The role of serum surfactant protein D as a biomarker of exacerbation of chronic obstructive pulmonary disease

Abstract EN

Background: The exacerbation of chronic obstructive pulmonary disease (COPD) is a major factor for the high mortality associated with the disease.

There is a paucity in the lung-specific biomarkers which diagnose these exacerbations.

Surfactant protein D (SP-D) is a promising biomarker in predicting clinical outcomes for patients with COPD, is lung-specific and can be detected in serum.

However, the profile in which serum concentrations of SP-D change during acute exacerbation is still unclear.

This study aims to estimate and compare the concentrations of serum SP-D in patients with stable disease and during the exacerbation.

Methods: A cross-sectional study was conducted which composed of apparently healthy individuals (n ¼ 28), which included 14 smokers and 14 nonsmokers, patients with stable COPD (n ¼ 28), and patients experiencing acute exacerbations (n ¼ 28).

Pulmonary functions were performed for all groups.

Serum SP-D concentrations were measured using enzyme-linked immunosorbent assay (ELISA).

These concentrations were compared by analysis of variance.

Results: Serum SP-D levels were significantly elevated in patients with acute exacerbations (508.733 ^ 102.813 ng/ml) compared to patients with stable COPD (337.916 ^ 86.265 ng/ml) and healthy subjects (177.313 ^ 46.998 ng/ml; p , 0.001).

Serum SP-D levels correlated inversely with lung function parameters including FEV1%pred, FVC%pred and FEV1/FVC.

Conclusion: Serum SP-D levels are raised early on during acute exacerbations of COPD, which could be a potential early diagnostic biomarker for COPD exacerbations Keywords: chronic obstructive pulmonary disease (COPD), serum biomarker, COPD exacerbations, COPD diagnosis, surfactant protein D (SP-D)