1. Blood eosinophil count correlates with alveolar damage in emphysema-predominant COPD
- Author
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Saya Nakamura, Keiko Wakahara, Suguru Majima, Eito Yokoi, Eriko Fukutani, Ryo Otsuki, Shingo Iwano, Toyofumi Fengshi Chen-Yoshikawa, Fumie Kinoshita, Takashi Abe, Toyokazu Sashio, Tomoki Kimura, Kenji Izuhara, Naozumi Hashimoto, Makoto Ishii, and Yoshinori Hasegawa
- Subjects
COPD ,Blood eosinophil count ,Emphysema-predominant COPD ,Asthma-COPD overlap ,Periostin ,Type-2 biomarker ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Although blood eosinophil count is recognized as a useful biomarker for the management of chronic obstructive pulmonary disease (COPD), the impact of eosinophils in COPD has not been fully elucidated. Here we aimed to investigate the relationships between the blood eosinophil count and various clinical parameters including lung structural changes. Methods Ninety-three COPD patients without concomitant asthma were prospectively enrolled in this study. Blood eosinophil count, serum IgE level, serum periostin level, and chest computed tomography (CT) scans were evaluated. Eosinophilic COPD was defined as COPD with a blood eosinophil count ≧ 300/µL. We examined the correlation between the blood eosinophil count and structural changes graded by chest CT, focusing specifically on thin airway wall (WT thin) and thick airway wall (WT thick) groups. In a separate cohort, the number of eosinophils in the peripheral lungs of COPD patients with low attenuation area (LAA) on chest CT was assessed using lung resection specimens. Results The mean blood eosinophil count was 212.1/µL, and 18 patients (19.3%) were categorized as having eosinophilic COPD. In the whole group analysis, the blood eosinophil count correlated only with blood white blood cells, blood basophils, C-reactive protein level, and sputum eosinophils. However, the blood eosinophil count positively correlated with the percentage of LAA and negatively correlated with the diffusing capacity for carbon monoxide in the WT thin group. Lung specimen data showed an increased number of eosinophils in the peripheral lungs of COPD patients with LAA on chest CT scans compared to normal controls. Conclusions Some COPD patients without concomitant asthma showed a phenotype of high blood eosinophils. Alveolar damage may be related to eosinophilic inflammation in patients with COPD without asthma and thickening of the central airway wall.
- Published
- 2024
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