title: Clinical application of human β-defensin and CD14 gene polymorphism in evaluating the status of chronic inflammation.
abstract: BACKGROUND
  Periodontitis is a common disease that affects the periodontal tissue supporting the teeth. This disease is attributed to multiple risk factors, including diabetes, cigarette smoking, alcohol, pathogenic microorganisms, genetics and others. Human beta-defensin-1 (hBD-1) is a cationic antimicrobial peptide with cysteine-rich ß-sheets and broad-spectrum antimicrobial activity. CD14 is a protein involved in the detection of bacterial lipopolysaccharide (LPS) and has also been associated with periodontitis. This study investigates the single nucleotide polymorphic (SNP) region, -1654(V38I), of the human beta-defensin-1 (hBD-1) gene as well as the -159 region of the CD14 gene in subjects with chronic periodontitis.
  
  
  METHODS
  Blood samples from periodontally healthy subjects and periodontitis patients were obtained. DNA was extracted from the blood and was used to perform restriction digest at the polymorphic G1654A site of DEFB1 with the enzyme HincII. The polymorphic site 159TT of CD14 was digested with the enzyme AvaII. Enzyme-linked immunosorbent assay (ELISA) was performed on soluble samples to determine the protein expressions.
  
  
  RESULTS
  The control and patient groups expressed 35% and 38% 1654 A/A genotype of DEFB1, respectively. The A allele frequency of the control group was 40%, while the patient blood group was 54%. The mean hBD-1 protein levels of the control and patient samples were 102.83 pg/mL and 252.09 pg/mL, respectively. The genotype distribution of CD14 in healthy subjects was 16% for C/C, 26% for T/T and 58% for C/T. The genotype frequencies of CD14 in periodontitis patients were 10% for C/C, 43% for T/T and 47% for C/T. The CD14 protein expression determined by ELISA showed a mean protein level of the control samples at 76.28ng/mL and the patient blood samples at 179.27ng/mL with a p value of 0.001.Our study demonstrated that patients suffering from chronic periodontitis present more commonly with the 1654A/A genotype on the DEFB1 gene and the 159T/T genotype on the CD14 gene.
  
  
  CONCLUSIONS
  This study purely investigated the association between periodontitis and one polymorphic site on both DEFB1 and CD14 gene, with the purpose of expanding knowledge for the future development in diagnostic markers or therapeutic interventions to combat this disease.
authors.affiliation: UNIMED Medical Institute, Hong Kong SAR.
authors.forename: Wings T Y
authors.initials: WT
authors.lastname: Loo
authors.forename: Lan-jun
authors.initials: LJ
authors.lastname: Bai
authors.forename: Chang-bin
authors.initials: CB
authors.lastname: Fan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yue
authors.forename: Yi-ding
authors.initials: YD
authors.lastname: Dou
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Liang
authors.forename: Mary N B
authors.initials: MN
authors.lastname: Cheung
authors.forename: Louis  W C
authors.initials: L
authors.lastname: Chow
authors.forename: Jin-le
authors.initials: JL
authors.lastname: Li
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.forename: Liu
authors.initials: L
authors.lastname: Qing
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001483:Base Sequence; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000097:blood / Q000235:genetics*; D003710:Demography; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000235:genetics*; D018950:Lipopolysaccharide Receptors / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D015183:Restriction Mapping; D055815:Young Adult; D023083:beta-Defensins / Q000235:genetics*
chemical_list: C406407:DEFB1 protein, human; C106641:DEFB4A protein, human; D018950:Lipopolysaccharide Receptors; D023083:beta-Defensins