Determinants of serum IgG responses to periodontal bacteria in a nationally representative sample of US adults.

AIM: To assess the distribution of elevated antibody titres to multiple periodontal bacteria, including established/putative pathogens and health-related species, by selected demographic, behavioural, and oral- and general health-related characteristics. METHODS: Data from 8153 >or=40-year-old participants from the third National Health and Nutrition Examination Survey were used, including 1588 edentulous individuals. We used checkerboard immunoblotting to assess serum IgG levels to 19 periodontal species. Thresholds for elevated antibody responses were defined for each species using the 90th percentile titre in periodontal healthy participants, using two alternative definitions of periodontitis. RESULTS: Edentulous individuals showed lower antibody responses than dentate participants, notably for titres to "red complex" species and Actinobacillus actinomycetemcomitans. Elevated titres to Porphyromonas gingivalis were twice as prevalent in participants with periodontitis than in periodontal healthy individuals. Non-Hispanic blacks and Mexican-Americans were more likely to display elevated titres for P. gingivalis compared with non-Hispanic whites (22.9%versus 19.4%versus 9.5%). Current smokers were significantly less likely to exhibit high titres to multiple bacteria than never smokers. CONCLUSION: Demographic, behavioural, and oral- and general health-related characteristics were strong determinants of systemic antibody responses to periodontal bacteria in a nationally representative sample of US adults.

Heterogeneity of systemic inflammatory responses to periodontal therapy.

AIMS: We investigated the effect of comprehensive periodontal therapy on the levels of multiple systemic inflammatory biomarkers. MATERIAL AND METHODS: Thirty patients with severe periodontitis received comprehensive periodontal therapy within a 6-week period. Blood samples were obtained at: 1-week pre-therapy (T1), therapy initiation (T2), treatment completion (T3), and 4 weeks thereafter (T4). We assessed the plasma concentrations of 19 biomarkers using multiplex assays, and serum IgG antibodies to periodontal bacteria using checkerboard immunoblotting. At T2 and T4, dental plaque samples were analysed using checkerboard hybridizations. RESULTS: At T3, PAI-1, sE-selectin, sVCAM-1, MMP-9, myeloperoxidase, and a composite summary inflammatory score (SIS) were significantly reduced. However, only sE-selectin, sICAM, and serum amyloid P sustained a reduction at T4. Responses were highly variable: analyses of SIS slopes between baseline and T4 showed that approximately 1/3 and 1/4 of the patients experienced a marked reduction and a pronounced increase in systemic inflammation, respectively, while the remainder were seemingly unchanged. Changes in inflammatory markers correlated poorly with clinical, microbiological and serological markers of periodontitis. CONCLUSIONS: Periodontal therapy resulted in an overall reduction of systemic inflammation, but the responses were inconsistent across subjects and largely not sustainable. The determinants of this substantial heterogeneity need to be explored further.

Serum antibodies to periodontal bacteria as diagnostic markers of periodontitis.

BACKGROUND: Assessment of periodontal conditions in epidemiologic studies usually requires a clinical examination, which is resource-intensive. We investigated the ability of serum immunoglobulin G (IgG) antibodies to periodontal bacteria to reflect clinical periodontal status. METHODS: We used checkerboard immunoblotting to assess serum IgG levels to 19 species, including established/putative periodontal pathogens and non-pathogenic bacteria, in 5,747 dentate adults aged > or = 40 years who participated in the third National Health and Nutrition Examination Survey between 1988 and 1994. Three earlier described alternative definitions of periodontitis were used, based on specific combinations of probing depth and attachment level values. Optimized elevated titer thresholds and corresponding sensitivities and specificities were calculated for each definition. Titers significantly associated with periodontitis were identified in univariable and multivariable logistic regression models. Parsimonious models were subsequently developed using age, gender, race/ethnicity, education, smoking, and diagnosed diabetes. RESULTS: In unadjusted models, high titers to Porphyromonas gingivalis were most strongly associated with periodontitis across all definitions (odds ratio, 2.07 to 2.74; P <0.05). In parsimonious models including demographic data, smoking, and diagnosed diabetes, high P. gingivalis titers were consistently associated with periodontitis, whereas high Eubacterium nodatum titers were associated with periodontal health in two of three definitions. Receiver operating characteristic curves for the parsimonious multivariable models showed that the area under the curve ranged between 0.72 and 0.78. CONCLUSIONS: Serum IgG titers to selected periodontal species, combined with demographic and behavioral characteristics, resulted in a moderately accurate classification of periodontal status in epidemiologic studies. The external validity of these findings must be examined further.

Markers of periodontal infection and preterm birth.

OBJECTIVE: This study was undertaken to explore the relationship between clinical, microbiologic, and serologic markers of periodontitis and preterm birth (PTB). STUDY DESIGN: We compared women with a singleton gestation giving birth before the 37th week (cases, n = 83) with term delivery controls (n = 120). Periodontal examination and collection of dental plaque and blood samples were performed within 48 hours after delivery. Microbial levels and maternal immunoglobulin G titers to oral bacteria were analyzed. Multivariate regression models were fitted controlling for common covariates. RESULTS: Cases showed greater mean attachment loss (1.7 vs 1.5 mm, P = .003) and higher prevalence of periodontitis (30.1% vs 17.5%, P = .027). No differences in microbial or serum antibody levels were detected between the groups. Logistic regression revealed that PTB was associated with attachment loss (adjusted odds ratio: 2.75, 95% CI: 1.01-7.54). Linear regression indicated a significant ( P = .04) association between attachment loss and low birth weight (LBW). CONCLUSION: The data support the notion that periodontitis is independently associated with PTB and LBW.

The Influence of Interleukin Gene Polymorphism on Expression of Interleukin-1ß and Tumor Necrosis Factor-α in Periodontal Tissue and Gingival Crevicular Fluid.

BACKGROUND: A specific composite genotype of the polymorphic interleukin-1 (IL-1) gene cluster has recently been associated with severe periodontitis. One polymorphism of the composite periodontitis-associated genotype (PAG) has been functionally linked with expression of high levels of IL-1. The purpose of this study was to test whether gingival crevicular fluid (GCF) levels of IL-1ß and tumor necrosis factor-alpha (TNFα), and gingival tissue levels of IL- 1α, IL-1ß, and TNFα correlate with PAG, and to examine the effec; of conservative periodontal therapy on these levels. METHODS: Twenty-two adults with moderate to advanced periodontal disease were enrolled. Polymerase chain reaction amplification and restriction enzymes were used to identify specific polymorphisms from peripheral blood samples. GCF samples were collected at baseline and 3 weeks following conservative treatment and analyzed by ELISA for IL-1ß and TNFα. An interproximal gingival biopsy was collected at baseline and follow-up and analyzed for IL-1α, IL-1ß, and TNFα by ELISA. RESULTS: The genotyping identified 7 as PAG(+) and 15 as PAG(-). The 2 groups were comparable in terms of existing periodontitis and age. In shallow sites (<4 mm), total IL-1ß in GCF was 2.5 times higher for PAG(+) patients prior to treatment (P = 0.03), and 2.2 times higher after treatment (P = 0.04), while differences were less apparent in deeper sites. Following treatment, a reduction in IL-1ß concentration in GCF was seen for PAG(-) but not for PAG(+) patients. While not statistically significant, a trend was observed in mean tissue levels of IL-1ß which were 3.6 times higher in PAG(+) versus PAG(-) patients (P = 0.09). CONCLUSIONS: These data suggest that PAG(+) patients may demonstrate phenotypic differences as indicated by elevated levels of IL-1ß in GCF. J Periodontol 1999;70:567-573.