Dept of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Copenhagen, Denmark.
The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Copenhagen, Denmark.
Eur Respir J. 2018 May 24;51(5). doi: 10.1183/13993003.00120-2018. Print 2018 May.
Blood eosinophil count in chronic obstructive pulmonary disease (COPD) is associated with higher exacerbation rate and favourable response to corticosteroids; however, frequent exacerbations and use of inhaled corticosteroids could elevate pneumonia risk. We tested the hypothesis that high blood eosinophil counts are associated with high risk of pneumonia in individuals with severe COPD from the general population.We included 7180 individuals with COPD from the Copenhagen General Population Study, including 643 with forced expiratory volume in 1 s (FEV) <50% predicted between 2003 and 2011. All primary discharge diagnoses of pneumonia during follow-up were recorded.Among individuals with COPD and FEV <50% pred, the multivariable adjusted incidence rate ratio was 2.17 (95% CI 1.31-3.58) for pneumonia comparing individuals with blood eosinophil counts ≥0.34×10 cells·L <0.34×10 cells·L In individuals with clinical COPD, defined by recent exacerbation, ≥10 pack-years of smoking and FEV <70% pred, the corresponding risk was 4.52 (2.11-9.72). Risk of pneumonia did not differ by blood eosinophil count in individuals with COPD and FEV ≥50% pred.In individuals with COPD and FEV <50% pred, blood eosinophil count ≥0.34×10 cells·L was associated with high risk of hospitalisation due to pneumonia.
血液嗜酸性粒细胞计数与慢性阻塞性肺疾病（COPD）的更高恶化率和对皮质类固醇的有利反应相关；然而，频繁恶化和使用吸入皮质类固醇可能会增加肺炎的风险。我们检验了这样一个假设，即高血液嗜酸性粒细胞计数与一般人群中重度 COPD 患者的高肺炎风险相关。
我们纳入了来自哥本哈根普通人群研究的 7180 名 COPD 患者，其中包括 2003 年至 2011 年期间有 643 名用力呼气量（FEV）<50%预测值的患者。在随访期间，所有肺炎的主要出院诊断均被记录下来。
在 FEV <50% pred 的 COPD 患者中，与血液嗜酸性粒细胞计数≥0.34×10⁹细胞·L⁻¹相比，血液嗜酸性粒细胞计数≥0.34×10⁹细胞·L⁻¹的患者肺炎的多变量校正发病率比为 2.17（95%CI 1.31-3.58）。在由近期恶化、≥10 包年吸烟史和 FEV <70% pred 定义的有临床 COPD 的患者中，相应的风险为 4.52（2.11-9.72）。在 FEV ≥50% pred 的 COPD 患者中，肺炎的风险并未因血液嗜酸性粒细胞计数而有所不同。
在 FEV <50% pred 的 COPD 患者中，血液嗜酸性粒细胞计数≥0.34×10⁹细胞·L⁻¹与因肺炎住院的高风险相关。
