Anti-cardiolipin antibodies in sera from patients with periodontitis.

Antiphospholipid antibodies are commonly found in patients with systemic lupus erythematosus or the antiphospholipid syndrome, and a subset of such antibodies is associated with prothrombotic events such as stroke and with adverse pregnancy outcomes and fetal loss. We examined sera from 411 patients who were clinically characterized as to their periodontal disease status for serum levels of beta2-glycoprotein I-dependent anti-cardiolipin autoantibodies (anti-CL). The prevalence of patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) positive for anti-CL (16.2% and 19.3%, respectively) was greater than that in healthy controls (NP) and localized aggressive periodontitis (LAgP) patients (6.8% and 3.2%). Patients with these autoantibodies demonstrated increased pocket depth and attachment loss compared with patients lacking the antibodies. Analysis of the data indicates that patients with generalized periodontitis have elevated levels of autoantibodies reactive with phospholipids. These antibodies could be involved in elevated risk for stroke, atherosclerosis, or pre-term birth in periodontitis patients.

Evidence of a substantial genetic basis for IgG2 levels in families with aggressive periodontitis.

IgG2 is elevated in localized but not in generalized aggressive periodontitis (AgP). Exposure to pathogenic bacteria is essential for disease. Immune responses are dominated by IgG2 reactive with bacterial surface carbohydrates. We used variance component analyses to assess IgG2 heritability and determine whether genes that influence IgG2 are the same genes that influence disease susceptibility. We studied 17 Caucasian and 43 African American families with two or more localized or generalized AgP-affected members (274 subjects with IgG2 measurements). Only 16% of the variance in IgG2 was attributable to age, race, and smoking. Even with the addition of localized AgP, the model still explained only 19% of IgG2 variance. By contrast, heritability of IgG2 levels was estimated to be 38% and highly significant (P = 0.0006), demonstrating a substantial genetic basis. Bi-trait variance component analyses of IgG2 and quantitative measures of AgP indicate that different genes appear to control IgG2 levels and disease susceptibility.

Phosphorylcholine-dependent cross-reactivity between dental plaque bacteria and oxidized low-density lipoproteins.

Antibodies reactive with phosphorylcholine (PC) are ubiquitous in human sera, but the antigens stimulating their production and their function are not clear. Previous studies have shown that a significant proportion of dental plaque bacteria contain PC as determined by reactivity with PC-specific mouse myeloma proteins and monoclonal antibodies. Additionally, serum antibody concentrations of immunoglobulin (IgG) G anti-PC are higher in sera of individuals who have experienced periodontal attachment loss than those who are periodontally healthy. These data implicate the oral microflora as a source of antigen-stimulating anti-PC responses. Recent data also indicate that antibodies with specificity for PC are elevated in ApoE-deficient mice, a model for studies of athersclerosis, and that such antibodies bound oxidized low-density lipoproteins (LDL) (oxLDL) in atherosclerotic plaques. These data prompted the hypothesis that human anti-PC could bind to both oral bacteria and human oxLDL, and that these antigens are cross-reactive. We therefore examined the ability of human anti-PC to bind to PC-bearing strains of oral bacteria using enzyme-linked immunosorbent inhibition assays and by assessment of direct binding of affinity-purified human anti-PC to PC-bearing Actinobacillus actinomycetemcomitans. Our results indicated that PC-bearing strains of Streptococcus oralis, Streptococcus sanguis, Haemophilus aphrophilus, Actinomyces naeslundii, Fusobacterium nucleatum, and A. actinomycetemcomitans, as well as a strain of Streptococcus pneumoniae, absorbed up to 80% of anti-PC IgG antibody from human sera. Furthermore, purified anti-PC bound to a PC-bearing strain of A. actinomycetemcomitans but only poorly to a PC-negative strain. OxLDL also absorbed anti-PC from human sera, and oxLDL but not LDL reacted with up to 80% of the anti-PC in human sera. Furthermore, purified anti-PC bound directly to oxLDL but not to LDL. The data indicate that PC-containing antigens on a variety of common oral bacteria are cross-reactive with neoantigens expressed in oxLDL. We propose that PC-bearing dental plaque microorganisms may induce an antibody response to PC that could influence the inflammatory response associated with atherosclerosis.

Evidence of a substantial genetic basis for risk of adult periodontitis.

BACKGROUND: A few previous studies have suggested that risk for adult periodontitis (AP) has a genetic (heritable) component. We estimated genetic and environmental variances and heritability for gingivitis and adult periodontitis using data from twins reared together. METHODS: One hundred seventeen (117) pairs of adult twins (64 monozygotic [MZ] and 53 dizygotic [DZ] pairs) were recruited. Probing depth (PD), attachment loss (AL), plaque, and gingivitis (GI) were assessed on all teeth by two examiners. Measurements were averaged over all sites, teeth, and examiners. Extent of disease in subjects was defined at four thresholds: the percentage of teeth with AL > or = 2, AL > or = 3, PD > or = 4, or PD > or = 5 mm. Genetic and environmental variances and heritability were estimated using path models with maximum likelihood estimation techniques. RESULTS: MZ twins were more similar than DZ twins for all clinical measures. Statistically significant genetic variance was found for both the severity and extent of disease. AP was estimated to have approximately 50% heritability, which was unaltered following adjustments for behavioral variables including smoking. In contrast, while MZ twins were also more similar than DZ twins for gingivitis scores, there was no evidence of heritability for gingivitis after behavioral covariates such as utilization of dental care and smoking were incorporated into the analyses. CONCLUSIONS: These results confirm previous studies and indicate that approximately half of the variance in disease in the population is attributed to genetic variance. The basis for the heritability of periodontitis appears to be biological and not behavioral in nature.

Linkage disequilibrium of interleukin-1 genetic polymorphisms with early-onset periodontitis.

BACKGROUND: Genetic polymorphisms at interleukin (IL)-1alpha and IL-1beta were recently suggested to be associated with severity of adult periodontitis. We evaluated whether these polymorphisms might also be associated with early-onset periodontitis (EOP) in 28 African American families and 7 Caucasian American families with 2 or more affected members. METHODS: Genomic DNA from peripheral blood was amplified, followed by restriction endonuclease digestion and acrylamide gel electrophoresis to distinguish alleles of different fragment sizes. Genetic epidemiological methods suitable for family data were used that are robust to false-positive findings due to mismatching of cases and controls or mixed subpopulations of different ethnic or geographic origin. The 2 major EOP subtypes, localized juvenile periodontitis (LJP), and generalized early-onset periodontitis (G-EOP, encompassing rapidly progressive periodontitis and generalized juvenile periodontitis), were analyzed both separately and together. RESULTS: We obtained highly significant evidence of linkage disequilibrium for both African American and Caucasian G-EOP subjects. A similar trend was noted for LJP. The IL- alleles associated with high risk of EOP had been suggested previously to be correlated with low risk for severe adult periodontitis. Disequilibrium with G-EOP was equally strong for smoking and non-smoking subjects. IL-1alpha and IL-1beta polymorphisms were in strong disequilibrium with each other in Caucasians, but not in African Americans. Haplotype analyses evaluating both polymorphisms simultaneously indicated that the IL-1beta variant is likely to be most important for EOP risk. Sibpair linkage analyses, by contrast, provided only marginal support for a gene of very major effect on EOP risk attributable to these IL-1 polymorphisms. CONCLUSIONS: Recent theoretical analyses indicate that our findings are most consistent with an interpretation of EOP as a complex, oligogenic disorder, with IL-1 genetic variation contributing an important but not exclusive influence on disease risk.

Genetic segregation analyses of serum IgG2 levels.

Summary : The aim of this study was to determine whether there was evidence for a genetic component in the immune response as measured by IgG2 levels. The study was motivated by our studies of early-onset periodontitis (EOP), a group of disorders characterized by rapid destruction of the supporting tissues of the teeth in otherwise healthy individuals. EOP has two subforms, localized juvenile periodontitis (LJP) and a generalized form (G-EOP). IgG2 levels are elevated in LJP but not G-EOP individuals; and African-American IgG2 levels are higher than Caucasian levels regardless of EOP status. IgG2 levels were determined in 123 EOP families and in 508 unrelated non-EOP control individuals. Segregation analysis under the regressive model approach of Bonney was used to analyze IgG2 levels for evidence of major locus segregation. After adjusting for LJP status, race, sex, and age, the best fitting model was an autosomal codominant major locus model (accounting for approximately 62% of the variance in IgG2), plus residual parent/offspring and spousal correlations. Smoking and GM23 are also known to affect IgG2 levels. If additional adjustments are made for smoking and GM23, the best-fitting model is still a codominant major locus but with no significant residual correlations.

Longitudinal assessment of early onset periodontitis.

The purpose of this study was to determine the clinical course of early onset periodontitis and to investigate factors which may influence its clinical course. For the past 15 years we have been conducting a study of families with early onset periodontitis, and have examined 142 localized juvenile periodontitis and 185 severe generalized early onset periodontitis patients. In order to study the clinical course of early onset periodontitis we recalled our subject population to determine their periodontal status. Forty (40) patients with localized early onset periodontitis (LJP) and 48 with generalized early onset periodontitis (SP) were re-examined. The time since the most recent visit for LJP patients was approximately 3 years and for SP patients almost 4 years. LJP patients who received periodontal therapy on the average gained periodontal attachment. In contrast, LJP patients who did not receive therapy lost periodontal attachment. SP patients lost periodontal attachment regardless of whether or not they had periodontal therapy. SP patients also lost an average of one tooth during the approximately 4 years of observation. LJP patients lost very few teeth with only 4 teeth being lost in 40 patients. The results of this study suggest that localized juvenile periodontitis is a stable disease in most individuals. In contrast, patients with severe generalized early onset periodontitis continued to lose both periodontal attachment and teeth.

Evidence for autosomal dominant inheritance and race-specific heterogeneity in early-onset periodontitis.

Early-onset periodontitis (EOP) refers to a group of severe periodontal diseases with age of onset near puberty that are characterized by rapid destruction of the tissues supporting the teeth in otherwise healthy individuals. Mixed model segregation analyses of 100 families, ascertained through 104 probands with EOP, were carried out to test major locus and multifactorial hypotheses for the etiology of EOP. Heterogeneity tests were used to compare the parameter estimates and conclusions obtained in Black families from those from non-Black families. The data in these families confirmed that the often-reported female preponderance of EOP appears to be an ascertainment bias. The segregation analysis results were consistent with an autosomal major locus being sufficient to explain the family patterns of EOP in the entire dataset, and also in both the Black and non-Black subsets. A dominant mode of transmission was most likely, with penetrance of about 70%. Although the etiologic conclusions were the same for Black and non-Black families, there was significant heterogeneity in parameter estimates. In particular the Black allele frequency was 0.016 versus the non-Black frequency of 0.001.

Investigation of the influences of puberty, genetics, and environment on the composition of subgingival periodontal floras.

The classical twin model was utilized in this study in an attempt to determine the importance of host genetics to the composition of the subgingival flora. Simultaneously, the effect of puberty on the flora composition was assessed. The compositions of the floras were significantly different at ages 11 and 14 in the same people, indicating that transition to an adult flora composition may be initiated during puberty. However, the numbers of subjects who had prepubertal and postpubertal testosterone levels in this study were too small to demonstrate significant differences based solely on testosterone level (P = 0.053 and 0.11 for tests of unrelated members, i.e., all twins "a," the first twin of each pair, and all twins "b," the second twin of each pair). Sixteen unrelated 11-year-old subjects had prepubertal levels of less than 30 ng of testosterone per dl of serum, and only six of these unrelated subjects had levels above 300 ng/dl by age 14. Of their twin siblings, who formed the second group of unrelated individuals, 15 had prepubertal levels and only 5 reached postpubertal levels. Unpaired t tests indicated that Veillonella atypica, Prevotella denticola, and Prevotella melaninogenica were among the species that contributed most to changes in flora composition during puberty. The compositions of subgingival floras of 11-year-old monozygous and dizygous male twins were significantly more similar than those of unrelated subjects in the study (P = 0.004 and 0.009, respectively). At 12.5 years of age, the floras of monozygous twins remained more similar than those of unrelated subjects (P = 0.001), but the dizygous-twin floras were not significantly more similar than those of unrelated people. This difference corresponded with moderate and varied testosterone levels within dizygous-twin pairs at age 12.5. By age 14 both monozygous and dizygous twins again had floras with compositions more similar than those of unrelated people (P = 0.008 and 0.002, respectively). Estimates of the genetic contributions to the increased similarity of the floras of twins as compared with floras of unrelated people indicated that the concentrations of several species in the flora may be influenced by host genetic factors. The prevalence of certain other species appeared to be controlled primarily by environment.

The influence of race and gender on periodontal microflora.

Previous studies have demonstrated that demographic characteristics of subject populations influence both the incidence of periodontal diseases and various aspects of host responses to periodontal bacteria. In this study we analyzed the components of the subgingival microflora from individuals with adult periodontitis, early onset periodontitis, gingivitis, and periodontal health as a function of gender and race (black and white). Clinical categories were analyzed individually so that there were no differences in the clinical characteristics of the sampled sites. No significant differences were noted in the subgingival microflora between males and females. When either the first two bacterial samples from each subject or all bacterial samples taken from each subject were included in the analysis, it was found that Porphyromonas gingivalis was more significantly associated with black subjects in the adult periodontitis group. When all samples were considered in the analysis, it was found that Peptostreptococcus anaerobius was associated with black subjects in the adult periodontitis group, while Fusobacterium nucleatum was associated with white subjects in both the adult periodontitis and early onset periodontitis groups. Thus a limited number of important bacterial components of the subgingival microflora are influenced by the race and diagnosis of the subject group.

Periodontal microflora of HIV positive subjects with gingivitis or adult periodontitis.

The subgingival microflora of 39 HIV+ subjects with gingivitis or adult periodontitis was cultured quantitatively anaerobically for bacteria, spirochetes, and mycoplasma and aerobically for yeasts. Isolates were characterized by conventional biochemical tests, polyacrylamide gel electrophoresis of soluble proteins, cellular fatty acid profiles, immunofluorescence, and immunodiffusion. In general, the same types of bacteria were isolated from the subgingival crevice of HIV+ subjects as we previously had isolated from the subgingival crevice of non-HIV subjects. A statistically significant difference was found between the composition of the flora of HIV+ subjects with adult periodontitis (AP) and concurrent studies of a non-HIV+ AP population. Mycoplasma salivarium was significantly elevated in the HIV+ subjects examined. Yeasts were isolated from only 10% of the samples and from 13% of the HIV-positive subjects at 0.05 to 0.0002% of the total cultivable count when present.

Periodontal health in 200 HIV-positive patients.

Two hundred HIV-positive subjects were surveyed to determine their periodontal health status. Particular attention was given to the occurrence of a severe and rapidly progressing form of periodontal disease designated "HIV-associated periodontitis", which has been reported as being unique to AIDS patients. Among the subjects comprising the cohort, 85 subjects had good gingival health, 59 subjects exhibited gingivitis, 49 cases of adult periodontitis were observed, 5 subjects presented with advance adult periodontitis, and 2 cases of necrotizing ulcerative periodontitis (NUP) were found within the group. The periodontitis of the patients in this survey did not have unique or pathognomonic characteristics which could set their periodontal disease apart from the periodontal disease seen in HIV negative population.

The microflora of periodontal sites showing active destructive progression.

20 adult periodontitis (AP) subjects were examined every 2 to 4 months and microbiological samples were collected and cultured when 2 mm or more loss of attachment (active sites) was detected by 2 examiners. Similar sites in which no progressive destruction was observed (control sites) also were sampled in the same subjects. By lambda-analysis, there was no statistically significant difference in floras of active (42 sites from 12 subjects) and control (36 sites from 12 subjects) sites or between the floras of the active and control sites and of 63 samples from 22 AP subjects that were examined previously in a cross-sectional study. By paired t test, no microbial species had a significantly greater association with active than with control sites. The only species that were detected in one or more samples from all subjects with active sites were Wolinella recta, Fusobacterium nucleatum, and Peptostreptococcus micros. Porphyromonas gingivalis and 9 other taxa were isolated from one-half or more of the persons with active sites. The composition of microbiological floras of all periodontitis samples was statistically significantly different from that of subjects with healthy gingiva. The composition of microfloras of sites in subjects with naturally-occurring gingivitis was intermediate between that of subjects with healthy gingiva and that of active and control sites in AP subjects.

Actinobacillus actinomycetemcomitans in families afflicted with periodontitis.

The purpose of this study was to determine the prevalence of Actinobacillus actinomycetemcomitans (Aa) in individuals from families where at least one individual has an early onset form of periodontitis. Twenty-three families with 73 subjects were evaluated in this study. Forty-seven early onset periodontitis subjects outside the 23 families were also studied. Prevalence of detection of Aa in family members ranged from 49% to 66% among groups constituted by clinical findings indicative of no loss of attachment, adult periodontitis, generalized severe juvenile periodontitis, or localized juvenile periodontitis. Whether the data were analyzed by subject or by site, no statistical differences could be found in prevalence (proportion of positive samples) among those clinical groups. The only significant difference was that localized juvenile periodontitis subjects had higher concentrations of Aa in their Aa-positive sites than did the other clinical groups. The prevalence of Aa-positive sites in subjects without attachment loss, but who are members of families in which early onset periodontitis is represented, was much higher than in other reports where periodontally healthy subjects were not related to early onset periodontitis cases. This suggests that Aa may be transmitted among members of families in which one or more members has an early onset form of periodontitis.

Reliability of attachment loss measurements in a longitudinal clinical trial.

In order to appropriately carry out a longitudinal assessment of periodontal attachment loss in individuals with untreated periodontitis, reliable criteria for determining "real" changes in attachment level (AL) are required. In the present study, 25 subjects were to be examined every 2 months for up to 2 years to determine changes in AL and to relate clinical and laboratory criteria to such changes. Trained examiners for the study underwent calibration trials to determine inter-examiner and intra-examiner reliability both before the study and at intervals during the study. It was found that AL measurements were in agreement within 2 mm more than 95% of the time. The calibration trials provided an estimate of the error in attachment loss measurements, since no "real" attachment loss had occurred. From estimates of measurement error, the probability of false positive changes were determined. It was found that acceptable false positive rates (less than 5%) could be achieved if 2 examiners each detected 3 mm change at a given site or if 2 examiners each detected 2 mm change at a site and verified that this change persisted at a subsequent examination. The results of the longitudinal trial were then compared to the probability estimates calculated from the calibration trials. It was found that probabilities of AL changes detected during the longitudinal trial for less stringent conditions than described above (e.g., single examiner, 2 examiners unconfirmed) were similar to to previously estimated false positive rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum antibodies to periodontal bacteria.

The purpose of this study was to determine how serum antibodies reactive with periodontitis-associated bacteria with relates to the diagnosis of periodontitis subjects. Study groups included localized juvenile periodontitis (LJP) subjects, severe periodontitis (SP) subjects, chronic adult periodontitis (AP) subjects, and age matched controls. Twenty-two bacterial strains, representing 18 different species most commonly found in early onset periodontitis were evaluated using serum from LJP, SP, and age matched controls. Serum IgG reactive with these organisms was determined using a radioimmunoassay (RIA). Serum antibody reactive with 13 bacterial strains differed significantly (P less than 0.01) between the three clinical groups. Discriminate analysis revealed that antibodies reactive with 5 bacterial strains of the 13 were able to identify the clinical group to which subjects belonged 79% of the time with control subjects being correctly identified 100% of the time, LJP subjects 78% of the time, and SP subjects 60% of the time. These strains included two strains of Actinobacillus actinomycetemcomitans (Y4 and N27), Fusobacterium nucleatum (E1D1), Eubacterium brachy, and Bacteroides gingivalis. The low classification rate of SP subjects suggested heterogeneity. The SP group could be divided into three subgroups using the serological data. One subgroup, with "super" severe attachment loss, generally lacked antibody reactive with these five organisms, another subgroup was serologically similar to LJP subjects, while the third subgroup had antibodies to additional organisms. This suggests that some SP subjects may represent a more advanced form of LJP. Comparison of antibody reactivity of AP subjects with age matched controls to 23 bacterial types revealed that mean serum antibody reactivity to only Bacteroides gingivalis was higher in AP subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriology of human gingivitis.

The subgingival bacterial floras of naturally occurring gingivitis in adults and children were characterized and compared with the floras of other periodontal conditions previously studied. The composition of the gingivitis floras was found to be distinct from that of floras associated with health or with moderate, severe, or juvenile periodontitis. There were no major differences between the floras of naturally-occurring gingivitis and the floras of the human experimental gingivitis model. Data indicated that the flora of healthy sites within a mouth is influenced by the number of inflamed sites, which argues against independence of sites bacteriologically. Proportions of ten bacterial species increased in both gingivitis and periodontitis, as compared with health, in both adults and children. These species were found in both affected and unaffected sites of people with gingivitis. The numbers of five other cultivable species and the "large treponeme", which was not cultivated, increased in gingivitis and periodontitis of adults only. Significant differences in non-spirochetal floras between children and adults were not found, although they were in the experimental gingivitis model studied previously. Cultivable spirochetes did differ between children and adults. Children had fewer samples positive for spirochetes, and children's positive samples contained greater proportions of T. socranskii subsp. paredis. Some species that predominate in periodontitis, but which are absent from healthy gingivae, were found as a small percentage of the flora in gingivitis. This suggests that increased serum and blood in the gingival crevice encourage species that relate to periodontitis.