title: Surfactant protein D, a clinical biomarker for chronic obstructive pulmonary disease with excellent discriminant values.
abstract: Biological markers can help to better identify a disease or refine its diagnosis. In the present study, the association between surfactant protein D (SP-D) and chronic obstructive pulmonary disease (COPD) was studied among subjects consulting for respiratory diseases or symptoms and was compared with C-reactive protein (CRP) and fibrinogen. A further aim of this study was to identify the optimal cut-off point of SP-D able to discriminate COPD patients. A case-control study including 90 COPD patients, 124 asthma patients and 180 controls was conducted. Standardized questionnaires were administered and lung function tests were performed. Biological markers were measured in blood samples according to standardized procedures. The association between SP-D and COPD was investigated using logistic regression models. Receiver-operating characteristic curves were used for threshold identification. SP-D levels above the median value were positively associated with COPD [adjusted odds ratio (OR)=3.86, 95% confidence interval (CI): 1.51-9.85, P=0.005). No associations with COPD or asthma were found for CRP or fibrinogen levels. Scores for COPD diagnosis in all COPD patients or ever-smoker COPD patients were identified (sensitivity, 76.4 and 77.8%; specificity, 89.3 and 88.5%, respectively). The results indicate that SP-D can differentiate COPD from other respiratory symptoms or diseases. Used with socio-demographic characteristics and respiratory symptoms, SP-D is able to discriminate COPD patients from controls, particularly among smokers.
authors.affiliation: INSERM, VIMA: Aging and Chronic Diseases, Epidemiological and Public Health Approaches, U1168, F-94807 Villejuif, France; University of Versailles Saint-Quentin-en-Yvelines, F-94807 Villejuif, France; University of Paris-Sud, F-94270 Paris, France; Laboratory of Immunology, Faculty of Public Health, Doctoral School for Sciences and Technology, Lebanese University, 90656 Jdeidet El Metn, Lebanon; Clinical and Epidemiological Research Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 6573-14, Lebanon.
authors.forename: Zeina
authors.initials: Z
authors.lastname: Akiki
authors.affiliation: Laboratory of Immunology, Faculty of Public Health, Doctoral School for Sciences and Technology, Lebanese University, 90656 Jdeidet El Metn, Lebanon; Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark; Laboratory of Histology, Cellular and Molecular Biology and Immunology, Faculty of Sciences II, Lebanese University, 90656 Jdeidet El Metn, Fanar, Lebanon.
authors.forename: Dalia
authors.initials: D
authors.lastname: Fakih
authors.affiliation: Laboratory of Immunology, Faculty of Public Health, Doctoral School for Sciences and Technology, Lebanese University, 90656 Jdeidet El Metn, Lebanon; Laboratory of Histology, Cellular and Molecular Biology and Immunology, Faculty of Sciences II, Lebanese University, 90656 Jdeidet El Metn, Fanar, Lebanon.
authors.forename: Rania
authors.initials: R
authors.lastname: Jounblat
authors.affiliation: Laboratory of Immunology, Faculty of Public Health, Doctoral School for Sciences and Technology, Lebanese University, 90656 Jdeidet El Metn, Lebanon; Faculty of Medicine, Lebanese University, Beirut 6573-14, Lebanon.
authors.forename: Soulaima
authors.initials: S
authors.lastname: Chamat
authors.affiliation: Saint George Hospital University Medical Center, Beirut 1100-2807, Lebanon; Faculty of Medicine, Balamand University, Beirut 1100-2807, Lebanon.
authors.forename: Mirna
authors.initials: M
authors.lastname: Waked
authors.affiliation: Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark.
authors.forename: Uffe
authors.initials: U
authors.lastname: Holmskov
authors.affiliation: Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, DK-5000 Odense C, Denmark.
authors.forename: Grith L
authors.initials: GL
authors.lastname: Sorensen
authors.affiliation: INSERM, VIMA: Aging and Chronic Diseases, Epidemiological and Public Health Approaches, U1168, F-94807 Villejuif, France; University of Versailles Saint-Quentin-en-Yvelines, F-94807 Villejuif, France.
authors.forename: Rachel
authors.initials: R
authors.lastname: Nadif
authors.affiliation: Laboratory of Immunology, Faculty of Public Health, Doctoral School for Sciences and Technology, Lebanese University, 90656 Jdeidet El Metn, Lebanon; Clinical and Epidemiological Research Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 6573-14, Lebanon.
authors.forename: Pascale
authors.initials: P
authors.lastname: Salameh
keywords: asthma; chronic obstructive pulmonary disease; plasma fibrinogen; serum C-reactive protein; serum surfactant protein D