Ruzena Tkacova1, Annette McWilliams, Stephen Lam, Don D Sin. 1. Department of Respiratory Medicine and Tuberculosis, Faculty of Medicine, P.J. Safarik University and L. Pasteur Teaching Hospital, Kosice, Slovakia. ruzena.tkacova@upjs.sk
Abstract
BACKGROUND: Surfactant protein D (SP-D) is a promising blood biomarker in patients with chronic obstructive pulmonary disease (COPD). Nevertheless, circulating levels of SP-D are not related to pulmonary functions. In the present exploratory study, we created a simple index of plasma to bronchoalveolar lavage (BAL) fluid ratio of SP-D (pSP-D/bSP-D), and determined whether this index would relate to the severity of airflow limitation and hence represent a superior biomarker than pSP-D alone. MATERIAL/ METHODS: In 50 ex and current smokers (mean age 57.6±7.8 years, 74% men), SP-D was measured in BAL fluid and plasma samples, and the relationships between spirometric variables and a composite parameter - the pSP-D/bSP-D ratio were determined. RESULTS: There was a significant inverse correlation between the pSP-D/bSP-D ratio and the severity of airflow obstruction, as measured by FEV1/FVC (p=0.012). In contrast, no relationship was observed between FEV1/FVC and pSP-D alone. CONCLUSIONS: We suggest that integrating both lung and plasma expression of pneumo-proteins may be more useful than plasma expression alone in developing pneumo-proteins as potential biomarkers in COPD.
BACKGROUND:Surfactant protein D (SP-D) is a promising blood biomarker in patients with chronic obstructive pulmonary disease (COPD). Nevertheless, circulating levels of SP-D are not related to pulmonary functions. In the present exploratory study, we created a simple index of plasma to bronchoalveolar lavage (BAL) fluid ratio of SP-D (pSP-D/bSP-D), and determined whether this index would relate to the severity of airflow limitation and hence represent a superior biomarker than pSP-D alone. MATERIAL/ METHODS: In 50 ex and current smokers (mean age 57.6±7.8 years, 74% men), SP-D was measured in BAL fluid and plasma samples, and the relationships between spirometric variables and a composite parameter - the pSP-D/bSP-D ratio were determined. RESULTS: There was a significant inverse correlation between the pSP-D/bSP-D ratio and the severity of airflow obstruction, as measured by FEV1/FVC (p=0.012). In contrast, no relationship was observed between FEV1/FVC and pSP-D alone. CONCLUSIONS: We suggest that integrating both lung and plasma expression of pneumo-proteins may be more useful than plasma expression alone in developing pneumo-proteins as potential biomarkers in COPD.
Authors: Carla Winkler; Elena N Atochina-Vasserman; Olaf Holz; Michael F Beers; Veit J Erpenbeck; Norbert Krug; Stefan Roepcke; Gereon Lauer; Martin Elmlinger; Jens M Hohlfeld Journal: Respir Res Date: 2011-03-11