- Title
- Peripheral blood eosinophils: a surrogate marker for airway eosinophilia in stable COPD
- Creator
- Negewo, Netsanet A.; McDonald, Vanessa M.; Baines, Katherine J.; Wark, Peter A. B.; Simpson, Jodie L.; Jones, Paul W.; Gibson, Peter G.
- Relation
- NHMRC.1045230 and NHMRC 455508 http://purl.org/au-research/grants/nhmrc/455508
- Relation
- The International Journal of Chronic Obstructive Pulmonary Disease Vol. 11, Issue 1, p. 1495-1504
- Publisher Link
- http://dx.doi.org/10.2147/COPD.S100338
- Publisher
- Dove Medical Press
- Resource Type
- journal article
- Date
- 2016
- Description
- Introduction: Sputum eosinophilia occurs in approximately one-third of stable chronic obstructive pulmonary disease (COPD) patients and can predict exacerbation risk and response to corticosteroid treatments. Sputum induction, however, requires expertise, may not always be successful, and does not provide point-of-care results. Easily applicable diagnostic markers that can predict sputum eosinophilia in stable COPD patients have the potential to progress COPD management. This study investigated the correlation and predictive relationship between peripheral blood and sputum eosinophils. It also examined the repeatability of blood eosinophil counts. Methods: Stable COPD patients (n=141) were classified as eosinophilic or noneosinophilic based on their sputum cell counts (≥3%), and a cross-sectional analysis was conducted comparing their demographics, clinical characteristics, and blood cell counts. Receiver operating characteristic curve analysis was used to assess the predictive ability of blood eosinophils for sputum eosinophilia. Intraclass correlation coefficient was used to examine the repeatability of blood eosinophil counts. Results: Blood eosinophil counts were significantly higher in patients with sputum eosinophilia (n=45) compared to those without (0.3×109/L vs 0.15×109/L; P<0.0001). Blood eosinophils correlated with both the percentage (ρ=0.535; P<0.0001) and number of sputum eosinophils (ρ=0.473; P<0.0001). Absolute blood eosinophil count was predictive of sputum eosinophilia (area under the curve =0.76, 95% confidence interval [CI] =0.67–0.84; P<0.0001). At a threshold of ≥0.3×10
/L (specificity =76%, sensitivity =60%, and positive likelihood ratio =2.5), peripheral blood eosinophil counts enabled identification of the presence or absence of sputum eosinophilia in 71% of the cases. A threshold of ≥0.4×109/L had similar classifying ability but better specificity (91.7%) and higher positive likelihood ratio (3.7). In contrast, ≥0.2×109/L offered a better sensitivity (91.1%) for ruling out sputum eosinophilia. There was a good agreement between two measurements of blood eosinophil count over a median of 28 days (intraclass correlation coefficient =0.8; 95% CI =0.66–0.88; P<0.0001). Conclusion: Peripheral blood eosinophil counts can help identify the presence or absence of sputum eosinophilia in stable COPD patients with a reasonable degree of accuracy. - Subject
- sputum eosinophilia; diagnostic accuracy; chronic obstructive pulmonary disease; stability of eosinophil counts
- Identifier
- http://hdl.handle.net/1959.13/1345921
- Identifier
- uon:29745
- Identifier
- ISSN:1176-9106
- Rights
- This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.
- Language
- eng
- Full Text
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