TY - JOUR
T1 - Comprehensive characterisation of pulmonary and serum surfactant protein D in COPD
AU - Winkler, Carla
AU - Atochina-Vasserman, Elena N.
AU - Holz, Olaf
AU - Beers, Michael F.
AU - Erpenbeck, Veit J.
AU - Krug, Norbert
AU - Roepcke, Stefan
AU - Lauer, Gereon
AU - Elmlinger, Martin
AU - Hohlfeld, Jens M.
PY - 2011/3/11
Y1 - 2011/3/11
N2 - Background: Pulmonary surfactant protein D (SP-D) is considered as a candidate biomarker for the functional integrity of the lung and for disease progression, which can be detected in serum. The origin of SP-D in serum and how serum concentrations are related to pulmonary concentrations under inflammatory conditions is still unclear.Methods: In a cross-sectional study comprising non-smokers (n = 10), young - (n = 10), elderly smokers (n = 20), and smokers with COPD (n = 20) we simultaneously analysed pulmonary and serum SP-D levels with regard to pulmonary function, exercise, repeatability and its quaternary structure by native gel electrophoresis. Statistical comparisons were conducted by ANOVA and post-hoc testing for multiple comparisons; repeatability was assessed by Bland-Altman analysis.Results: In COPD, median (IQR) pulmonary SP-D levels were lower (129(68) ng/ml) compared to smokers (young: 299(190), elderly: 296(158) ng/ml; p <0.01) and non-smokers (967(708) ng/ml; p <0.001). The opposite was observed in serum, with higher concentrations in COPD (140(89) ng/ml) as compared to non-smokers (76(47) ng/ml; p <0.01). SP-D levels were reproducible and correlated with the degree of airway obstruction in all smokers. In addition, smoking lead to disruption of the quaternary structure.Conclusions: Pulmonary and serum SP-D levels are stable markers influenced by smoking and related to airflow obstruction and disease state. Smaller subunits of pulmonary SP-D and the rapid increase of serum SP-D levels in COPD due to exercise support the translocation hypothesis and its use as a COPD biomarker.Trial registration: no interventional trial.
AB - Background: Pulmonary surfactant protein D (SP-D) is considered as a candidate biomarker for the functional integrity of the lung and for disease progression, which can be detected in serum. The origin of SP-D in serum and how serum concentrations are related to pulmonary concentrations under inflammatory conditions is still unclear.Methods: In a cross-sectional study comprising non-smokers (n = 10), young - (n = 10), elderly smokers (n = 20), and smokers with COPD (n = 20) we simultaneously analysed pulmonary and serum SP-D levels with regard to pulmonary function, exercise, repeatability and its quaternary structure by native gel electrophoresis. Statistical comparisons were conducted by ANOVA and post-hoc testing for multiple comparisons; repeatability was assessed by Bland-Altman analysis.Results: In COPD, median (IQR) pulmonary SP-D levels were lower (129(68) ng/ml) compared to smokers (young: 299(190), elderly: 296(158) ng/ml; p <0.01) and non-smokers (967(708) ng/ml; p <0.001). The opposite was observed in serum, with higher concentrations in COPD (140(89) ng/ml) as compared to non-smokers (76(47) ng/ml; p <0.01). SP-D levels were reproducible and correlated with the degree of airway obstruction in all smokers. In addition, smoking lead to disruption of the quaternary structure.Conclusions: Pulmonary and serum SP-D levels are stable markers influenced by smoking and related to airflow obstruction and disease state. Smaller subunits of pulmonary SP-D and the rapid increase of serum SP-D levels in COPD due to exercise support the translocation hypothesis and its use as a COPD biomarker.Trial registration: no interventional trial.
UR - http://www.scopus.com/inward/record.url?scp=79952477228&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952477228&partnerID=8YFLogxK
U2 - 10.1186/1465-9921-12-29
DO - 10.1186/1465-9921-12-29
M3 - Article
C2 - 21396106
AN - SCOPUS:79952477228
VL - 12
JO - Respiratory Research
JF - Respiratory Research
SN - 1465-9921
M1 - 29
ER -