A Low Eosinophil to Platelet Ratio as a Worse Prognostic Index for Emergency Department Attendance in Acute Exacerbation of COPD

Abstract

Purpose

Identifying prognosis for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is challenging. Eosinophils and platelet are involved in the development of COPD, which may predict adverse events. The objective of this study was to determine the effect of the eosinophil to platelet ratio (EPR) in predicting adverse events in patients with AECOPD who visited the emergency department.

Patients and Methods

The records of patients with AECOPD treated at Dalian Municipal Friendship Hospital from January 2018 to December 2020 were retrospectively reviewed. The relationship between the clinical characteristics and EPR, as cut-off value of 0.755, was evaluated.

Results

A total of 508 patients with an AECOPD (316 male, 192 female) were included. An optimal AUC cutoff of 0.755 for the EPR segregated the patients into 2 groups with significantly different mortality (25.3% vs 5.5%, P < 0.001). The same mortality risk with lower EPR was observed among the patients with emergency room attendance (35.6% vs 11.1%, P < 0.001). A model including EPR <0.755, exacerbation history, PaO2 <60mmHg, PaCO2 >50 mm Hg, hypoalbuminemia and age ≥80 was developed to predict death risk and showed good performance.

Conclusion

During severe COPD exacerbation, an EPR < 0.755 preceding therapy can predict worse outcomes in patients with an AECOPD.

Keywords:

• eosinophil
• COPD
• eosinophil to platelet ratio
• emergency department

Abbreviations

AECOPD, chronic obstructive pulmonary disease; NLR, neutrophil to lymphocyte ratio; PLR, platelet to lymphocyte ratio; ICU, intensive care unit; RR, relatively risk; ARF, acute respiratory failure; EPR, eosinophil to platelet ratio; LRTI, lower respiratory tract infection; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; forced expiratory rate of the 1st second (FEV1%); LOH, length of hospitalization; ED, emergency department; IQR, interquartile range; ROC, receiver operating characteristic curve; AUC, area under the curves; LASSO, least absolute shrinkage selection operator; OCS, oral corticosteroids; OR, odds ratio.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Ethics Approval and Informed Consent

The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Dalian Friendship Municipal Hospital (protocol code YY-LL-2021-050, date of approval: 2021.12.31). Due to no specific patient identifiable information was used, patient consent was officially waived by the Ethics Committees of Dalian Municipal Friendship Hospital.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This work was funded by the National Natural Science Foundation of China (82370029, 82070030), and the Basic and Applied Basic Research Foundation of Guangdong province (2022A1515012064, 2023A1515010406).