Serum Cytokeratin 18 and Fragment as Biomarkers for Severity and Prognosis in Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Abstract

Background: Cytokeratin (CK)18 is present in the bronchi and alveolar epithelium of the lung, and its cleavage product, CK-18M30, serves as a biological marker of apoptosis. However, the specific roles of CK-18 and CK-18M30 in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remain unclear.

Methods: This study enrolled 289 patients with AECOPD who met the inclusion criteria. Demographic information and clinical characteristics of the patients were documented. A 3-year follow-up period was implemented to evaluate acute exacerbations and mortality. Serum CK-18 and CK-18M30 concentrations were measured using enzyme-linked immunosorbent assays.

Results: Serum concentrations of CK-18/CK-18M30 at admission in patients with AECOPD were higher than those in the control group. As severity increased, serum CK-18/CK-18M30 levels increased progressively in AECOPD patients. Pearson's correlation analysis revealed that serum CK-18/CK-18M30 concentrations were positively correlated with several clinical parameters. Linear and logistic regression models demonstrated positive correlations between serum CK-18 and CK-18M30 levels at admission and severity scores. Furthermore, higher serum CK-18/CK-18M30 levels at admission were associated with increased frequency of death and acute exacerbation in patients with AECOPD within 3 years.

Conclusion: Serum CK-18/CK-18M30 levels at admission were positively correlated with severity and poor prognosis in patients with AECOPD within 3 years. Therefore, serum CK-18 and CK-18M30 concentrations may serve as novel diagnostic and prognostic biomarkers for patients with AECOPD.