title: Increased plasma concentration of surfactant protein D in chronic periodontitis independent of SFTPD genotype: potential role as a biomarker.
abstract: Surfactant protein (SP) D belongs to the family of collectins, which are humoral molecules of the innate immune system. Collectins belong to pattern recognition receptors and are present in plasma and on mucosal surfaces and recognize several microbial components, the pathogen-associated molecular patterns (PAMPs). While SP-A is primarily expressed in the lung, expression of SP-D is more widely detected including different mucosal surfaces and in serum. Therefore, SP-D is considered a functional candidate in chronic periodontitis. The present study sought to investigate whether plasma concentration of SP-D is altered in chronic periodontitis and whether polymorphisms within the SFTPD gene (Met11Thr, Ala160Thr and Ser270Thr) are associated with chronic periodontitis. The study population comprised 105 patients with chronic periodontitis and 122 healthy, unrelated control individuals. SP-D Plasma concentrations were determined using enzyme-linked immunosorbent assay test. Genotyping of SFTPD polymorphisms was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. Plasma concentrations were significantly increased in patients with chronic periodontitis compared with the controls. The median plasma concentrations were 81.6 ng/ml in the patients and 52.6 ng/ml in the controls (P = 0.00051). In contrast, the three SFTPD polymorphisms displayed no significant association with chronic periodontitis; thus, the increased plasma concentrations were independent on the genotype. The study showed significantly increased SP-D plasma concentrations in patients with chronic periodontitis compared with healthy controls. Thus, SP-D can potentially be used as a biomarker for chronic periodontitis. As no significant associations of SFTPD gene polymorphisms could be detected, other mechanisms influencing SP-D serum/plasma expression might exist.
authors.affiliation: Department of Preventive Dentistry and Periodontology, University of Munich, Munich, Germany. juergen.glas@med.uni-muenchen.de
authors.forename: J
authors.initials: J
authors.lastname: Glas
authors.forename: V
authors.initials: V
authors.lastname: Beynon
authors.forename: B
authors.initials: B
authors.lastname: Bachstein
authors.forename: J
authors.initials: J
authors.lastname: Steckenbiller
authors.forename: V
authors.initials: V
authors.lastname: Manolis
authors.forename: A
authors.initials: A
authors.lastname: Euba
authors.forename: B
authors.initials: B
authors.lastname: Müller-Myhsok
authors.forename: M
authors.initials: M
authors.lastname: Folwaczny
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution / Q000235:genetics; D015415:Biomarkers / Q000097:blood*; D002908:Chronic Disease; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000097:blood* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood* / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics*
chemical_list: D015415:Biomarkers; D037663:Pulmonary Surfactant-Associated Protein D