, COPD patients were categorized as "always above," "fluctuating above and below," and "never above" cut points of 100, 150, and 300 cells/μL. The geometric mean blood eosinophil count was statistically significantly higher in COPD patients versus matched controls (196.6 cells/µL vs. 182.1 cells/µL; mean difference 8%, 95% CI: 6.8, 9.2), and in COPD patients with versus without a history of asthma (205.0 cells/µL vs. 192.2 cells/µL; mean difference 6.7%, 95%, CI: 4.9, 8.5). About half of COPD patients had all blood eosinophil counts above 150 cells/μL; this persistent higher eosinophil phenotype was associated with being male, higher body mass index, and history of asthma. In conclusion, COPD patients demonstrated higher blood eosinophil count than non-COPD controls, although there was substantial overlap in the distributions. COPD patients with a history of asthma had significantly higher blood eosinophil count versus those without.
血液嗜酸性粒细胞计数可能是预测慢性阻塞性肺疾病（COPD）患者对吸入性糖皮质激素反应及急性加重风险的有用生物标志物。在这些情况下，用于对血液嗜酸性粒细胞计数进行分类的最佳切点仍不明确。我们旨在确定COPD患者和匹配的非COPD对照者的血液嗜酸性粒细胞计数分布，并描述不同切点时的人口统计学和临床特征。我们在英国临床实践研究数据库中确定了年龄≥40岁、FEV/FVC<0.7且在2010年1月1日至2012年12月31日稳定期疾病期间记录有≥1次血液嗜酸性粒细胞计数的COPD患者。COPD患者在年龄、性别和吸烟状况方面与非COPD对照者相匹配。使用在12个月期间记录的所有血液嗜酸性粒细胞计数，将COPD患者分为“始终高于”、“上下波动”和“从未高于”100、150和300个细胞/μL的切点。COPD患者的几何平均血液嗜酸性粒细胞计数在统计学上显著高于匹配的对照者（196.6个细胞/µL对182.1个细胞/µL；平均差异8%，95%CI：6.8，9.2），并且有哮喘病史的COPD患者与无哮喘病史的患者相比（205.0个细胞/µL对192.2个细胞/µL；平均差异6.7%，95%CI：4.9，8.5）。约一半的COPD患者所有血液嗜酸性粒细胞计数高于150个细胞/μL；这种持续较高的嗜酸性粒细胞表型与男性、较高的体重指数和哮喘病史有关。总之，COPD患者的血液嗜酸性粒细胞计数高于非COPD对照者，尽管分布存在大量重叠。有哮喘病史的COPD患者的血液嗜酸性粒细胞计数显著高于无哮喘病史的患者。
