title: Evaluation of full-length, cleaved and nitrosylated serum surfactant protein D as biomarkers for COPD.
abstract: Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is characterized by partially reversible airflow obstruction. Serum surfactant protein D (SP-D) is synthesized by type II pneumocytes and Clara cells and participates in surfactant homeostasis and pulmonary host defense. Serum levels of SP-D are raised in individuals with COPD but there is no correlation between the serum level of SP-D and the severity of airflow obstruction. Serum SP-D is present in different forms that may have more utility as a biomarker for COPD. We report here the development of new monoclonal antibodies to full length and cleaved SP-D. We have assessed these and existing antibodies in 98 individuals with COPD recruited to the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) cohort. Our data show that neither monoclonal antibodies to full length nor cleaved SP-D provide additional information over that obtained with a polyclonal antibody. Moreover, levels of serum nitrosylated-SP-D did not correlate with serum level of SP-D or any clinical phenotype of COPD. The measurement of modified SP-D is of limited value in characterising individuals with COPD.
authors.affiliation: Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Cambridge, UK.
authors.forename: Annelyse
authors.initials: A
authors.lastname: Duvoix
authors.forename: Elena
authors.initials: E
authors.lastname: Miranda
authors.forename: Juan
authors.initials: J
authors.lastname: Perez
authors.forename: Grith L
authors.initials: GL
authors.lastname: Sorensen
authors.forename: Uffe
authors.initials: U
authors.lastname: Holmskov
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Trapnell
authors.forename: Jens
authors.initials: J
authors.lastname: Madsen
authors.forename: Howard W
authors.initials: HW
authors.lastname: Clark
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Edwards
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Miller
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Tal-Singer
authors.forename: David A
authors.initials: DA
authors.lastname: Lomas
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005541:Forced Expiratory Volume; D006801:Humans; D051379:Mice; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood* / Q000276:immunology*; D018709:Statistics, Nonparametric; D014797:Vital Capacity
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D037663:Pulmonary Surfactant-Associated Protein D