Related Experiment Video
Updated: Jan 1, 2026
Methodology for Sputum Induction and Laboratory Processing
Published on: December 17, 2017
Differential DAMP release was observed in the sputum of COPD, asthma and asthma-COPD overlap (ACO) patients
Xiaolin Huang1, Xiaoyu Tan2, Yue Liang3
1Department of intensive care unit, The second affiliated hospital of Guangxi Medical University, Nanning, 530021, China.
Abstract:
Asthma-COPD overlap (ACO) has been under intensive focus; however, the levels of damage-associated molecular patterns (DAMPs) that can activate the innate and adaptive immune responses of ACO are unknown. The present study aimed to examine the levels of some DAMPs in asthma, COPD, and ACO and to identify the associations between clinical characteristics and DAMPs in ACO. Sputum from subjects with asthma (n = 87) or COPD (n = 73) and ACO (n = 68) or from smokers (n = 62) and never-smokers (n = 62) was analyzed for high mobility group protein B1 (HMGB1), heat shock protein 70 (HSP70), LL-37, S100A8, and galectin-3 (Gal-3). The concentration of HMGB1, HSP70, LL-37, and S100A8 proteins in sputum from ACO patients was significantly elevated, whereas that of Gal-3 was reduced, compared to that of smokers and never-smokers. The levels of HMGB1 and Gal-3 proteins in ACO patients were elevated compared to those in asthma patients. The sputum from ACO patients showed an increase in the levels of LL-37 and S100A8 proteins compared to that of asthma patients, whereas the levels decreased compared to those of COPD patients. The concentrations of HMGB1, HSP70, LL-37, and S100A8 proteins in the sputum of 352 participants were negatively correlated, whereas the levels of Gal-3 were positively correlated, with FEV1, FEV1%pred, and FEV1/FVC. Sputum HMGB1 had a high AUC of the ROC curve while distinguishing ACO patients from asthma patients. Meanwhile, sputum LL-37 had a high AUC of the ROC curve in differentiating asthma and COPD. The release of sputum DAMPs in ACO may be involved in chronic airway inflammation in ACO; the sputum HMGB1 level might serve as a valuable biomarker for distinguishing ACO from asthma, and the sputum LL-37 level might be a biomarker for differentiating asthma and COPD.
Insights
Damage-associated molecular patterns (DAMPs) like HMGB1 and LL-37 are elevated in Asthma-COPD overlap (ACO) sputum. These DAMPs may indicate airway inflammation and serve as biomarkers to distinguish ACO from asthma and COPD.
Area of Science:
- Respiratory Medicine
- Immunology
- Biomarker Discovery
Background:
- Asthma-COPD overlap (ACO) is a significant clinical entity, but the role of damage-associated molecular patterns (DAMPs) in its pathogenesis remains unclear.
- DAMPs are crucial in activating innate and adaptive immune responses, potentially contributing to chronic airway inflammation in respiratory diseases.
Purpose of the Study:
- To investigate the levels of specific DAMPs (HMGB1, HSP70, LL-37, S100A8, Gal-3) in the sputum of patients with asthma, COPD, and ACO.
- To identify associations between DAMP levels and clinical characteristics in ACO patients.
- To evaluate the potential of DAMPs as biomarkers for differentiating these respiratory conditions.
Main Methods:
- Sputum samples were collected from 352 participants across asthma, COPD, ACO, smoker, and never-smoker groups.
- Levels of HMGB1, HSP70, LL-37, S100A8, and Gal-3 were quantified using immunoassay techniques.
- Statistical analyses, including correlation with lung function parameters (FEV1, FEV1%pred, FEV1/FVC) and ROC curve analysis, were performed.
Main Results:
- Sputum concentrations of HMGB1, HSP70, LL-37, and S100A8 were significantly elevated in ACO patients compared to smokers and never-smokers, while Gal-3 was reduced.
- ACO patients showed higher HMGB1 and Gal-3 levels than asthma patients, and higher LL-37 and S100A8 levels than asthma patients, but lower than COPD patients.
- Sputum HMGB1 and LL-37 demonstrated high AUC values in ROC analyses, distinguishing ACO from asthma and differentiating asthma from COPD, respectively. DAMP levels negatively correlated with lung function.
Conclusions:
- Elevated sputum DAMPs, including HMGB1, HSP70, LL-37, and S100A8, are characteristic of ACO and may contribute to chronic airway inflammation.
- Sputum HMGB1 shows potential as a biomarker for distinguishing ACO from asthma.
- Sputum LL-37 may serve as a biomarker for differentiating asthma from COPD.
More Related Videos
04:53Author Spotlight: Traditional Chinese Medicine for Sleep Disorders in Acute COPD — A Safe, Cost-Effective Approach
Published on: October 18, 2024
04:03Author Spotlight: Evaluating the Therapeutic Efficacy of Moving Cupping Along Meridians for Acute Exacerbation of COPD
Published on: September 27, 2024
Related Concept Videos
01:26COPD: Management Using Bronchodilators and Corticosteroids
01:22Chronic Obstructive Pulmonary Disease
Smoking is a primary risk factor for COPD, with over 80% of patients having a history of it. Patients typically experience progressive dyspnea or labored breathing, frequent coughing, and recurrent pulmonary infections. Many eventually succumb to respiratory failure, characterized by...
01:27Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
01:20Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
01:20COPD: Pathogenesis and Clinical Features
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...