IgG subclasses in human periodontal disease. I. Distribution and incidence of IgG subclass bearing lymphocytes and plasma cells

Platelets as a Novel Target for PPAR?? Ligands

Peroxisome proliferator-activated receptor gamma (PPARgamma) is an important transcription factor for lipid and glucose metabolism. Currently, the PPARgamma ligands rosiglitazone and pioglitazone are used for the treatment of type 2 diabetes mellitus because they are potent insulin sensitizers. Recently, PPARgamma has emerged as an important anti-inflammatory factor. Platelets, anucleate cells involved in hemostasis, have also been implicated as key contributors to inflammation, because they produce many pro-inflammatory and pro-atherogenic mediators when activated. Surprisingly, it was discovered recently that platelets contain PPARgamma and that PPARgamma ligands, both natural and synthetic, inhibit platelet activation and release of bioactive mediators. In particular, release of soluble CD40 ligand (sCD40L) and thromboxane (TXA(2)) was inhibited by PPARgamma ligands in thrombin-activated platelets. CD40L signaling induces pro-inflammatory processes in many cell types, and increased blood levels of sCD40L are closely associated with inflammation, diabetes, and cardiovascular disease. Targeting platelet PPARgamma will, therefore, be an important treatment strategy for the attenuation of chronic inflammatory processes and prevention of thrombus formation.

Immune processes in periodontal disease: a review

The inflammatory and immune processes in periodontitis are complex and, although a great deal of information is available, many questions remain. Variation in human susceptibility to periodontitis has long been accepted, but the pathological basis of this is poorly understood. Similarly, we know little of the differences, if any, between the pathology of chronic and aggressive periodontitis. Genetics and environmental influences play a role in the susceptibility process, but if and how that translates through the immune and inflammatory processes to produce the plasma cell-dominated lesions seen in periodontitis remain to be elucidated. This review will focus on immunological aspects of the inflammatory changes seen in gingivitis and periodontitis, addressing both humoral and cellular responses to the microbial insult from dental plaque. A tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogens and thus a predisposition to periodontitis. The issues to be considered include: 1) homing of immune and inflammatory cells to target tissues; 2) their local proliferation and synthetic activity; 3) the cytokine profile of the leukocytes; 4) the immunoglobulin subclasses of locally produced antibodies; 5) mucosal and systemic immune characteristics of the response; 6) the humoral immune response in periodontal health and disease states; and 7) the antigenic target of the immune response in periodontal lesions.

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.

Protective effect of serum antibodies against a 110-kilodalton protein of Actinobacillus actinomycetemcomitans following periodontal therapy

Thirty-four adult patients with untreated periodontitis were randomly assigned to receive full mouth scaling alone or scaling with an adjunctive antimicrobial therapy, both followed by supportive periodontal therapy. At 24 months, specific serum immunoglobulin A (IgA), IgG and IgG subclass antibody reactivities against a 110-kDa protein of Actinobacillus actinomycetemcomitans were assessed by Western blot. In patients harboring A. actinomycetemcomitans intraorally, the IgG4 antibody reactivity against the 110-kDa protein of A. actinomycetemcomitans was associated with significantly increased survival rates of teeth and of sites not exhibiting 2 mm or more of probing attachment loss. The same trend was found for IgG3 and IgG2 antibody reactivities, but it was statistically insignificant. No association with clinical treatment outcome was observed for IgA, IgG and IgG1 antibody reactivities. The results indicated that systemic IgG4 antibody reactivity against the 110-kDa protein of A. actinomycetemcomitans may have a protective effect against periodontal disease progression in patients harboring A. actinomycetemcomitans and receiving periodontal therapy.

In situ localization of cell synthesis and proliferation in periodontitis gingiva and tonsillar tissue

OBJECTIVE

Previous work indicates that large numbers of B and T cells accumulate in the periodontal soft tissues although we know little about cellular synthetic activity and proliferation in this site. The aim of this study was to examine lymphocytic cell synthetic activity and proliferation in periodontitis gingiva and compare this to a known site of leucocyte proliferation, namely the oropharyngeal tonsils.

MATERIALS AND METHODS

Messenger RNA (mRNA) and 28S ribosomal (28S rRNA) expressing cells in formalin-fixed/paraffin-embedded gingival and tonsillar tissue sections were detected by in situ hybridisation (ISH) using poly-deoxyribothymidine and 28S probes respectively. In addition S-phase proliferating and cycling cells were also detected by ISH with histone probes and by Ki-67 immunohistochemistry. Ten gingival biopsy samples were obtained from adult periodontitis patients and five tonsillar biopsies from tonsillectomy patients.

RESULTS

Both mRNA and 28S rRNA-expressing cells were detected in all the samples tested. Plasma cells showed the strongest signal for the two probes and slight to moderate staining could be seen in epithelium, fibroblasts and endothelial cells. In contrast, gingival lymphocytes were either weakly stained or were unstained for these probes of synthetic activity. In tonsils, most lymphocytes in germinal centres showed moderate staining and mantol zone cells were much more weakly stained. In gingival samples, histone mRNA-expressing and cycling (Ki-67) cells were detected in 4/10, 10/10 cases respectively. These positive cells were mainly basal and suprabasal epithelial cells and a few mononuclear cells, whereas most germinal centre lymphocytes (B cells) were positive for this probe. The number of Ki67 positive cells was greater than histone mRNA bearing cells both in gingiva and tonsillar tissue. In contrast, mantol zone cells (mainly T cells) were sparsely stained by probes of cell proliferation.

CONCLUSION

These results indicate that local proliferation of B cells does not occur in periodontitis gingiva in contrast with tonsillar tissue, although plasma cells showed strong synthetic activity in both tissues. T cells did not appear to proliferate greatly nor undergo active synthesis in either of these tissues. These findings substantiate previous hypotheses that specific leucocytes predominate in the gingival tissue through selective homing rather than by local proliferation.

Tissue immunoglobulin G subclasses observed in immune-mediated dermatopathy, deep pyoderma and hypersensitivity dermatitis in dogs

A panel of monoclonal antibodies has been used to define three of the four subclasses of canine immunoglobulin G (IgG2, IgG3 and IgG4) in formalin-fixed tissues. These reagents, together with a polyclonal antiserum specific for the Fc region of canine IgG, were used in an immunohistochemical study of biopsies of skin from five normal dogs and from the lesions of canine pemphigus foliaceus in seven dogs, discoid lupus erythematosus in eight dogs, bullous pemphigoid in one dog, cutaneous drug eruption in two dogs, deep pyoderma in 13 dogs and hypersensitivity dermatitis in eight dogs. IgG autoantibody was identified in the skin of all the dogs with immune-mediated dermatoses by using the polyclonal reagent, and antibody of the IgG2 and/or IgG4 subclass was identified in the epidermis of three of the dogs with pemphigus foliaceus, two of those with discoid lupus erythematosus and in the dog with bullous pemphigoid. In all the lesions, the infiltrate of dermal plasma cells consisted of similar numbers of IgG2 and IgG4 bearing cells, with relatively few IgG3 positive cells. The total number of these cells was generally approximately the same as or greater than the number of cells labelled with the polyclonal reagent. There was no significant difference between the IgG-bearing plasma cell infiltrate in German shepherd dogs with deep pyoderma and that in dogs of other breeds. The infiltration of IgG2 and IgG4 bearing plasma cells into the skin of dogs with a range of cutaneous disorders was related to the selectively enhanced serum levels of these subclasses in the diseased dogs.

Gingival crevicular fluid antibody to Actinobacillus actinomycetemcomitans in periodontal disease

We identified antibody isotypes and subclass proportions in gingival crevicular fluid to understand the potential protective ability of these antibodies towards infection with Actinobacillus actinomycetemcomitans. Immunoglobulin G (IgG) 1-4 antibody levels to A. actinomycetemcomitans serotype b were quantified in serum and gingival crevicular fluid from 20 periodontitis patients who had at least one subgingival plaque sample with cultivable A. actinomycetemcomitans. The subclass antibody levels in the patients' sera were IgG1 = IgG2 > IgG3 > IgG4. A portion of the gingival crevicular fluid samples had IgG (15.7%; range: 0-52%) and IgA (2.5%; range: 0-15%) antibody that was significantly elevated compared with serum. Gingival crevicular fluid samples with elevated IgG antibody were analyzed for the subclass distribution and showed elevated IgG3 (58%), IgG4 (35%), IgG1 (25%) and IgG2 (25%) antibody in the gingival crevicular fluid. These results demonstrated a characteristic distribution of both serum and gingival crevicular fluid IgG subclass responses to A. actinomycetemcomitans. We also examined the sites with elevated antibody in each subclass for the presence of A. actinomycetemcomitans in the subgingival microbiota. The results showed that > 95% of sites with elevated IgG4 were colonized, whereas < 50% of sites with elevated IgG2 demonstrated this microorganism. IgG2 and IgG4 levels were primarily elevated in diseased sites, whereas IgG4 elevations were absent in healthy sites. The frequency and distribution of antibody in the gingival crevicular fluid as related to colonization with this microorganism were consistent with localized host-parasite interactions at individual tooth sites. The relative subclass distribution of elevated gingival crevicular fluid antibody was shown to be IgG3 > IgG4 > IgG2 = IgG1. These antibody types suggest that the potential exists for this local antibody to A. actinomycetemcomitans to play an important role in the gingival sulcus in relationship to colonization and clinical presentation.

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.

Serum antibody responses in human periodontitis to cellular components of Capnocytophaga

Serum levels of IgM, IgG and IgG-antibody subclasses directed against cell envelopes, lipopolysaccharides and cytoplasmic fractions from Capnocytophaga sputigena, C. gingivalis and C. ochracea were examined in age-, race- and sex-matched periodontally healthy (n = 25) subjects and subjects with adult periodontitis (n = 25). The envelopes and cytoplasmic fractions were obtained by ballistic disintegration of the cells and ultracentrifugation. Cell envelopes were treated with DNase, RNase and lysozyme. Lipopolysaccharides were obtained by hot phenol-water extraction and treated with DNase and RNase. The relative levels of the antibodies in response to the cell fractions were measured by the streptavidinbiotin micro enzyme-linked immunosorbent assay. Both groups showed IgM and IgG antibodies to each fraction of the three Capnocytophaga species, but the frequency of positive IgG subclass responses varied. The IgG4 responses were lower than the other subclasses. There were no significant differences between the IgM antibody levels of the two groups. However, the adult periodontitis group had significantly lower IgG antibody titres to the cell envelopes and cytoplasmic fractions of C. gingivalis and C. ochracea, and lipopolysaccharide of C. gingivalis. These results were reflected in the depressed levels of IgG1 and/or IgG2 to these cellular fractions from the same bacterial species. The adult periodontitis group also showed a lower level of IgG1 to the cytoplasmic fractions of C. sputigena without any depression in the total IgG antibody level. There were no significant differences between the groups in IgG3 and IgG4 antibody levels to any of the cellular fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Host mediators in gingival crevicular fluid: implications for the pathogenesis of periodontal disease

During the past few years, a considerable number of studies have examined different aspects of the host response in gingival crevicular fluid (GCF), including the relationship of specific markers to the active phases of periodontal disease. Various indicators of the acute inflammatory response (the lysosomal enzymes beta-glucuronidase and collagenase, the cytoplasmic enzyme aspartate aminotransferase, and the arachidonic acid metabolite PGE2) have been shown to be associated with clinical attachment loss in chronic adult periodontitis in man and experimental periodontitis in animal models. In contrast, the relationship of indicators of the humoral immune response in GCF to active periodontal disease is equivocal. Furthermore, a number of indicators of the cellular immune response have been identified recently in GCF (i.e., Interleukin-1 alpha, IL-1 beta, tumor necrosis factor-alpha), but their relationship to active phases of periodontal disease have not been studied. The polymorphonuclear leukocyte (PMN) is the cellular hallmark of acute inflammation. Evidence from the GCF studies suggests that hyperreactivity of these cells plays a critical role in the active phases of some forms of periodontal disease. Metabolic activation of PMN can be associated with a number of potentially destructive reactions. The major effector mechanism for tissue destruction that can be specifically identified with the PMN is the synergistic effect of the release of PMN proteases and the generation of reactive oxygen metabolites by these cells. Priming of the PMN, where the PMN response is enhanced by agents that do not initiate the response, may be an important mechanism for PMN activation in the crevicular environment; for example, cytokines such as IL-1 beta and TNF-alpha, and lipopolysaccharides released from subgingival Gram-negative bacteria, can serve this function. The hypothesis proposed here argues that in addition to the severe forms of periodontal disease that have been associated with qualitative or quantitative PMN defects, tissue destruction in the periodontum can be observed with hyperreactivity of these cells. These differing conclusions do not create a dilemma, but may represent opposite ends of a balance that is no longer in equilibrium.

Chemotaxis of germinal center B cells in response to C5a

An infiltrate of B cells and plasma cells is characteristic of certain chronic inflammatory lesions. However, mechanisms involved in the local accumulation of these cells have not been established. Efforts to demonstrate that B cells from normal animals can migrate in response to inflammation-induced chemoattractants have been inconclusive. The objective of this study was to determine if murine germinal center (GC) B cells could respond chemotactically to a C5a gradient. On successive days after secondary immunization, draining lymph nodes were harvested and the activated GC B cells isolated. These GC B cells were placed in modified Boyden chambers, incubated for 3 h and the distance the leading front of cells migrated through the filters was determined. The results show that GC B cells migrated to factors in zymosan- and lipopolysaccharide-activated serum. The migratory response demonstrated distinct kinetics. Cells isolated between 2 to 4 days after secondary immunization migrated, whereas cells isolated at day 0 and beyond day 6 did not. Checkerboard analysis revealed that the migratory response was attributable to both chemokinesis and chemotaxis. Anti-C5 inhibited the migration of day-3 GC B cells implicating C5 in the migration mechanism. Studies using recombinant C5a established that this C5 fragment was chemotactically active. In conclusion, GC B cells generally were not chemotactically active. However, at a particular stage of maturation B cells in the GC become responsive to C5a as a chemotactic agent. Thus, B cells from normal animals may respond chemotactically, and C5a may play a role in recruitment of recently activated B cells into inflammatory sites.

Importance of the host response in the periodontium

Immunological mechanisms have been implicated in the pathogenesis of periodontal disease for over 25 years. Studies throughout the 1970s established that advanced forms of the disease were dominated by B-cells/plasma cells while early and putative stable forms of the disease were dominated by T-cells/lymphocytes. Based on these observations, a model of disease was put forward which highlighted a possible T-cell/macrophage immunoregulatory imbalance being involved in disease pathogenesis. Studies throughout the 1980s have supported such a concept although the precise nature of this imbalance remains elusive. At the same time, clinical studies have established that patient susceptibility may be of overriding importance in determining disease outcome. In this context therefore, factors which influence this susceptibility should be fundamental in determining periodontal disease activity. These factors may include genetic variation between individuals in the way in which they respond to periodontopathic bacteria upon which environmental factors would be superimposed. These environmental factors would include anything that altered the balance between the host and the parasite and may be as diverse as recent viral infections resulting in T-cell anergy or physical and mental stress. Recent studies have shown that in elite atheletes, physical stress during training and competition leads to a suppression of mucosal immunity as evidenced by a reduction in salivary IgA. The subsequent effect of these environmental factors at the level of the periodontium, however, remains to be determined.

Immunologic mechanisms of pathogenesis in periodontal diseases: an assessment

Principal lines of evidence that immune reactions are central to the pathogenesis of periodontitis are reviewed. Necessary components of immunologic reactions are present in gingiva in the periodontal diseases. Differences between healthy and periodontitis patients with respect to some measures of immune function further indicate that immune reactions do occur in the gingiva during periodontitis. They are probably responsible for at least some of the destruction of connective tissue and bone that occurs. Classical antibody-mediated hypersensitivity reactions probably do not provide the reasons. Mechanisms are more likely to be found in the pro-inflammatory and tissue-degrading effects of cytokines released in host-protective, antigen-specific and polyclonal responses to oral bacterial constituents or products. Some evidence suggests that limitation of clinical destruction in localized early onset periodontitis (JP) may in part be a function of a protective antibody response which develops after an initial rapidly progressive infection. A relatively deficient immune responsiveness may allow progression to more severe and generalized disease (RPP). Suggestions are made for studies needed to confirm suspected pathogenetic mechanisms, approach resultant targeted therapies, and test hypotheses for contrasting roles of immune reactions in different clinical expressions of periodontitis.

Autoimmunity in periodontal disease

Periodontal disease in characterized by the loss of the normal supporting tissues of the teeth and a humoral and cellular immune response to bacterial antigen of dental plaque which accumulates at the dento-gingival junction. This review considers the evidence for the existence of an autoimmune component of the host immune response, the possible origin of such a response and the way in which such a host response may contribute to the changes observed in the periodontium in the disease.

IgG subclass-containing cells in the human large bowel of normal controls, non-IBD colitis, and ulcerative colitis

IgG subclass-containing cells in colonic mucosa were examined in three groups; 1) normal controls 2) cases of ulcerative colitis (UC) 3) cases of colitis excluding UC and Crohn's disease (non-IBD colitis) by indirect immunoperoxidase staining method using mouse anti-IgG subclass monoclonal antibodies. The numbers (and proportions) of IgG1, IgG2, IgG3, and IgG4-containing cells in normal colonic mucosa was 80 +/- 29/mm2 (44.6%), 44 +/- 21 (24.1%), 44 +/- 24 (23.7%), 13 +/- 10 (7.7%), respectively. The proportion of IgG subclass-containing cells in normal colonic mucosa was different from the known proportion of IgG subclass in serum. In UC, the numbers of all IgG subclasses-containing cells were significantly increased compared to controls and non-IBD colitis. However, only IgG1-containing cells were increased in proportion (50.3%) compared to normal controls. In non-IBD colitis, the numbers of IgG1- and IgG2-containing cells were increased compared to the controls, but the increases were less than UC, and there was no difference in the proportion of IgG subclass compared to normal controls. The differences in the numbers and in the proportions of IgG subclass-containing cells between UC and non-IBD colitis may reflect differences in the underlying disease process.

Langerhans cells in oral epithelium of chronically inflamed human gingivae

This study describes the histopathological features and the distribution of oral epithelial Langerhans cells in 19 gingival biopsies originating from an adult Tanzanian population characterized by very poor oral hygiene and severe gingival inflammation. Light-microscopically, all biopsies contained often large inflammatory connective tissue infiltrates, 6 of which predominantly contained plasma cells while the rest were dominated by lymphocytes. Seven specimens contained peculiar accumulations of round lymphoid and dendritic cells in the lower cell layers of the oral epithelium. These phenomena have not previously been demonstrated in human gingiva and deserve further attention in studies on the pathogenesis of periodontal diseases. Immuno-histochemical staining with OKT6, OKT4 and OKT8 antibodies showed markedly increased numbers of OKT6-positive cells in 7 specimens and clusters of OKT4- and OKT8-positive cells in the oral epithelium of 4 specimens. High numbers of OKT6-positive cells were not related to the presence of intra-epithelial, non-keratinocyte infiltrates or large connective tissue infiltrates. The variable numbers of oral epithelial Langerhans cells may therefore result from different bacterial antigens elucidating different responses or, alternatively, reflect different responses to similar plaque antigens penetrating the surface of the oral epithelium.

IgG subclasses in gingival crevicular fluid from active versus stable periodontal sites

Since IgG subclasses are common immunoglobulins associated with the periodontium and have different biological characteristics, these subclasses were measured in gingival crevicular fluid (GCF) from periodontally active (greater than or equal to 2 mm clinical attachment loss within three months of sample) versus clinically similar but stable or healthy sites. A sandwich enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies was performed to quantitate IgG subclass and albumin concentrations in serum and interproximal GCF samples from at least one each of the three disease categories from each of 20 periodontal maintenance patients. Although much variability existed among sites, mean IgG1 (p less than 0.05) and IgG4 (p less than 0.01) concentrations were higher in GCF from active periodontitis areas than stable sites, even though both had similar clinical characteristics. When IgG subclass concentrations were adjusted per mg albumin, both IgG1 and IgG4 levels in GCF from active sites were still significantly elevated over stable areas (p less than 0.05). Mean adjusted concentrations in GCF were generally greater than in serum, especially for IgG4 (active site GCF:serum = 24.2:1). GCF IgG4 concentrations may be useful as an indicator of the immunopathological changes which occur in active periodontitis.

The effect of treatment on IgG, IgA, IgM and alpha-2-macroglobulin in gingival crevicular fluid from patients with chronic adult periodontitis

With a technique for sampling, processing and analysis of gingival crevicular fluid (GCF) that allows multiple constituents to be analysed from a sample collected on a filter paper strip, we have examined IgG, IgA, IgM and alpha-2-macroglobulin (alpha 2M) in GCF from patients with chronic adult periodontitis. Clinical data and GCF were collected before and 3 months after root planing and scaling, and analysed to determine trends for the population. A statistically-significant decrease in the percentage of sites with bleeding on probing, erythema and supragingival plaque was observed 3 months after therapy. The mean amount of each glycoprotein in GCF decreased dramatically at 3 months. In contrast, the mean volume of GCF was virtually identical at the two evaluations. The IgG/IgA and IgG/IgM ratios in GCF were elevated when compared with human serum suggesting the preferential occurrence of IgG in GCF. Correlation of the four glycoproteins with GCF volume and with enzyme markers of the acute inflammatory response in GCF revealed a relationship between arylsulphatase (a lysosomal enzyme), fluid influx, and the passage of larger molecular-weight glycoproteins (alpha 2M, IgM) into the gingival crevice.

A comparison of the reactivity of Eubacterium species with localized and serum immunoglobulins from rapidly progressive and adult periodontitis patients

Immunoglobulins in sera and in supernatant fluids of explant cultures of diseased gingival tissues from 20 rapidly progressive and 20 adult periodontitis sites were tested by an ELISA assay for reactivity with typed strains of Eubacterium alactolyticum, E. brachy, E. limosum and E. nodatum. Immunoglobulins present in tissue culture fluids from both rapidly progressive and adult periodontitis samples reactive with E. brachy and E. nodatum were significantly greater (P less than 0.05) than those reactive with E. alactolyticum or E. limosum. The titers to E. brachy in tissue culture fluids from adult periodontitis were significantly greater (P less than 0.05) than those from rapidly progressive periodontitis; there was no difference in titers to the other three species. The only significant difference in serum titers was that sera from patients with rapidly progressive periodontitis had significantly greater reactivity to E. alactolyticum than did sera from adult periodontitis patients. These data indicate that immunoglobulins in the sera of rapidly progressive and adult periodontitis patients do not necessarily reflect the reactivity of localized immunoglobulins present in the diseased gingival tissue explant culture fluids from these patients.

Periodontal manifestations of the heritable Mac-1, LFA-1, deficiency syndrome. Clinical, histopathologic and molecular characteristics

The clinical, histopathologic and functional consequences of the genetic deficiency of leukocyte Mac-1, LFA-1 and p150,95 were assessed among three affected patients, heterozygotes and unaffected individuals among two generations of a single kindred. Longitudinal assessments of this family afforded the unique opportunity to characterize the natural history of severe periodontal manifestations associated with this disorder. Features uniformly observed among each patient included recurrent, necrotic soft tissue infections, impaired pus formation, delayed wound healing, constant granulocytosis, severe abnormalities of adhesion-dependent granulocyte functions and a profound deficiency (3%-6% of normal) of Mac-1 glycoproteins on granulocyte surfaces. Characteristic features of generalized prepubertal periodontitis including rapidly progressive alveolar bone loss affecting the primary and permanent dentitions (leading to premature tooth loss), recession, clefting and migration in association with intense gingival inflammation were uniformly observed. Biopsies of inflamed periodontal tissues in these individuals demonstrated dense infiltrates of mononuclear leukocytes but a striking absence of extravascular neutrophil granulocytes. Heterozygous family members demonstrated approximately half normal Mac-1 protein expression but no susceptibility to systemic infections and normal, adhesion-dependent leukocyte functions. Prepubescent heterozygotes demonstrated no periodontal manifestations but a 31-year-old heterozygous female exhibited clinical and radiographic features typical of postjuvenile periodontitis. The profound periodontal manifestations recognized in this clinical-pathologic model emphasize the physiologic importance of leukocyte adhesion reactions in defense of the periodontium and further suggest a possible pathologic role for Mac-1 proteins in other forms of early-onset periodontitis.

Possible mechanisms involved in the immunoregulation of chronic inflammatory periodontal disease

It is generally agreed that immunological mechanisms are involved in the pathogenesis of periodontal disease; however, regulation of these mechanisms has hitherto received scant attention. Regulatory networks exist at both a cellular and a molecular level. At the cellular level, the existence of helper (T4-positive) and suppressor (T8-positive) T lymphocytes, the expression of Class II major histocompatibility complex antigens, and the heterogeneity of macrophage subpopulations are central to an understanding of the regulatory mechanisms involved. It is only recently that studies of these separate components, in both humans and experimental animals, have begun to provide a basis for understanding the complex interactions occurring in periodontal disease. Studies using the human experimental gingivitis model have shown an immunoregulatory picture consistent with a controlled immunological reaction with an essentially normal T4:T8 ratio of 2.0. In contrast, studies utilizing cells extracted from adult periodontitis lesions have shown a reduced T4:T8 ratio (approximately 1.0) and an inability to respond in, or to stimulate, an autologous mixed lymphocyte reaction. Animal studies using athymic nude rats have supported the concept of a central role for T-cell control in periodontal disease and the possibility of an imbalance in this control with disease progression. These results are reviewed and areas of future research explored.

The autologous mixed lymphocyte reaction (AMLR) as a possible indicator of immunoregulation in chronic inflammatory periodontal disease

Immunoregulatory control at both a local and systemic level is likely to be an important factor in the control of chronic inflammatory periodontal disease, explaining, at least in part, the individual variations between patients as well as the cyclical nature of the disease process. The autologous mixed lymphocyte reaction (AMLR), which is due to the stimulation of T cells by autologous HLA-DR positive non-T cells in the absence of specific antigen, is thought to be an in vitro correlate of immunoregulation. It is possible therefore, that the AMLR may detect systemic immunoregulatory phenomena in chronic inflammatory periodontal disease and that aberrations in the AMLR may be a manifestation of the disease and in turn reflect disease activity. Recent evidence does in fact suggest that the peripheral blood AMLR may identify particular disease groups, provided age and time of peak responsiveness are taken into account and hence may have an epidemiological application. It remains to be determined, however, that when used in a longitudinal fashion, the AMLR does reflect individual disease activity. These results are reviewed and areas of future research discussed.

Gingivitis

Gingivitis is caused by substances derived from microbial plaque accumulating at or near the gingival sulcus; all other suspected local and systemic etiologic factors either enhance plaque accumulation or retention, or enhance the susceptibility of the gingival tissue to microbial attack. Microbial species specifically associated with gingival health include Streptococcus sanguis 1, S. D-7, and Fusobacterium naviforme. Bacteria involved in the etiology of gingivitis include specific species of Streptococcus, Fusobacterium, Actinomyces, Veillonella, and Treponema and possibly Bacteroides, Capnocytophaga, and Eikenella. Microbial colonization and participation is sequential, with the complexity of the associated flora increasing with time. The pathogenesis has been separated into the initial, early, and established stages, each with characteristic features. The initial lesion is an acute inflammation which can be induced experimentally by application of extracts of plaque bacteria to normal gingiva. The early lesion is characterized by a lymphoid cell infiltrate predominated by T lymphocytes, characteristic of lesions seen at sites of cell-mediated hypersensitivity reactions. The early lesion can be induced by application of purified contact antigens to the gingival tissues of previously sensitized animals. As the clinical condition worsens, the established lesion appears, predominated by B lymphocytes and plasma cells. Established lesions may remain stable for indefinite periods of time, they may revert, or they may progress. Periodontal destruction does not result from the conversion of a predominantly T cell to a predominantly B cell lesion as has been suggested, but rather from episodes of acute inflammation. Clinical manifestations of gingivitis are episodic phenomena characterized by discontinuous bursts of acute inflammation. Most lesions are transient or persistent but not progressive. Attachment loss may precede alveolar bone loss and may occur without the manifestations of a concurrent or a precursor gingivitis. On the other hand, the evidence indicates that a portion of gingivitis lesions can and does progress to periodontitis. Gingivitis and the periodontal microflora differ in children and adults. Clinical signs of gingivitis either do not appear as plaque accumulates, or they are greatly delayed in children, and the inflammatory infiltrate consists mostly of T lymphocytes. The conversion to a B cell lesion does not appear to occur. The evidence supports the conclusion that gingivitis is a disease, and that control and prevention is a worthwhile goal and a health benefit.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell populations associated with interdental gingival bleeding

The purpose of this study was to characterize the cell populations of the mid-interproximal gingival tissue related to the presence or absence of bleeding. 15 bleeding and 15 non-bleeding interproximal gingival biopsies were obtained from 30 patients and processed for light microscopic evaluation. Morphometric analysis of tissue components revealed that bleeding was associated with an inflammatory lesion located in the mid-interproximal connective tissue. The inflammatory infiltrate was dominated by mononuclear cells of the lymphocyte/macrophage/monocyte group, and the proportions of plasma cells and polymorphonuclear leukocytes were relatively small. The results of this study indicated that interproximal bleeding can be associated with an inflammatory infiltrate not dominated by plasma cells. The rôle of gingival bleeding in the diagnosis of periodontal disease activity is discussed.

The nature of the inflammatory infiltrates in childhood gingivitis, juvenile periodontitis and adult periodontitis: immunocytochemical studies using a monoclonal antibody to HLADr

Routinely fixed and processed gingival biopsies from childhood gingivitis, juvenile periodontitis and chronic adult periodontitis patients have been stained immunocytochemically with a monoclonal anti HLADr antibody to aid in the identification and quantification of cell types in the inflammatory infiltrates. Using immunoperoxidase staining and morphological criteria, 9 cell types were quantified in 30 patients. Lesions in the 3 groups were found to differ widely both in size and composition. In the small childhood gingivitis lesions, most cells were small lymphocytes, over half of which were HLADr positive, whereas in juvenile periodontitis biopsies, well over half the infiltrate was plasma cells. The chronic adult periodontitis samples showed greater variability in composition between these 2 extremes, perhaps reflecting differences in disease activity. These results suggest that, when disease is quiescent, the volume of inflamed gingival connective tissue is small and is dominated by B-small lymphocytes, whilst on activation, the lesion increases in size and much of the B-lymphocyte population is transformed to plasma cells. This view corroborates the results of other workers with regard to juvenile periodontitis, but suggests a different interpretation of the quiescent lesion of childhood gingivitis from that current in the literature.

Immunohistological identification of cell subsets in human gingiva after local treatment for gingivitis or periodontitis

The cellular infiltrate present in human diseased gingiva was analyzed in biopsies from 12 patients with gingivitis or periodontitis. The samples studied had been obtained in the course of surgery at inflammatory sites remaining after institution of periodontal treatment. Histological and immunological techniques were used to identify macrophages, B-cells, plasma-cells, T-cells and T cell subsets, as well as cells expressing class II HLA membrane antigens. T-cells appeared as the predominant population, but plasma-cells were also visualized in nearly all samples. Both OKT4+ and OKT8+ cells were seen in all cases, the latter being more numerous in periodontitis patients. Interdigitating-like cells were observed, positively labelled for class II antigens, as well as macrophages which were more numerous in periodontitis patients. These results suggest the participation of all components of the immune response in gingival disease, in a way resembling chronic recurrent inflammatory diseases.

Bacterial profiles of subgingival plaques in periodontitis

In this report over 400 subgingival plaque samples taken from over 110 patients were examined microscopically and culturally for 30 bacterial parameters. The patients could be placed into six disease categories based upon clinical criteria. The bacterial profile of each clinical category was generally distinctive of that category. Periodontal patients who had been successfully treated and maintained had plaques that were populated by significantly higher proportions of Streptococcus sanguis, Actinomyces viscosus, A. odontolyticus and S. mutans and significantly lower proportions of B. gingivalis and spirochetes compared to the five untreated disease categories. The spirochetes were the overwhelming microbial type in the plaques of adult periodontitis (AP) patients, averaging about 45% of the microscopic count. The bacteriological results could not distinguish between ADA Type III and IV periodontitis, suggesting that the same type of infection was occurring in an active site in any AP patient. The patients designated as early onset periodontitis (EOP) differed from the other patients by their relative youth and by their significantly higher proportions of Bacteroides gingivalis and/or B. intermedius. Two types of EOP were recognized in which the most diseased variant was characterized by having an average of 49% spirochetes in the plaque. Four localized juvenile periodontitis (LJP) patients were notable in not having detectable A. actinomycetemcomitans. The data indicate that the various types of periodontitis, with the possible exception of LJP are specific anaerobic infections involving spirochetes and to a lesser extent B. gingivalis and B. intermedius.

Biochemical and immunobiological properties of lipopolysaccharide (LPS) from Bacteroides gingivalis and comparison with LPS from Escherichia coli

Lipopolysaccharides (LPSs) were isolated from Bacteroides gingivalis and Escherichia coli by the phenol-water and butanol-water procedures. The phenol-water-extracted LPS from B. gingivalis 381 was composed of 46% carbohydrate, 23% hexosamine, 18% fatty acid, and 5% protein. The major component sugars of this preparation were glucose, glucosamine, rhamnose, galactose, galactosamine, and mannose, and their molecular ratio was 1:0.9:0.7:0.6:0.6:0.4, respectively. Neither heptose nor 2-keto-3-deoxyoctonate was detected. The butanol-water-extracted LPS from this strain was composed of 76% glucose, 7% fatty acid, and 13% protein, and it was associated with a number of polypeptides (13 to 56 kilodaltons). The main fatty acid of both LPS preparations was palmitic acid. It was found that biological activities of LPS from B. gingivalis were comparable to those of LPS from E. coli in terms of activation of the clotting enzyme of Limulus amebocyte lysate, mitogenicity, polyclonal B cell activation, and stimulation of interleukin 1 production in BALB/c mice. Furthermore, LPS-nonresponsive C3H/HeJ spleen cells were found to yield good mitogenic responses to both phenol-water-extracted LPS and butanol-water-extracted LPS from B. gingivalis or butanol-water-extracted LPS from E. coli. On the other hand, spleen cells from LPS-responsive C3H/HeN mice responded well to all these LPS preparations.

Dextran-induced inflammation and its effect on keratinized gingival epithelium in monkeys

The cell population present during dextran-induced inflammation and its effect upon induced keratinization of the sulcular epithelium was investigated in two young adult male Rhesus monkeys. Keratinization of the sulcus epithelium was induced by a combined regimen of scaling, an intravenous injection of achromycin and daily rubber cup prophylaxes. After keratinization was confirmed by means of biopsies, inflammation was induced either by injecting 200 microliters of a 5% dextran saline solution or by applying the solution topically on the marginal gingiva for 2 weeks. Clinical grade dextran, molecular weight 70,000, was used. Physiologic saline solution, either injected or topical, was also used. At the same time, the daily prophylaxes were continued. After the 2 weeks, gingival biopsies were taken from each tooth treated with the different regimens. One-half of each biopsy was routinely processed and stained with hematoxylin and eosin or Rhodamine B, while the other half was processed for and stained with alcoholic and aqueous PAS to detect dextran in tissues. Histologic evaluation was carried out in three areas: a crestal zone, a cervical zone and an oral gingival zone. An Inflammatory Index (II) was determined and the width and length of keratin were measured. Dextran, either topical or injected, produced mainly a chronic inflammatory response characterized by lymphocytes (30-35%), monocytes-macrophages (5-10%), plasma cells (10%), polymorphonuclear leukocytes (PMNs) (15%) and unidentified cells (35%). Conversely, the physiologic saline-induced inflammation showed PMNs (75%), lymphocytes (5%) and unidentified cells (20%). The II for injected areas was significantly higher than for those topically treated or for nontreated controls. However, the increased II did not affect the degree of keratinization achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Parotid saliva agglutinins for sheep erythrocytes as a measure of ongoing inflammation in periodontal disease

The level of parotid saliva agglutinins to sheep erythrocytes (PSAE) may be directly related to the severity of ongoing inflammation. PSAE were titrated in a population of 19 individuals with no clinical evidence of gingivitis or periodontitis. In these normal individuals PSAE were detected at an average salivary dilution of 1:8. However, 31 patients receiving treatment for periodontitis had PSAE at an average dilution of 1:26. Furthermore, the parotid saliva of those periodontal patients had significantly higher IgA and protein concentrations than the healthy group. The salivary flow rate and the IgA to protein ratio were similar in both groups. The elevated titer of PSAE may be due in part to heterogenic stimulation of B cells in periodontal tissues and therefore may be related to the rate of the ongoing inflammatory disease process.

Ultrastructural localization of acid phosphatase activity in plasma cells containing Russell's bodies in periodontitis

Acid phosphatase activity was examined ultracytochemically in gingival specimens to elucidate the response of plasma cells to Russell's bodies. The acid phosphatase activity was discernible in lysosomes of various morphology, some of which contained Russell's bodies. The acid phosphatase activity was stronger in the peripheries of such lysosomes, but weak activity was also found inside Russell's bodies. These findings indicated that at least some of Russell's bodies formed within the plasma cells were degraded in autophagolysosomes.