Serum Soluble Urokinase-Type Plasminogen Activator Receptor: A Promising Biomarker for Stable Chronic Obstructive Pulmonary Disease Patients.

Background Chronic obstructive pulmonary disease (COPD) is a condition in which airflow limitation becomes irreversible over time, often resulting from long-term exposure to environmental pollutants, harmful particles, smoke, and biomass fuel. Beyond FEV1, identifying a more specific biomarker to predict COPD progression remains a challenge. Soluble urokinase-type plasminogen activator receptor (suPAR) expression increases in the respiratory epithelial cells of COPD patients. This study aimed to evaluate serum suPAR levels across different grades of stable COPD patients. Methods Two hundred stable COPD patients (148 males and 52 females) were recruited after obtaining informed consent. Blood samples were collected, and serum suPAR levels were measured in all participants. Results Serum suPAR levels were elevated in COPD patients at Global Initiative for Obstructive Lung Disease (GOLD) stages IV and III (6.38 ± 0.05 ng/ml and 5.82 ± 0.18 ng/ml, respectively) compared to those at GOLD stages II and I (5.15 ± 0.25 ng/ml and 4.17 ± 0.29 ng/ml). A one-way ANOVA confirmed that the differences between groups were statistically significant (F = 428.83, p < 0.001). Conclusions This study suggests that serum suPAR levels can serve as a diagnostic marker for COPD. As low-grade pulmonary inflammation increases with disease severity, suPAR levels also rise. Additionally, this marker may be useful for monitoring the prognosis of stable COPD and assessing treatment response.