Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR) and Monocyte-to-Lymphocyte Ratio (MLR) as Biomarkers in Diagnosis Evaluation of Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective, Observational Study

Abstract

Purpose

Hierarchical management is advocated in China to effectively manage chronic obstructive pulmonary disease (COPD) patients and reduce the incidence and mortality of acute exacerbation of COPD (AE-COPD). However, primary and community hospitals often have limited access to advanced equipment and technology. Complete blood count (CBC), which is commonly used in these hospitals, offers the advantages of being cost-effective and easily accessible. This study aims to evaluate the significance of routine blood indicators in aiding of diagnosing AE-COPD.

Patients and Methods

In this research, we enrolled a total of 112 patients diagnosed with AE-COPD, 92 patients with stable COPD, and a control group comprising 60 healthy individuals. Clinical characteristics, CBC parameters, and serum CRP levels were collected within two hours. To assess the associations between NLR/PLR/MLR and CRP by Spearman correlation test. The diagnostic accuracy of NLR, PLR and MLR in AE-COPD was assessed using Receiver Operating Characteristic Curve (ROC) and the area under the curve (AUC). Binary Logistic Regression analysis was conducted for the indicators of NLR, PLR and MLR.

Results

We found that patients with AE-COPD had significantly higher levels of NLR, PLR and MLR in contrast to patients with stable COPD. Additionally, the study revealed a noteworthy correlation between CRP and NLR (rs=0.5319, P<0.001), PLR (rs=0.4424, P<0.001), and MLR (rs=0.4628, P<0.001). By utilizing specific cut-off values, the amalgamation of NLR, PLR and MLR augmented diagnostic sensitivity. Binary logistic regression analysis demonstrated that heightened NLR and MLR act as risk factors for the progression of AE-COPD.

Conclusion

The increasing levels of NLR, PLR and MLR could function as biomarkers, akin to CRP, for diagnosis and assessment of acute exacerbations among COPD patients. Further research is required to validate this concept.

Graphical Abstract

Keywords:

• acute exacerbation of chronic obstructive pulmonary disease
• AE-COPD
• neutrophil-lymphocyte ratio
• NLR
• platelet-lymphocyte ratio
• PLR
• monocyte-lymphocyte ratio
• MLR

Ethics Statement

The study protocol was reviewed and approved by the Zhongshan Tanzhou People’s Hospital Clinical Research and Animal Experimentation Ethic Committee (Approval No. 2020001) and was conducted in accordance with the 1964 Declaration of Helsinki and its subsequent amendments or similar ethical standards. This study was a retrospective study that did not involve the disclosure of patients’ private information, and informed consent was waived by our institutional review board. I solemnly promise to strictly comply with relevant laws and regulations to ensure the security and confidentiality of patients’ information and to respect their right to privacy. I am well aware that any information that identifies a patient is sensitive information, and therefore I promise not to disclose any patient identifying information in public information.

Acknowledgments

The authors would like to acknowledge the personnel of the Department of Laboratory Medicine, Tanzhou People’s Hospital of Zhongshan for their assistance for this study. The authors would like to acknowledge Health Commission of Guangdong Province (A2020389) and Zhongshan Science and Technology Bureau (2022B1073) funding for this study.

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.