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

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.

Serum legumain is a potential biomarker for community-acquired pneumonia: a prospective cohort study.

Legumain is a cysteine endopeptidase that belongs to the C13 family. Many studies have revealed that legumain plays a vital pathogenic role in various respiratory diseases. The aim of this study was to explore the role of legumain in community-acquired pneumonia (CAP).