Background: Endothelial cell-specific molecule (ESM)-1 is a soluble proteoglycan expressed by the vascular endothelium and which also circulates in the bloodstream. Inflammatory cytokines and proangiogenic growth factors increase its expression, and increased serum levels are found in immunocompetent patients with sepsis. The aim of this study was to investigate differential changes in plasma levels of ESM-1 before and after antibiotic treatment in hospitalized adult patients with community-acquired pneumonia (CAP).
Methods: Plasma ESM-1 levels were measured in 82 adult patients with CAP and 82 healthy controls using a commercial enzyme-linked immunosorbent assay (ELISA). Upon initial hospitalization, Acute Physiology and Chronic Health Evaluation II (APACHE II), CURB-65, and Pneumonia Severity Index (PSI) scores were determined to assess CAP severity in these patients.
Results: Results showed a decline in the number of white blood cells (WBCs) and neutrophils, and decreases in the concentrations of C-reactive protein (CRP) and ESM-1 after antibiotic treatment. The plasma concentration of ESM-1, but not CRP or the WBC count, was correlated with the severity of CAP based on the PSI (r=0.554, p<0.001), CURB-65 (r=0.510, p<0.001), and APACHE II scores (r=0.447, p<0.001).
Conclusions: Plasma levels of ESM-1 may be able to play a role in the diagnosis and clinical assessment of the severity of CAP, which could potentially guide the development of treatment strategies.