title: [Titer and avidity of serum antibody to Porphyromonas gingivalis before and after periodontal therapy].
abstract: OBJECTIVE
  To observe the changes of titer and avidity of serum antibody to Porphyromonas gingivalis (Pg) before and one month after periodontal therapy, and to observe the correlation of titer and avidity of anti-Pg IgG with clinical indices.
  
  
  METHODS
  ELISA and DEA-ELISA were used to determine the titer and avidity of serum IgG antibody to Pg381 before and one month after periodontal treatment in 17 periodontitis patients and 6 healthy control subjects.
  
  
  RESULTS
  The titers of anti-Pg IgG antibody were higher in periodontitis patients than in healthy control subjects (P < 0.001). All patients were seropositive (titers to Pg were higher than 2-fold above the median for control subjects). IgG antibody avidity to Pg in periodontitis patients were not found to be significantly lower than that in control group. The titers to Pg decreased significantly at one month after periodontal therapy, but antibody avidity didn't change. Serum anti-Pg antibody titers had a tendency of negative correlation with probing depth. The antibody titers were significant higher in periodontitis patients with < or = 5 mm mean probing depth than in patients with > 5 mm mean probing depth.
  
  
  CONCLUSIONS
  It is suggested that the humoral immune response to Pg381 is protective and this protective effect mainly depends on the titer of antibody.
authors.affiliation: Department of Periodontology, School of Stomatology, Beijing Medical University, Beijing 100081, China.
authors.forename: X
authors.initials: X
authors.lastname: Ouyang
authors.forename: C
authors.initials: C
authors.lastname: Cao
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000915:Antibody Affinity; D016866:Bacteroidaceae Infections / Q000097:blood / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D010518:Periodontitis / Q000097:blood / Q000382:microbiology* / Q000628:therapy; D016966:Porphyromonas gingivalis / Q000276:immunology*; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial