Affiliations: Shaikh Zayed Medical Complex, (SZMC), Lahore,
Pakistan | The Providence Heart and Lung Institute, St. Paul's
Hospital, The University of British Columbia, BC, Canada | National Health Research Complex (NHRC), SZMC, Lahore,
Pakistan
Note: [] Corresponding author: Dr. Tania Ahmed Shakoori. E-mail:
[email protected]
Abstract: Background: There is a paucity of lung specific biomarkers to
diagnose exacerbations of chronic obstructive pulmonary disease (COPD) and to
track their progression. Surfactant protein D (SP-D) is a pulmonary collectin
regulating the innate immunity of the lung and its serum expression is
perturbed in COPD. However, it is not known whether serum levels change during
exacerbations. We sought to determine whether serum SP-D levels are raised in
COPD exacerbations. Objectives: To determine whether or not patients with exacerbations
have elevated serum SP-D levels compared with asymptomatic controls, stable
disease. Study design: case control study. Methods: We measured serum SP-D levels from patients with stable
COPD (n= 14), patients experiencing acute exacerbations (n=13) and in control
subjects (n=54) using a specific immunoassay and compared the levels using
analysis of variance. Results: Serum SP-D levels were significantly increased in patients
who experienced an acute exacerbation (227 ± 120 ng/mL) compared to
patients with stable disease (151 ± 83 ng/mL) or control subjects (128
± 65 ng/mL; p=0.003). Serum SP-D levels were also found to be inversely
related to various lung function parameters including
FEV_{1}/FVC% predicted. Conclusions: Our study suggests that serum SP-D levels are increased
in patients during exacerbations and may be a potential diagnostic biomarker
for COPD exacerbations.
Keywords: Surfactant protein D, serum biomarker, COPD, exacerbations, diagnostic
