Background: Pentraxin 3 (PTX3) is an acute-phase protein and an important inflammatory mediator. We hypothesized plasma PTX3 could be a valuable diagnostic biomarker in acute exacerbation of chronic obstructive pulmonary disease (AECOPD).
Methods: In this prospective controlled study, 458 COPD patients and 71 healthy controls from May 2019 to December 2020 in two hospitals were enrolled. COPD patients were divided into AECOPD group (n = 173) and stable COPD group (n = 285). AECOPD patients were subdivided into mild or moderate group (n = 43) and severe group (n = 130) based on severity. Plasma PTX3 levels were detected by ELISA.
Results: Plasma PTX3 levels were significantly higher in AECOPD (2.8 ng/mL) compared to stable COPD (0.87 ng/mL) and healthy controls (0.83 ng/mL). In the analysis of AECOPD subgroups, plasma PTX3 level of severe group (4.51 ng/mL) was significantly higher than that of mild or moderate group (1.25 ng/mL). Patients with respiratory failure had higher PTX3 than those without respiratory failure. No difference was observed between stable COPD patients and healthy controls. ROC analysis showed that plasma PTX3 had a considerable ability to distinguish AECOPD from stable COPD [AUC: 0.85, 95% CI (0.81– 0.88), P < 0.0001; cut-off 1.25 ng/mL, sensitivity 77.5%, specificity 74%]. AUC of PTX3 was better than CRP regarding diagnosis of AECOPD. Combination of PTX3 and CRP was superior to either of them in diagnosing AECOPD.
Conclusion: Plasma PTX3 levels were significantly higher in AECOPD than stable COPD. The level was associated with the severity of exacerbation. Plasma PTX3 has potential value as a biomarker to diagnose and evaluate AECOPD.
Keywords: pentraxin 3, AECOPD, diagnosis, severity, C-reactive protein