Comparative antibody titers to Actinobacillus actinomycetemcomitans in juvenile periodontitis, chronic periodontitis and periodontally healthy subjects

Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans isolated from a population of periodontitis patients in Spain

OBJECTIVE

There is no study characterizing the variability of Aggregatibacter actinomycetemcomitans isolates in periodontitis patients in Spain. It is therefore the aim of this investigation to study the serotype distribution of A. actinomycetemcomitans strains isolated from periodontitis patients in Spain. The polymorphism of the genes that codifies the leukotoxin and the operon of the cytolethal-distending toxin (cdt) will also be investigated.

DESIGN

From a total of 701 patients samples, 40 A. actinomycetemcomitans-positive periodontitis patients were included in the study (mean age 45.3, 62.5% females) and their clinical periodontal status was assessed. On average, 1-3 isolates from each patient were sub-cultured and characterized by PCR.

RESULTS

Using culture the prevalence of A. actinomycetemcomitans was 5.7%. The most frequent serotype was "b", being 30 patients infected by a unique serotype, while 7 patients showed co-colonization, mostly with serotypes "a" and "b". From the 79 pure isolates obtained, 24 were from serotype "a", 30 from serotype "b", 12 from serotype "c" and 4 from serotype "d". Further characterization of these samples showed that none of these 79 isolates demonstrated the 530-bp deletion in the leukotoxin's promoter region that characterizes the JP2 strain. Conversely 65.8% of the isolates were cdt+.

CONCLUSIONS

The most common serotypes were "a" and "b", being serotype "b" the most prevalent in mono-colonization, while serotypes "e" and "f" were not detected. In the majority of samples, operon that codifies the cdt (65.8%) and the genes responsible for the codification of leukotoxin (100%) were found. None of the isolates were JP2 strains.

Optimization of quantitative polymerase chain reactions for detection and quantification of eight periodontal bacterial pathogens

Background

The aim of this study was to optimize quantitative (real-time) polymerase chain reaction (qPCR) assays for 8 major periodontal pathogens, i.e. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Parvimonas micros, Porphyromonas gingivalis, Prevotella intermedia, Tanerella forsythia and Treponema denticola, and of the caries pathogen Streptococcus mutans.

Results

Eighteen different primer pairs were analyzed in silico regarding specificity (using BLAST analysis) and the presence of secondary structures at primer binding sites (using mFOLD). The most specific and efficiently binding primer pairs, according to these analyses, were selected for qPCR-analysis to determine amplification efficiency, limit of quantification and intra-run reproducibility. For the selected primer pairs, one for each species, the specificity was confirmed by assessing amplification of DNA extracts from isolates of closely related species. For these primer pairs, the intercycler portability was evaluated on 3 different thermal cyclers (the Applied Biosystems 7300, the Bio-Rad iQ5 and the Roche Light Cycler 480). For all assays on the different cyclers, a good correlation of the standard series was obtained (i.e. r² ≥ 0.98), but quantification limits varied among cyclers. The overall best quantification limit was obtained by using a 2 μl sample in a final volume of 10 μl on the Light Cycler 480.

Conclusions

In conclusion, the proposed assays allow to quantify the bacterial loads of S. mutans, 6 periodontal pathogenic species and the genus Fusobacterium.This can be of use in assessing periodontal risk, determination of the optimal periodontal therapy and evaluation of this treatment.

Infection patterns in chronic and aggressive periodontitis

BACKGROUND

We revisited the postulate that localized aggressive periodontitis (LAP) patients have robust serum antibody (ab) responses to periodontal pathogens while patients with generalized aggressive periodontitis (GAP) show weak responses. We also studied ab responses in localized chronic (LCP) and generalized chronic periodontitis (GCP).

METHODS

Fifty-seven patients (14-74 years, 25% male, 70% Hispanic, 26% African American) were studied (15 LAP, 19 GAP, 11 LCP, 12 GCP patients). Three plaque samples/subject were analysed with respect to 15 species, and serum immunoglobulin G (IgG) responses to the same bacteria were determined. Ab responses were expressed as log-transformed titres, and "infection ratios", i.e., log-transformed ratios of ab titre over the subject-based mean bacterial load for the homologous species.

RESULTS

The results failed to corroborate the postulate that LAG patients have robust responses to infecting agents while GAP subjects exhibit weak responses. This held true for ab to "red complex", "orange complex", and health-associated species, and for both titres and infection ratios. Similarly, no differences were found between ab titres or infection ratios in chronic and aggressive periodontitis, or their extent-based subdivisions.

CONCLUSIONS

A distinction between the two principal categories of the current periodontitis classification cannot be established by the study of infection patterns.

Relationship ofActinobacillus actinomycetemcomitansSerotype b to Aggressive Periodontitis: Frequency in Pure Cultured Isolates

BACKGROUND

To our knowledge, the association of the five serotypes of Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) to the new diagnostic classification scheme defined by the American Academy of Periodontology in 1999 has not yet been described. The goal of this study was to characterize the frequencies of the five serotypes of A. actinomycetemcomitans in A. actinomycetemcomitans isolates from various forms of periodontitis using both old and new diagnostic classifications and to determine the relationships between serotype and age and clinical diagnosis.

METHODS

A total of 345 A. actinomycetemcomitans isolates from 115 A. actinomycetemcomitans culture-positive subjects (mean age 38.0 +/- 18.3 years, 59% female) were collected. Based on the new classifications, 33 subjects had aggressive periodontitis and 82 chronic periodontitis. According to old classifications, there were six prepubertal periodontitis (PPP), 12 localized juvenile periodontitis (LJP), 15 post-localized juvenile periodontitis (PLJP), 28 refractory periodontitis (Ref-P), and 54 adult periodontitis (AP) cases. Serotypes of A. actinomycetemcomitans were determined by an indirect immunofluorescence assay using serotype-specific polyclonal antisera to A. actinomycetemcomitans strains ATCC 29523, ATCC 43728, ATCC 33384, IDH 781 and IDH 1705 (serotype a, b, c, d, and e, respectively). Proportions of serotype b were examined between different diagnostic and age groups with a Z-test for proportions.

RESULTS

Most subjects (n = 100, 86.96%) were infected with a single serotype (22 serotype a, 44 serotype b, 30 serotype c, 1 serotype d, and 3 serotype e). There were 11 subjects (9.57%) with two serotypes and two subjects (1.74%) with 3 serotypes. Two individuals had isolates lacking any detectable serotype antigen. Serotype b was the predominant serotype in children under 18 years of age and young adults between 19 to 35 years, although serotype b status was not significantly associated with age. Serotypes d and e were not found in patients under 35 years old. In 62 adult patients, one subject had serotype d and three had serotype e. Serotype b was the most common serotype in aggressive periodontitis (60.61%). The proportion of cases with serotype b was significantly higher in aggressive periodontitis compared to chronic periodontitis (P = 0.031). Other serotypes were not significantly associated with new diagnostic categories. Serotypes d and e were not detected in aggressive periodontitis.

CONCLUSION

The results of this study show that proportions of serotype b of A. actinomycetemcomitans are significantly greater in culture-positive patients with aggressive periodontitis than those with chronic periodontitis.

Simple and rapid detection of serum antibody to periodontopathic bacteria by dot blotting

The aim of this study was to detect the specific immunoglobulin G antibodies against periodontopathic bacteria by dot blotting. In the procedure used, bacterial preparations were blotted on a nitrocellulose membrane. After blocking the nonspecific binding sites, the diluted serum was blotted onto the preparations. The membrane was immersed in secondary antibodies and then in substrate buffer. The colored blots were then evaluated. To test the reliability of this procedure, 20 serum samples were examined for antibody: ten for anti-Porphyromonas gingivalis antibody, and the other ten for anti-Actinobacillus actinomycetemcomitans antibody. Five samples out of each set of ten had previously been confirmed as having high enzyme-linked immunosorbant assay (ELISA) titers to the antigen, while the other five had been confirmed as having average titer levels. Both whole-cell sonic extracts and fimbriae of P. gingivalis were used as antigens in the dot blotting, in order to compare their use as antigens in assays of the patients' sera. ELISA was also used to measure anti-P. gingivalis antibody titers. For the measurement of IgG antibodies against A. actinomycetemcomitans, formalin-killed whole cells were used. Fifty serum samples were examined for IgG antibodies against A. actinomycetemcomitans by dot blotting and ELISA. With both antigens, after 4 h, coloration of blots was more clearly visible for the high-titer sera than for the average-titer sera. The intensity of coloration of the blots for P. gingivalis and A. actinomycetemcomitans showed correlation with the ELISA titers. A particularly significant correlation was shown when P. gingivalis fimbriae were used as antigen. These results suggest that this dot blot method is a simple and rapid means of detection of serum antibodies, and that it shows promise as a chair-side assay method.

Serum IgG antibody response to periodontal pathogens in minority populations: relationship to periodontal disease status and progression

Differences in periodontal disease prevalence, severity, subgingival microflora and host immune response have been reported for various ethnic/racial groups, which implies that risk factors for destructive periodontal disease progression may also vary in these populations. As it is possible that these differences may be due to confounding variables other than ethnicity/race, we have measured serum IgG antibody response to six periodontal pathogens, and compared these data with microbiological, clinical and demographic parameters in three urban minority populations. The study population consisted of 23 Asiatic, 48 African-American and 37 Hispanic subjects, who were resident in the greater New York region. Clinical indices that were recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration and supragingival plaque. Attachment level measurements were taken twice at each visit, and the difference between the means of pairs of measurements taken at baseline and two months later was used to determine disease progression. Subgingival microbiological species were identified and enumerated using DNA-DNA checkerboard hybridization. Serum IgG antibody levels to Actinobacillus actinomycetemcomitans serotyopes a and b, Bacteroides forsythus, Campylobacter rectus, Porphyromonas gingivalis and Prevotella intermedia were measured by enzyme-linked immunosorbant assay (ELISA). Mean serum IgG antibody to P. gingivalis was found to be higher in the African-American group, while IgG antibody to B. forsythus was lower in the Hispanic group. However, the African-American group also had greater mean probing depth, attachment loss, number of missing teeth and numbers of individuals within the unskilled occupational group. When the data were analyzed by occupational status, mean serum IgG antibody to P. gingivalis increased from professional to skilled to unskilled groups. For the entire study population, prior disease and subsequent attachment loss were associated with elevated serum IgG antibody to P. gingivalis. Increasing pocket depth, attachment level, gingival erythema and age were also positively correlated with serum IgG antibody to P. gingivalis, but not with serum IgG antibody to the other five subgingival species. No correlation was found between whole-mouth bacterial levels and homologous serum IgG antibody levels. These results suggest that elevated serum IgG antibody to P. gingivalis reflects destructive periodontal disease status, and may be considered a risk factor for disease progression in these ethnic/racial populations. In addition, although differences in serum IgG antibody profiles to subgingival species were found among the three ethnic/racial groups, environmental and socioeconomic variables may have a greater influence on serum IgG antibody levels in these populations.

W, ITANO EN. Anticorpos antileucotoxina contra Actinobacillus actinomycetemcomitans em amostras de soro e saliva de pacientes com periodontite juvenil localizada

A leucotoxina de Actinobacillus actinomycetemcomitans é considerada seu principal fator de virulência com potencial de causar agressão às defesas do hospedeiro. No presente trabalho, foram analisados os níveis séricos e salivares de anticorpos antileucotoxina de A. actinomycetemcomitans em soros e salivas de pacientes com periodontite juvenil localizada (PJL) e controles saudáveis. Adicionalmente, foi realizada a análise de complexo imune (CI) nas amostras de saliva. Foram utilizados os métodos ELISA clássico com a leucotoxina obtida por gel filtração em Sephadex G-200 e ELISA de captura utilizando IgG de coelho anti-A. actinomycetemcomitans FDC Y4 leucotóxico adsorvido com uma cepa da mesma espécie, porém, não leucotóxica. Os resultados obtidos demonstraram níveis séricos de IgG significativamente mais elevados em pacientes com PJL em relação aos controles sadios, tanto por ELISA clássico como por ELISA de captura (p < 0,05). No entanto, não foram observadas diferenças entre os níveis de IgG, IgA-S e CI nas salivas dos indivíduos examinados. Estes resultados sugerem que, embora A. actinomycetemcomitans apresente vários fatores de virulência que afetam a resposta imune do hospedeiro, ocorre resposta imune à leucotoxina nos pacientes com PJL. Esse aumento de IgG na circulação sangüínea pode contribuir na defesa do hospedeiro, limitando a lesão nas regiões periodontais amplamente colonizadas por A. actinomycetemcomitans.

Antigenic specificity of gingival crevicular fluid antibody to Actinobacillus actinomycetemcomitans

Elevated antibody levels to periodontopathogens in GCF have been identified and used as support for local antibody synthesis in periodontitis. This study examined both cross-sectional and longitudinal GCF samples for the antigenic specificity of antibody in the fluid. GCF samples were collected from each tooth of 27 periodontitis patients infected with A. actinomycetemcomitans. Levels of IgG antibody in the GCF were assessed by means of an ELISA and compared with serum for determination of local elevations. A proportion of those GCF samples that exhibited significantly elevated antibody were examined by Western immunoblotting to outer membrane antigens from A. actinomycetemcomitans. Homologous sera were also examined for comparison of antibody specificities. Of the sites with elevated IgG antibody, 87% were colonized by A. actinomycetemcomitans; however, 46% of sites with A. actinomycetemcomitans infection did not have elevated antibody. Cross-sectional studies identified a 78 to 100% agreement between the antibody specificities in GCF and those in serum. Additionally, patterns of antibody reactivity in both GCF and serum in the subjects were often very distinctive. Longitudinal alterations in GCF antibody were examined in 15 patients through a monitoring interval of up to 2 years and showed a general conservation of specificities. However, 7/15 patients exhibited a definite acquisition of different antibody specificities during the monitoring. These results describe a relationship between elevated local antibody and A. actinomycetemcomitans infection. Furthermore, the antibody specificities in serum appear to reflect generally the local response to this pathogen.

Early-onset periodontitis

In 1993, the 1st European Workshop on Periodontology explicitly recognized that there was insufficient knowledge to differentiate truly different forms of periodontal disease from differences in the presentation/severity of the same disease. In spite of recent progress in our understanding of periodontal diseases, the issue is far from having been resolved. Classification of periodontal diseases, therefore, remains based upon the definition of specific clinical syndromes. Early-onset periodontitis (EOP) is one such syndrome and comprises a group of pathological conditions leading to loss of periodontal tissues early in life. The notion that classifies periodontitis syndromes as "early-onset" or "adult" is primarily epidemiological in nature and is based on the observation that periodontitis is rather infrequent in children and young adults. Nevertheless, considerable epidemiological evidence indicates that periodontitis does affect children and young adults to a level of severity that may lead to premature exfoliation of primary and/or permanent teeth. Clinical presentation of periodontitis early in the life of an individual is thought to indicate that the etiologic agents have been able to cause considerable tissue damage over a relatively short period of time. It also implies either infection with highly virulent bacteria and/or a highly susceptible subject. The purpose of this review is to discuss the criteria generally utilized to classify EOP, provide the rationale to designate EOP as a distinct disease entity, and to review the evidence justifying a subclassification into particular subgroups of EOP.

Periodontal Findings and Systemic Antibody Responses to Oral Microorganisms in Behçet's Disease

BACKGROUND

Behçet's disease is a multisystem disorder of unknown etiology, affecting predominantly the oral mucosa, skin, and eyes. Recurrent and painful episodes of oral ulcerations interfere with regular oral hygiene leading to rapid bacterial plaque accumulation. The aims of this study were to evaluate the periodontal status of patients with Behçet's disease and determine serum antibody responses to selected oral microorganisms, including major periodontopathogens in these patients.

METHODS

Thirty-three patients with Behçet's disease and 15 healthy subjects were included in the study. Plaque, sulcular bleeding, periodontal index scores, probing depths, and total number of teeth were recorded. Serum IgG antibody levels to a panel of 13 oral microorganisms were determined.

RESULTS

Significantly higher values for each of the clinical measures were observed in patients with Behçet's disease compared to healthy subjects (P <0.0001). Antibody levels to selected members of plaque, including Actinomyces viscosus, Streptococcus mutans, Streptococcus sanguis, Streptococcus oralis, Eikenella corrodens, Campylobacter rectus, and Prevotella intermedia were significantly lower in patients with Behçet's disease than in controls (P <0.001-0.05). In contrast, these patients exhibited significantly elevated antibody levels to Actinobacillus actinomycetemcomitans Y4 compared to controls (P <0.01).

CONCLUSIONS

Our data indicate that the patients with Behçet's disease generally exhibit clinical findings of established periodontal disease. Decreased antibody responses to early colonizers of both supra- and subgingival plaque were observed along with the elevation in antibody levels to A. actinomycetemcomitans. These results suggest that the bacterial plaque ecology and/or immune responses to these microorganisms may be affected in Behçet's disease which could lead to changes in the expression of periodontal disease.

Oral and systemic immunoglobulin G-subclass antibodies to Actinobacillus actinomycetemcomitans leukotoxin

Salivary, gingival crevicular fluid and serum-specific immunoglobulin G (IgG)-subclass antibodies to Actinobacillus actinomycetemcomitans leuktoxin were quantified by enzyme-linked immunosorbent assay. Samples were taken from six patients with periodontal pockets > or = 5 mm, harboring A. actinomycetemcomitans in subgingival plaque and from six healthy, sex- and age-matched controls, who did not harbor A. actinomycetemcomitans. In individuals suffering from periodontitis, the median values of specific IgG1- and IgG2-subclass antibodies in saliva, gingival crevicular fluid and serum were, respectively IgG1 147 ng/ml, 5226 ng/ml and 7318 ng/ml and IgG2 4.8 ng/ml, 934 ng/ml and 860 ng/ml. In the patients, specific IgG3 antibodies were detected in one out of six individuals in saliva, in two individuals in gingival crevicular fluid and in five out of six patients in serum with a median value of 561 ng/ml. The median values of specific IgG4 antibodies in saliva, gingival crevicular fluid and serum were below detectable levels. The median values of the total IgG subclasses in saliva and serum were 14622 ng/ml and 10.3 g/l respectively. Individuals with periodontitis had, compared with controls, a higher ratio of specific IgG1 antibodies to total IgG1 in saliva (P < 0.05) and in serum (P < 0.05) and a higher ratio of specific IgG antibodies to total IgG in saliva (P < 0.05) and in serum (P < 0.01). The results show an elevation of both oral and systemic specific antibodies to A. actinomycetemcomitans leukotoxin.

Evidence-based care in orthodontics and periodontics: a review of the literature

BACKGROUND

In this article, the author reviews the evidence-based literature in the fields of periodontics and orthodontics to clarify the relationship between orthodontic tooth movement and various types of common periodontal disorders.

TYPES OF STUDIES REVIEWED

The first section is a review of the literature on common periodontal disorders. The second is a review of evidence-based studies in the combined fields of orthodontics and periodontics, with a focus on orthodontic treatment possibilities, limitations and risks inherent in patients with periodontal disorders, particularly active periodontal disease.

RESULTS

The literature on orthodontic tooth movement as it relates to periodontal disease shows that proper orthodontic treatment in patients with excellent oral hygiene and the absence of significant periodontal disorders should not pose any significant periodontal risk. In the presence of poor oral hygiene, however, and under circumstances of certain types of periodontal disorders, fixed orthodontic appliances and tooth movement can contribute to significant deleterious periodontal consequences.

CLINICAL IMPLICATIONS

This review provides a clear understanding of what is known about orthodontic treatment possibilities, limitations and inherent risks in patients who may have certain types of periodontal disorders. It also underscores the importance of teamwork among the restorative dentist, periodontist and orthodontist when planning treatment for these patients. The author also offers a specific patient management protocol for this interdisciplinary dental team to follow.

Periodontitis-associated marker bacteria in an urban North American patient population: application of a commercial immunoassay

We used an immunoassay to demonstrate marker organisms (Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans) in 3 private practice populations (F-ME periodontist, 55 patients; MHM periodontist, 179 patients; and EWM general dentist, 19 patients). Occurrence of the marker organisms involves the whole oral environment, not just individual sites, as shown by close correlation between presence of the marker organisms in 2 independent sites/samples within a single mouth. Presence of the marker P. gingivalis (and P. intermedia) relates closely to periodontal pocketing while presence of A. actinomycetemcomitans does not have this pocket-associated characteristic. There was no significant relationship between presence of the marker organisms and the number of teeth in a mouth, and in the periodontal practice patients there was no significant effect of gender on occurrence of the marker organisms. A. actinomycetemcomitans and the other 2 markers were found over the entire age range (12 to 75) of our patients. Regular periodontal treatment reduced occurrence of all marker organisms and increased the frequency of marker-negative patients and sites. Occurrence of the marker organisms above immunoassay threshold levels appears to represent how receptive a patient is to each individual organism. Most patients appear receptive to the presence of P. intermedia whether treated or not. Significantly fewer patients who underwent regular treatment show the presence of P. gingivalis or A. actinomycetemcomitans when compared to untreated patients. Diagnostic application of microbial markers requires ongoing clinical assessment of patients and careful clinical judgment. 1391.

Serum IgG2 level, Gm(23) allotype and FcgammaRIIa and FcgammaRIIIb receptors in refractory periodontal disease

The purpose of this investigation was to compare the levels of serum IgG2, the frequency of detection of Gm(23)-negative allotype and frequency of detection of FcgammaRIIa and FcgammaRIIIb receptor haplotypes in 32 refractory, 54 successfully treated and 27 periodontally healthy individuals. Refractory subjects showed mean full mouth attachment loss and/or >3 sites with attachment loss >2.5 mm within 1 year after both scaling and root planing, and surgery plus systemically administered tetracycline. Successfully treated subjects showed mean attachment level gain and no sites with attachment loss >2.5 mm 1 year post-therapy. Periodontally healthy subjects exhibited no pocket depth or attachment level >3 mm, and no evidence of progressing disease during 1 year of monitoring. Blood was obtained from each subject at baseline. Serum IgG2 and Gm(23) allotype were determined using radial immunodiffusion. DNA was extracted from whole blood and the FcgammaR genotypes determined using PCR and allele specific oligonucleotide probes. Significance of differences among clinical groups were sought using the Kruskal-Wallis or chi-square tests. Associations between 2 or more variables were tested using regression analysis. Refractory subjects exhibited higher mean attachment loss and pocket depth than successfully treated or periodontally healthy subjects. Smoking status did not differ significantly among groups. No significant differences in serum IgG2 levels and frequency of detection of Gm(23)-negative allotype were observed among the clinical groups. Serum IgG2 level was positively associated with the number of serum antibody responses to subgingival species (r=0.51, p<0.001). Subjects with the Gm(23)-negative allotype exhibited lower mean levels of serum IgG2 (3.06+/-0.3 versus 3.9+/-0.2, p<0.01) and mean number of serum antibodies to subgingival species (17.7+/-1.7 versus 23.3+/-1.4, p<0.05) than allotype positive individuals. No significant differences in FcgammaR haplotype distribution were observed among the 3 clinical groups. Associations of serum IgG2 level, Gm(23) allotype, FcgammaRIIa and FcgammaRIIIb receptor haplotypes and smoking status were weakly related or not related to clinical status. This lack of relationship may have been due to a reality of no relationship, or the inadvertent pooling of subjects where these factors were of primary importance with subjects in whom these factors played a less important role.

Rapid evaluation of serum and gingival crevicular fluid immunoglobulin G subclass antibody levels in patients with early-onset periodontitis using checkerboard immunoblotting

A method was developed to evaluate the presence of immunoglobulin G (IgG) subclass (1-4) antibody to Actinobacillus actinomycetemcomitans, serotype b (strain Y4) in patients with early-onset periodontitis on a single nitrocellulose membrane. Sera from 30 early-onset periodontitis patients and gingival crevicular fluid samples from 2 patients were collected and tested with four different preparations of A. actinomycetemcomitans (Y4). The principle steps of the assay are: a) binding of the bacterial antigen (Y4) and the anti-human IgG antibody (capture antibody) in parallel lanes on nitrocellulose membranes; b) incubation of known concentrations of the IgG subclasses 1, 2, 3 and 4, as well as a dilution of serum and/or gingival crevicular fluid from patients in lanes perpendicular to the antigen lanes; c) incubation of the membranes with the corresponding peroxidase conjugated anti-human IgG subclass secondary antibody; d) detection of positive signals by enhanced chemiluminescence. The blots were evaluated by visual comparison to a series of blots containing known concentrations of IgG subclasses. The method was used to rapidly screen a relatively large number of patient sera and gingival crevicular fluid samples for IgG subclasses in a cost-effective assay. The predominant IgG subclass found in early-onset periodontitis was IgG2.

Attachment loss and serum antibody levels against autologous and reference strains of Actinobacillus actinomycetemcomitans in untreated localized juvenile periodontitis patients

Immunological data have been suggested to be a potential tool in the diagnosis, classification and monitoring of periodontal diseases. However, the role of circulating antibodies in periodontal patients is poorly understood. Patients suffering from localized juvenile periodontitis (LJP) are often reported to show high titers of serum IgG antibodies against Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), but several affected patients do not. Most studies use well-known reference strains of the bacterium for testing against the patients' sera. The aim of the present investigation was to study the relationship between serum IgG antibody levels to autologous A. actinomycetemcomitans strains and clinical attachment loss (CAL). In addition, we wanted to assess the patients' serum titers against 4 well-known reference strains of the bacterium as well as their general potential immunoglobulin response. Intravenous blood samples were taken from 23 LJP patients and 10 healthy individuals, and autologous A. actinomycetemcomitans strains were cultured from 18 of the LJP patients. CAL was measured at 4 different sites around all present teeth and assessed as a % of teeth with at least 1 site moderately > or = 2 < 5 mm) or severely (> or = 5 mm) involved. An enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the serum titers of IgG antibodies to A. actinomycetemcomitans antigens. No significant correlation was found between serum IgG antibody titers to autologous strains and CAL. However, there was a trend that low responders had more moderately affected teeth than had high responders and patients with undetectable A. actinomycetemcomitans levels, which is in agreement with a hypothetically protective role of the antibodies. The total counts of immunoglobulin assessed in all participants showed that the predominant class was IgG and the reference group displayed significantly less (p < 0.05) IgG and IgG1 counts than the LJP patients. Both the reaction pattern against reference and autologous strains varied widely. We conclude that the specific antibody response against A. actinomycetemcomitans shows a weak correlation to clinical attachment levels in LJP patients.

Estimation of serum antibody to subgingival species using checkerboard immunoblotting

Measurement of serum antibody to subgingival bacterial species has been useful in discriminating possible periodontal pathogens and in assessing the host's immune response to subgingival species. An immunoassay system was developed to measure the level of serum antibody to multiple subgingival species in multiple serum samples on a single nitrocellulose membrane. The principle steps of the assay are the following: 1) binding of antigens from bacterial preparations and protein A in parallel lanes on nitrocellulose membranes; 2) incubation of known concentrations of human immunoglobulin as well as various dilutions of serum from patients in lanes perpendicular to the antigen lanes; 3) incubation of the membrane with a peroxidase-conjugated second antibody; 4) detection of positive reactions by enhanced chemiluminescence. Emitted light was captured on a photographic film in which the positive reactions appeared as squares at the intersections of antigens with appropriate antibody. Antibody was quantified using a laser densitometer to compare the signal intensity of unknown samples with the ones generated by known amounts of human immunoglobulin captured on the same membrane. The assay permitted simultaneous screening and/or quantification of antibody in as many as 45 serum samples against up to 45 bacterial species. The mean and standard error of the coefficients of variation for replicates within an assay averaged 7.3 +/- 2.3%. Coefficients of variation of the assay run on different days for serum antibody to a range of subgingival species averaged 10.1 +/- 2.1%. Checkerboard immunoblotting is a simple and rapid immunoassay to permit quantification and/or screening of antibody to multiple subgingival species or antigens in multiple serum samples.

Characteristics of systemic antibody responses of nonhuman primates to cell envelope and cell wall antigens from periodontal pathogens

The immune response of the primate, Macaca fascicularis, to cell envelope (CEA) or cell wall (CWA) antigens of several periodontal pathogens was examined to develop a strategy to interfere with ligature-induced periodontitis. Animals were parenterally immunized with CEA of either Porphyromonas gingivalis, Prevotella intermedia or a combination of CEA/CWA of Campylobacter rectus, Fusobacterium nucleatum and Actinomyces viscosus. Serum samples were taken every 2-4 weeks over a 4-month period, which included a 13-week interval with molar teeth ligated. All of the nonhuman primates in the study exhibited baseline levels of IgG, IgM and IgA antibody to formalinized whole cells of the bacteria. These levels increased significantly following immunization and were elevated above baseline throughout the remainder of the experiment. The largest change in antibody responses was seen in IgA antibody levels of P. gingivalis and C. rectus (42-fold above baseline), IgM antibody to P. intermedia, (41-fold increase) and IgG antibody to F. nucleatum and A. viscosus (32 and 63-fold increases). Moreover, the nonhuman primates exhibited differences in isotype response levels to whole microorganisms compared with the cell envelope antigens. These findings demonstrate the capacity of these nonhuman primates to produce an active immune response to microorganisms chronically colonizing the subgingival microbiota. Additionally, it appears that the bacteria may exhibit some unique differences in their immunogenicity as detected by the nonhuman primate and may contribute to the ability of the immune responses to effectively interact with these pathogens.

Principles of evaluation of the diagnostic value of subgingival bacteria

This paper describes steps in the process of evaluating subgingival bacteria assays for the diagnosis of periodontal disease. The first step examines the infectious etiology of periodontal disease in pointing to specific oral bacteria as periodontal pathogens. Second is characterization of the laboratory test to detect and quantitate these pathogens as to sensitivity, specificity, and positive and negative predictive value. Third is the role of the laboratory test in the diagnosis of the different forms of periodontal disease which is related to the current clinical rather than microbiological definition of these diseases. The fourth and most important step is an analysis of the significance of subgingival bacterial tests in clinical decision-making.

Children, adolescents and periodontal diseases

OBJECTIVES

This manuscript attempts to critically review current literature regarding the natural history, aetiology and pathogenesis of the common periodontal diseases to affect children and adolescents. The logic behind the emergence of a new classification in the early 1990s is explained and potential problems with the interpretation of such systems outlined.

DATA SOURCES

The manuscript focuses upon recent developments, reported in the international periodontal literature, aimed at unraveling the molecular basis for this group of diseases. The concept of one disease type progressing with time to another disease within the same individual is discussed, and early data presented that indicate the possibility of microbial transmission from deciduous to permanent dentition's within a subject.

CONCLUSIONS

It is concluded that differing classification systems for adolescent and childhood periodontal diseases may lead to confusion within the dental profession, unless the clinical and molecular basis for such diseases is fully understood. Further advances in basic research using molecular biology tools should assist in our understanding of the aetiopathology at a molecular level and hopefully lead to the development of new treatment strategies.

Immunoglobulin allotypes and immunoglobulin G subclass responses to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in early-onset periodontitis

The present study was performed to estimate the observed frequencies of the immunoglobulin heavy-chain (Gm) and light-chain (Km) allotypes among patients with early-onset periodontitis (EOP) and their effect on the IgG2 subclass responses against Actinobacillus actinomycetemcomitans Y4 and Porphyromonas gingivalis 381, respectively. Sixty-nine EOP patients, including 11 with localized juvenile periodontitis (LJP), 19 who had LJP, 15 with LJP-rapidly progressing periodontitis (RPP), and 24 with RPP, were examined for the Gm and Km allotypes by a hemagglutination inhibition test. Levels of immunoglobulin G2 (IgG2) antibodies against the two organisms were determined by enzyme-linked immunosorbent assay. Fifty race- and age-matched, periodontally healthy subjects were also included as a control group. The observed frequencies of the Gm haplotype afnb and Km(1) were significantly higher in the RPP and LJP groups, respectively. The G2m(n)+ group of those with RPP and the Km(1)+ group of those with LJP had significantly higher levels of IgG2 antibodies to A. actinomycetemcomitans and P. gingivalis, respectively. The results indicate that linkage disequilibrium of the G2m(n) locus in RPP patients or the Km(1) locus in LJP patients may be associated with high IgG2 antibody responses to the respective bacteria. It was reasoned that the IgG2 antibody responses are associated with the immunoglobulin allotypes. The function of IgG2 antibodies in their reaction to different bacterial antigens may be interpreted as either protective or nonprotective in the two different types of EOP (i.e., LJP and RPP).

Serum antibody response to Actinobacillus actinomycetemcomitans in Down's syndrome

Persons with Down's syndrome (DS) are susceptible to severe and precocious periodontal disease. Several organisms have been implicated in the etiology of periodontal disease, including Actinobacillus actinomycetemcomitans (Aa). It is unknown whether circulating antibodies correlate with the severity of periodontal disease in DS. This study determined the circulating antibody titers to Aa in sera of DS and normal patients. Eleven DS patients with periodontal disease (pocket depth > 4 mm), five DS patients with gingivitis (inflammation and pocket depth < or = 3 mm), and 10 non-DS healthy subjects had blood drawn and analyzed for antibody response to Aa. Conventional enzyme-linked immunosorbent assay (ELISA) with goat anti-human IgG was performed for Aa-reactive serum diluted 1:200 to 1:12,800. Geometric mean titer was calculated, and significant differences were noted between the control group and the DS groups (p = 0.05), with the DS periodontal group having the highest response, followed by the DS gingivitis and normal controls, respectively. The DS groups were not significantly different. DS patients may exhibit a higher Aa antibody response, due to the presence of the organism, previous exposure, or in proportion to the extent of their periodontal condition.

Longitudinal changes in antibody avidity to Actinobacillus actinomycetemcomitans in periodontitis

Longitudinal investigations concerning immunological responses and periodontal disease activity support a relationship between serum antibody levels and the micro-organisms associated with dental plaque. To define this host response further, we studied the relationship of antibody avidity to Actinobacillus actinomycetemcomitans (Aa) in 11 adult periodontitis and 6 localized juvenile periodontitis (LJP) patients with Aa infections. Patients were monitored every 3-4 months for immunological and clinical variables including probing pocket depths (PD), bleeding on probing (BOP), plaque index (PLI), and the number of disease active sites (DA). Avidity indices were determined using an ELISA and significant changes from each patients' baseline level were determined. The results showed different response patterns between and within the patient groups. A subset of the subjects experienced significant changes in antibody avidity over time. Between group comparisons yielded no significant differences in the number of positive or negative avidity index changes, although there were more frequent changes in the disease active adult periodontitis group. There were also no significant correlations between clinical parameters and antibody avidity, although there were changes in the clinical parameters between baseline and significant avidity change points, and also between baseline and the determination of active disease. Further studies will be necessary to define fully the role of antibody avidity and its relationship to the pathogenesis of periodontal diseases.

Current concepts in diagnosis and treatment of periodontitis

This article describes some areas of periodontal research and current opinions regarding detection of disease progression, as well as risk indicators and risk factors associated with disease progression. Longitudinal probing of periodontal attachment level is considered the gold standard for detection of disease activity although there are problems with this concept. Digital subtraction radiography can assist in the detection of minor changes of alveolar bone height and density. Risk factors such as composition of subgingival plaque and gingival crevicular fluid, as well as the effect of smoking are discussed. Adjunctive treatment with both antibiotics and nonsteroidal anti-inflammatory drugs, systemic or local, seems to be helpful in some forms of disease. Immunization to prevent colonization of tooth surfaces and pockets by periodontal pathogens does not seem to be feasible in the near future.

Avidity of antibody responses to Actinobacillus actinomycetemcomitans in periodontitis

We designed a study to examine the serum IgG antibody avidity characteristics in: (i) normal subjects (N); (ii) Actinobacillus actinomycetemcomitans-infected adult periodontitis (AP Aa+); (iii) A. actinomycetemcomitans-infected localized juvenile periodontitis (LJP Aa+); and (iv) AP subjects (AP) with various antibody patterns and disease presentation. Although there were significant elevations in antibody levels for AP Aa+ and LJP Aa+ patients compared with AP and normal patients (P < 0.0001), there were no significant differences in the avidity indices (AI). Correlations of antibody levels to avidity revealed that functional activity of the antibody as measured by avidity was independent of antibody levels. Increasing antibody levels correlated with an increase in the number of infected sites, yet there was a trend for A1 to decrease with increased infection. Avidity indices for all patient groups did not appear to show a strong biologic relationship to plaque; however, in AP Aa+ and LJP Aa+ patients there was a generally positive relationship between avidity and bleeding on probing or pocket depth. In AP Aa+ and LJP Aa+ patients, and in AP patients there was a positive relationship of avidity through a threshold of approximately 8 active disease sites. This study hypothesized that antibody avidity to A. actinomycetemcomitans could help to explain the relationship between the active host response and chronic infection with this pathogen. The results provide evidence that both antibody levels and avidity may contribute to the variation in host resistance to infection and disease associated with A. actinomycetemcomitans.

Antigen specificity of serum antibody in A. actinomycetemcomitans-infected periodontitis patients

We hypothesized that serum antibody with selected antigen specificities would relate to infection and disease in the patients and, thus, describe the characteristics of potential protective antibody. This study used serum samples from 24 periodontitis patients with subgingival infection and elevated serum IgG antibody to A. actinomycetemcomitans to define the antigenic specificities of IgG, IgM, IgA, and IgG1-4 antibody to A. actinomycetemcomitans strain Y4 outer membrane antigens (OMA). Uniform IgG antibody (> 70% of the patients) was noted to antigens with M(r) of 65, 38, 29, and 17 kDa. Both IgA and IgM specificities reflected those shown for IgG in each patient. IgG1 and IgG2 antibody reacted with several OMA bands in each patient, while IgG3 antibodies were directed to numerous OMA bands in many patients and represented the most broad-based response. The IgG4 response patterns were limited to a few OMA bands. We noted a prominent occurrence of IgG reactions with OMA bands that were characteristic for individual patients. The frequency of responses to OMA of higher M(r) (i.e., > 80 kDa) and to the 34-, 31-, and 24-kDa antigens was positively related to the total IgG antibody levels. Antibody reactive with OMA bands at 65-, 38-, 29-, 17-, 15-, and 11-kDa antigens was detected in patients with few to many teeth infected with A. actinomycetemcomitans. Furthermore, patients with a high percentage of teeth with > or = 6 mm pockets had a decreased frequency of responses to the high-M(r) antigens (i.e. > 90 kDa) as well as to the 58-kDa antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum immunoglobulin G subclass concentrations in periodontally healthy and diseased individuals

Patients with localized juvenile periodontitis (LJP) often have high titers of antibody reactive with the serotype-specific immunodominant carbohydrate antigen of Actinobacillus actinomycetemcomitans serotype b. The vast majority of this A. actinomycetemcomitans serotype b-specific antibody is immunoglobulin G2 (IgG2). The present study was undertaken to determine whether the overall total levels of IgG2 in the sera of LJP patients are elevated. LJP patients and nonperiodontitis (NP) controls matched for age, race (black and white), and gender were studied. Additional controls included patients with adult periodontitis (AP) and patients similar in age to LJP patients but with the more-severe, generalized form of early-onset periodontitis (SP). Sera from over 700 periodontally characterized subjects were examined by using radial immunodiffusion to quantitate IgG2 as well as IgG1, -3, and -4, which were included for comparison. Serum IgG2 levels increased with age, and this was most dramatic around puberty. Black subjects in all periodontal groups had nearly 1 mg more IgG2 per ml than their white counterparts. Serum IgG2 levels were elevated (about 30 to 40%) in LJP patients of both races compared with their age- and race-matched NP controls (P < 0.01). In contrast, SP patients and AP patients had IgG2 levels comparable to their age- and race-matched NP controls. No other IgG subclass concentration correlated with periodontal diagnosis except for IgG3, which was elevated in white LJP patients. We reason that the high levels of serum IgG2 in LJP may be helpful in localizing periodontal destruction.

Early-onset periodontitis in Hispanic-American adolescents associated with A. actinomycetemcomitans

This study examines the frequency of oral disease in an adolescent population, and assesses the relationship to Actinobacillus actinomycetemcomitans. A total of 470 eighth grade students from San Antonio, Texas, were examined clinically for number of teeth, frequency of gingival inflammation, frequency of sites with BOP, and frequency of sites with 3-5 mm pockets, and pockets > 5 mm. The population ranged in age from 12 to 17 yr and was 93% Hispanic. Heavy accumulations of plaque and calculus were frequently observed and were associated with gingival inflammation, as 95.6% of the students exhibited bleeding on probing, and 99.6% of the students presented with at least on quadrant of inflammation upon visual examination. Significantly, 25.7% of the students exhibited early-onset periodontitis (EOP) with 1.7% diagnosed as LJP. Many students exhibited substantial levels of plaque and calculus, but no clinical evidence of loss of attachment. Subjects with periodontitis (EOP or LJP) presented with elevated systemic IgG antibody to A. actinomycetemcomitans serotype b and subgingival plaque samples positive for the microorganism. These results describe the prevalence of EOP/LJP in an adolescent Hispanic population from South Texas. The findings support that A. actinomycetemcomitans may represent a pathogen in periodontitis and while oral health care may be poor, contact with the microorganism appears to be required to initiate disease in this population.

Subgingival distribution of A. actinomycetemcomitans in periodontitis

This investigation developed an experimental design that (1) detailed the distribution of A. actinomycetemcomitans in subgingival plaque related to the level of serum antibody to this pathogen; (2) used broad based subgingival plaque sampling to allow a definition of the distribution of A. actinomycetemcomitans infection in periodontitis patients; (3) described the distribution of A. actinomycetemcomitans serotypes in patients and within sites; and, (4) assessed how this infection impacted upon local clinical symptoms of disease. We noted a significant positive relationship between the level of IgG anti-A. actinomycetemcomitans antibody and the frequency of teeth infected until nearly 13 teeth demonstrated an infection. Furthermore, the results showed a generally negative relationship between the antibody level and the burden of A. actinomycetemcomitans in the infected sites. Interproximal sites associated with first molar teeth were the predominant sites for subgingival colonization; incisors were also frequently infected in this population. The first molar teeth also exhibited the greatest level of A. actinomycetemcomitans, while the incisors demonstrated a high level of A. actinomycetemcomitans in individual sites. The results clearly indicated the majority of the sites sampled were colonized by a single serotype of A. actinomycetemcomitans. We detected A. actinomycetemcomitans nearly 2 x times more frequently and a significant increase in the proportion of A. actinomycetemcomitans was found in samples obtained from teeth with bleeding on probing. The results also showed a significant trend for both pocket depth and attachment levels to be related to the presence and proportion of A. actinomycetemcomitans in the subgingival plaque. These findings detail the microbiological, immunological and clinical characteristics of a unique subset of periodontitis patients that appear to exhibit disease associated (caused?) with A. actinomycetemcomitans infection irrespective of clinical categorization. The results support a unique distribution of this microorganism in the subgingival ecology that is related to active host immune responses and clinical presentation of the tooth.

Specificity and levels of oral and systemic antibodies to Actinobacillus actinomycetemcomitans

Salivary and gingival crevicular fluid antibodies and systemic antibodies were analysed for levels and specificity against Actinobacillus actinomycetemcomitans components. The major reactivity of salivary and serum IgA1 and IgA2 antibodies to the periodontal pathogen A. actinomycetemcomitans was against bands between 14 and 83 kD for IgA1 and bands between 14 and 68 kD for IgA2 in Western blot. In addition to specific binding, there was also a hitherto unrecognized Fc-mediated binding of IgG antibodies to an A. actinomycetemcomitans component around 50 kD. Serum IgG antibodies to A. actinomycetemcomitans leukotoxin displayed the highest median value and only 1 individual showed salivary IgM antibodies in ELISA. Elevated levels of gingival crevicular fluid IgA2 antibodies indicated a local production of IgA from periodontal tissues. Using synthetic peptides, several distinct epitopes on the leukotoxin were recognized by both salivary and serum IgA antibodies.

Transmission of Actinobacillus actinomycetemcomitans in families of adult periodontitis patients

At present Actinobacillus actinomycetemcomitans is regarded as an important microorganism in the etiology of some forms of periodontitis. The purpose of the present investigation was to study the number of Restriction Endonuclease Analysis (REA)-types present in the oral cavity of A. actinomycetemcomitans positive subjects and to study the possibility of transmission of A. actinomycetemcomitans within families of adult periodontitis patients. DNA of A. actinomycetemcomitans isolates was digested with a combination of the restriction endonucleases PstI and BamHI, after which the DNA fragments were separated by agarose gel-electrophoresis. To study the number of REA-types, multiple A. actinomycetemcomitans isolates obtained from 8 different sites in the oral cavity of five subjects were typed. The results showed that in most cases only one REA-type is present. In the 13 families investigated in 4 of the 26 children (15%) and in 1 of the 13 spouses (8%) of the adult periodontitis patients an indistinguishable REA-type was found within the families. This suggests that also in the case of adult periodontitis transmission of A. actinomycetemcomitans is possible, but does not seem to occur easily.

Specific antibodies against Actinobacillus actinomycetemcomitans in serum and saliva of patients with advanced periodontitis

The aim of the present study was to discover any possible correlation between specific antibodies against Actinobacillus actinomycetemcomitans (A.a.) in serum and saliva. The test group consisted of 38 patients aged 31-68 yr (mean 49) with advanced periodontitis. Twenty-nine subjects aged 23-67 yr, without periodontal destruction, formed a control group with a reference level of specific salivary antibodies against A.a. A subgingival plaque sample for culturing A.a., a specimen of stimulated whole saliva, and a sample of venous blood were taken from each subject of the test group. Specific IgG and IgA antibodies against A.a. were determined from serum and stimulated whole saliva by means of the ELISA test. Fifteen of the patients (39%) had cultivable A.a. Six of the 15 A.a. culture-positive patients and one of the 29 reference subjects exhibited very high antibody titers against A.a. in saliva. Specific IgG and IgA antibodies in saliva correlated highly significantly with the corresponding antibody values in serum among the patients in the test group. It was concluded that among patients with severe adult periodontitis, the less invasive saliva sample has a diagnostic value equal to that of the serum sample concerning specific antibodies against A.a.

Immunoglobulin class and subclass distribution of antibodies reactive with the immunodominant antigen of Actinobacillus actinomycetemcomitans serotype b

The aims of this study were to determine the immunodominant antigens of Actinobacillus actinomycetemcomitans serotype b (Aab) for the different immunoglobulin (Ig) classes and subclasses and to determine the relative levels of these different Igs in serum. Seropositive early-onset periodontitis patients were sampled, and the Ig classes IgG, IgA, and IgM and subclasses IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2 were studied. Reactivity with Aab antigens was assessed by using the Western blot (immunoblot) in limiting dilution analysis and radioimmunoassay with sera from 13 early-onset periodontitis subjects. A smeared antigen in the upper portion of the immunoblots, typical of high-molecular-weight LPS, was immunodominant for IgG, IgA, IgM, IgG1, IgG2, IgG3, IgA1, and IgA2. This smeared antigen was present in every patient for all of these Igs at the endpoint. A few additional antigens were also present at the endpoint in some patients, but none were present in more than half of the subjects. The distribution of antibody titers by Ig classes reactive with the Aab immunodominant antigen was IgG > IgA > IgM. The distribution of antibody titers by IgG subclass was IgG2 > IgG1 approximately IgG3. Further quantitation by radioimmunoassay revealed that the mean concentration of IgG2 (65.7 micrograms/ml) was significantly greater than that of IgG1 (8.8 micrograms/ml). The IgA subclass distribution was IgA1 >> IgA2, with IgA1 apparently being second only to IgG2. Therefore, the Aab antigen eliciting the highest antibody level in virtually all Ig classes and subclasses appeared to be lipopolysaccharide, and IgG2 was markedly elevated over all other serum Ig classes or subclasses reactive with Aab.

Analysis of the genetic control of antibody response to Actinobacillus actinomycetemcomitans by immunoblotting inbred strains of mice

Genetic regulation of the immune response may be involved in the onset and progression of an early-onset type of periodontitis. We analyzed the genetic control of the primary antibody response to Actinobacillus actinomycetemcomitans in inbred strains of mice using an immunoblot technique. Mice of 5 independent inbred strains, 6 H-2 congenic strains and 4 B10 intra-H-2 recombinant strains were immunized with sonicated extracts of A. actinomycetemcomitans. On the seventh day their sera were examined for reactivity to the antigenic components of this organism. Western blot analysis clearly distinguished 2 different groups of antigens, one consisting of common antigens (molecular weights, 28, 34, 36 and 40 kDa) that reacted with sera from all strains and one consisting of specific antigens (molecular weights 31, 65 and 69 kDa) that reacted only with sera from distinct strains. Blot analysis of sera from H-2 congenic strains demonstrated that the reactivity to the second group of antigens was regulated by the H-2 complex. In B10 intra-H-2 recombinant strains, only the I-Ab allotype strains produced immunoglobulin G antibody that reacted to the 65 kDa antigen. This evidence indicates that the primary immune response to the A. actinomycetemcomitans antigen with a molecular weight of 65 kDa is controlled by genes in the I-A subregion of the H-2 complex. This 65 kDa antigen was also highly reactive with some human sera from early-onset periodontitis patients. Further analysis of this antigen is required.

Titer and subclass distribution of serum IgG antibody reactive with Actinobacillus actinomycetemcomitans in localized juvenile periodontitis

Most patients with localized juvenile periodontitis (LJP) manifest serum IgG antibodies specifically reactive with antigens of Actinobacillus actinomycetemcomitans serotype b (Aa-b). Whether these antibodies are protective, destructive, or irrelevant to the progress of the disease remains unclear. We report results of studies aimed at assessing the subclass IgG responses in 35 LJP patients and 35 periodontally normal control subjects using well-characterized monoclonal antibody subclass reagents in an enzyme-linked immunosorbent assay. Our data show that the mean value for total IgG reactive with antigens of Aa-b was more than sevenfold higher for patients than for normal control sera (2349.6 micrograms/ml for patients vs 332.2 micrograms/ml for controls). Individual patients and control subjects were classified as high- or low-titer, using twice the median value for total anti-Aa-b IgG in control sera as the cutoff. Of 35 patients, 26 (74%) were high-titer, and 9 (26%) were low-titer. This compares to 5 normal control subjects (14%) high-titer and 30 (86%) low-titer. IgG2 accounted for the major quantitative response in both patients and control subjects. Indeed, the mean IgG2 values for both concentration and percentage of total specific IgG were greater than the combined values for specific anti-Aa-b IgG1, IgG3, and IgG4. Of the 26 high-titer sera, IgG2 predominated in 24, with IgG1 and IgG3 predominating in 1 each; IgG2 predominated in only 2 of the low-titer sera.

Microbiological and clinical monitoring of non-localized juvenile periodontitis in young adults: a report of 11 cases

It has been shown that patients with localized juvenile periodontitis (LJP) often harbor Actinobacillus actinomycetemcomitans in the subgingival area. However, little is known of the oral microflora in non-LJP juvenile periodontitis patients with less extensive disease. The purpose of this study was to describe the microflora and clinical parameters of young adults with minor to moderate periodontitis during treatment for a period of 1 year. Eleven patients 15 to 16 years of age were studied. All of them had 4 to 8 mm loss of attachment at minimally one site, but the typical clinical description of localized juvenile periodontitis was an exclusion criterion in this study. Microbiological examination of the deepest periodontal pocket and of the tongue revealed that 6 patients harbored Actinobacillus actinomycetemcomitans and 5 harbored Porphyromonas gingivalis. Almost all subjects showed relatively high proportions of Prevotella intermedia, Campylobacter rectus, motile organisms, and spirochetes. On the basis of clinical and microbiological parameters the 11 patients could be assigned to 1 of 2 groups. Six cases had moderate periodontal breakdown with loss of attachment at 7 to 44 sites. All harbored A. actinomycetemcomitans and 5 of them P. gingivalis. These 6 cases responded relatively well to initial treatment despite the continued presence of A. actinomycetemcomitans. The other group consisted of 5 cases with relatively minor periodontal breakdown; i.e, 1 or 2 sites with 4 to 6 mm loss of attachment. Neither A. actinomycetemcomitans nor P. gingivalis was detected in the deepest pocket of these patients. All 5 responded well to initial treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristics and utilization of antibody measurements in clinical studies of periodontal disease

The detection and quantitation of immune responses to infections have long been used as a diagnostic tool in medical infections. Recently, increasing evidence has supported that active, specific antibody responses to selected members of the subgingival microbiota are noted in periodontitis patients. This report describes the various specificities of this antibody as they relate to periodontitis classification and prognosis. The functional aspects of the serum antibody have come under increasing scrutiny to understand better the potential immunologic mechanisms acting in the periodontium. Data are available that describe opsonizing potential, complement fixing ability, blocking functions, and anti-toxic capacity for the antibody. Longitudinal alterations in specific antibody levels are shown to relate to infection and accompany changes in the burden of a specific microorganism in the subgingival plaque. Thus, these antibody changes could be useful indicators of altered host-parasite interactions that presage a disease-active episode. Finally, studies were designed to examine the ability of antibody to reflect the effects of treatment on the disease. The results indicated that specific antibody levels change with mechanical, antimicrobial, and anti-inflammatory treatments. The findings described in this report suggest that evaluation of the level and specificity of serum antibody can be a beneficial adjunct in designing and implementing clinical studies delineating the initiation, progression, and treatment of periodontitis.

Differential diagnosis in clinical trials of therapy for periodontitis

For purposes of clinical trials of therapies for periodontitis, it is recommended that population samples be identified as adult periodontitis (systemically modified or not systemically modified), early onset periodontitis (localized or juvenile, generalized or rapidly progressive, or associated with systemic disease), or necrotizing ulcerative periodontitis, avoiding overlapping criteria. Population samples of adult or early onset periodontitis modified by or associated with systemic conditions should be used in clinical trials only when the intent is to study effect on the specifically modified condition. Objective identification of the modifying systemic condition should be required for all subjects in such trials. Population samples should be homogeneous for the diagnosis, whether systemically modified or not. Refractory periodontitis, prepubertal periodontitis, and periodontitis associated with systemic disease are not recommended as useful descriptors of population samples without discrete identification of underlying systemic abnormality for all included subjects. Definition of population sample by a bacteriological or a host response feature is not recommended unless the trial is specifically aimed at that feature and the sample is homogeneous for it. All trials of efficacy should include physical or radiographic measurement of attachment level or bone height as a critical outcome variable. Results from trial in one form of periodontitis should not be applied directly to other forms.

Longitudinal monitoring of humoral antibody in subjects with destructive periodontal diseases

Fifty-one subjects (16-61 years old) with evidence of prior destructive periodontal disease were monitored clinically and immunologically at bi-monthly intervals for up to 5 yr. Periodontal disease activity, determined as new attachment loss, was detected in 33 of these subjects. Only 4 of 51 subjects failed to show an elevated serum antibody level to any of the 18 subgingival species tested. The antibody level threshold established for periodontally healthy subjects was exceeded most often in diseased subjects with serum antibody to Actinobacillus sp., P. gingivalis, E. corrodens, C. concisus, F. nucleatum and P. intermedia in that order. In general, most serum antibody levels to subgingival species remained relatively consistent for periods as long as 5 yr. However, major increases and decreases in antibody could be detected to at most one or two species in individual subjects. In addition, prolonged, steady increases and decreases in antibody to specific species could be detected in certain subjects. These findings suggest that major changes occurring in serum antibody may reflect fluctuations in the nature of the infection. Differences were observed in the antibody level to specific species when subjects were divided into subsets on the basis of clinical criteria. These included high levels of antibody to A. actinomycetemcomitans Y4 in LJP and RPP subjects and to A. actinomycetemcomitans 29523 in LJP and GJP subjects.