The distribution of HLA-A and -B antigens in patients and their families with periodontosis

A case-control study on the association of human leukocyte antigen-A*9 and -B*15 alleles with generalized aggressive periodontitis in an Indian population

BACKGROUND

The genes encoding the human leukocyte antigens (HLAs; major histocompatibility complex [MHC]) have been considered candidate markers for periodontitis because they are involved in regulating immune responses. Several studies have examined this association, and despite the inconclusive results, the antigens HLA-A9 and HLA-B15 have been found to be consistently associated with the destructive forms of periodontitis in many populations. Ethnic factors are considered to be a major variable for evaluating the predisposition to the disease. The purpose of the present study was to: 1) assess the association of HLA-A*9 and HLA-B*15 with generalized aggressive periodontitis (GAgP) and 2) evaluate the role of these genetic risk factors in influencing the severity of GAgP in a South Indian population.

METHODS

Forty GAgP patients (cases) and 80 periodontally and systemically healthy subjects (controls) participated in this study. HLA-A*9 and HLA-B*15 typing was carried out using the polymerase chain reaction with sequence specific primers (PCR-SSP)-based molecular method.

RESULTS

HLA-B*15 was a significant risk factor for GAgP and was positively correlated with the disease severity, whereas HLA-A*9 had no association with the disease. The haplotype of HLA-A*9:B*15 did not impart any additional risk for GAgP compared to that imparted by HLA-B*15 alone.

CONCLUSIONS

To our knowledge, this is the first report on HLA-B*15 association with GAgP in an Indian population. The finding of HLA-B*15 as a risk factor may have potential use in the future management of GAgP. The precise disease-causing mechanism of this HLA disease association and whether this association is "causal" or "casual" need to be evaluated further.

Inter-relationships between rheumatoid arthritis and periodontal disease. A review

This review considers the considerable similarities between periodontal disease and rheumatoid arthritis (RA). While the etiology of these two diseases may differ, the underlying pathogenic mechanisms are remarkably similar and it is possible that individuals manifesting both periodontitis and RA may suffer from a unifying underlying systemic dysregulation of the inflammatory response. In light of these findings, the implications for the use of disease-modifying medications in the management of these two chronic inflammatory conditions is apparent. Further longitudinal studies and medication-based intervention studies are required to determine just how closely these two conditions are allied.

Periodontal attachment loss in HIV-infected patients is associated with the major histocompatibility complex 8.1 haplotype (HLA-A1,B8,DR3)

Periodontal attachment loss is mediated by overproduction of tumour necrosis factor (TNF) and interleukin (IL)-1, and appears to have a genetic component. The 8.1 major histocompatibility complex (MHC) ancestral haplotype (HLA-A1,B8,TNFA-308(2),DR3) is associated with elevated TNF production and predisposes carriers to several autoimmune/immunopathological disorders, including rapid progression of HIV disease, but not early onset periodontal disease in healthy individuals. Rather a high proportion of subjects with severe periodontal disease carry allele 2 at IL-1A-889 and IL-1B+3953. We predicted that genetic associations may be different or clearer in HIV patients, as they often show elevated production of TNF and IL-1 and periodontal attachment loss. Hence periodontal parameters and IL-1 polymorphisms were assessed in HIV-positive subjects expressing HLA-B8 with or without other markers of the 8.1 haplotype. Of 16 HLA-B8 subjects, 13 demonstrated elevated probing pocket depth and clinical attachment loss. The difference was statistically significant and did not correlate with smoking, age, CD4 T-cell counts, HIV viral load or levels of dental plaque. As TNFA-308 (allele 2) was present in four non-B8 subjects who had minimal attachment loss, it may not mediate the effect of the 8.1 haplotype. Moreover, polymorphisms at IL-1A-889 and IL-1B+3953 did not significantly affect periodontal parameters. Thus a central MHC gene characteristic of the 8.1 haplotype was the clearest determinant of periodontal attachment loss in HIV-infected individuals.

HLA genetics for diagnosis of susceptibility to early-onset periodontitis

Human leukocyte antigens (HLA) are essential in the recognition of foreign antigens in humoral immune response, which is genetically predetermined. Susceptibility to certain diseases that involve the immune response has been studied in relation to distinct HLA types. Although some diseases have been found to correlate to specific HLA loci positively, it has been difficult to isolate HLA types that predispose patients to periodontal destruction. Here, we review the current knowledge and recent advances in HLA genetics and its biology, which determine susceptibility to early-onset periodontitis (EOP). The HLA-DRB1*1501-DQB1*0602 genotype has been found with increasing frequency in EOP patients. This HLA genotype expresses aspartic acid at position 57 and glycine at position 70 on the DQ beta chain, suggesting a capability to bind certain bacterial antigens. The T cell response against the outer membrane protein (Ag53) of Porphyromonas gingivalis was examined via this HLA genotype. Strong T cell response against Ag53 p141-161 was inhibited partially by anti-DR antibody, but not by anti-DQ antibody. Possible host and bacterial peptides capable of binding DRB1*1501 were elucidated when the peptide sequence was compared to gene and protein databases. These results suggest that patients who have the HLA-DRB1*1501-DQB1*0602 genotype may have an accelerated T cell response to certain periodontopathic bacteria such as P. gingivalis in hyperimmune reactions and thus increased susceptibility to EOP.

Genetic aspects of dental disorders

This paper reviews past and present applications of quantitative and molecular genetics to dental disorders. Examples are given relating to craniofacial development (including malocclusion), oral supporting tissues (including periodontal diseases) and dental hard tissues (including defects of enamel and dentine as well as dental caries). Future developments and applications to clinical dentistry are discussed. Early investigations confirmed genetic bases to dental caries, periodontal diseases and malocclusion, but research findings have had little impact on clinical practice. The complex multifactorial aetiologies of these conditions, together with methodological problems, have limited progress until recently. Present studies are clarifying previously unrecognized genetic and phenotypic heterogeneities and attempting to unravel the complex interactions between genes and environment by applying new statistical modelling approaches to twin and family data. Linkage studies using highly polymorphic DNA markers are providing a means of locating candidate genes, including quantitative trait loci (QTL). In future, as knowledge increases; it should be possible to implement preventive strategies for those genetically-predisposed individuals who are identified to be at risk.

HLA Class II genotypes associated with early-onset periodontitis: DQB1 molecule primarily confers susceptibility to the disease

DNA typing was performed on 24 Japanese patients with early-onset periodontitis (EOP) using the PCR-RFLP method to investigate an association of the susceptibility to EOP with the particular HLA class II alleles (HLA-DRB1, -DQA1, and -DQB1). DRB1*1401, DRB1*1501, DQB1*0503, and DQB1*0602 were found more frequently ("susceptible") in the EOP patients than in healthy controls. In contrast, DRB1*0405 and DQB1*0401 were found less frequently ("resistant") in EOP patients. All patients carrying DQB1*0602 had an atypical BamHI site in the intron upstream of the third exon of the DQB1 gene, which in our previous studies appeared to be a susceptible marker for EOP. A comparative analysis of the amino acid sequences of these susceptible and resistant HLA-DRB1 and DQB1 alleles elucidated some differences in antigen-derived peptide binding sites related to the susceptible or resistant alleles. Especially, DQB1*0503 and DQB1*0602 alleles carrying aspartic acid at position 57 and glycine at position 70 are increased significantly in EOP. Since amino acid residues at positions 57 and 70 on the DQB1 molecule are supposed to be involved in antigen binding, amino acid substitutions at these positions may affect the immune responsiveness to the periodontopathic antigen. Our results suggest that the DQB1 molecule plays a crucial role in the pathogenesis of EOP and that the susceptibility to EOP may be determined by the binding ability between the peptide and HLA-DQ antigens.

Association between HLA antigens and early onset periodontitis

HLA-A, B, C and DR antigen frequencies were determined in a group of patients with juvenile periodontitis and rapidly progressive periodontitis. In juvenile periodontitis patients, HLA-A24 and DR4 were found at a significantly higher level than in the control group, and in rapidly progressive periodontitis patients, A9 and DR4 were found at a significantly higher level than the control group. The presence of these antigens gives evidence as to the susceptibility of various forms of early onset periodontitis.

Host defensive functions in a family manifesting early-onset periodontitis

Family case studies help us identify host risk factors in periodontal disease. In this study we examine a family consisting of a mother (40 years old, with rapidly progressive periodontitis), her elder daughter (14 years old, with localized juvenile periodontitis), and younger daughter (13 years old, with simple gingivitis). We examined 1) the peripheral neutrophil functions (chemotactic migration, phagocytosis, superoxide production); 2) lymphocyte functions (proliferative activity and cytokine productivity of T cells, immunoglobulin [Ig] M productivity of B cells when stimulated with pokeweed mitogen); 3) phenotypic analyses of peripheral lymphocyte subpopulations; 4) serum IgG antibody titers against periodontopathic bacteria; and 5) serological type of HLA class II. All the subjects exhibited high T4/T8 ratios due to high percentage of CD4-positive cells, showed high IgG titers to Actinobacillus actinomycetemcomitans, and had a HLA DQw1 in common. The mother showed a slight deficiency of neutrophil chemotactic migration to N-formyl methyonyl leucyl phenylalanin (fMLP), raised interleukin-2 productivity of T cell, and high levels of IgG titers to Porphyromonus gingivalis and Fusobacterium nucleatum. Both daughters showed weak T cell proliferative response to anti-CD3 monoclonal antibody and low IgM productivity. Low lymphocyte responsiveness may be involved in the pathogenesis of periodontal disease of these daughters; therefore, the lymphocyte dysfunctions shown should be considered in relation to the progression of periodontal disease.

Immunological, genetic, and microbiological study of family members manifesting early-onset periodontitis

From the standpoint of host-parasite interactions, family studies help us understand the host defensive factors and the molecular mechanisms involved in the periodontal immune response. In this study, we report the immunological profile of host-defensive functions, human leukocyte antigen (HLA) phenotypes, and the microflora of a mother (rapidly progressive periodontitis), an older son (periodontally healthy), a younger son (localized juvenile periodontitis), and a daughter (localized juvenile periodontitis). We examined the peripheral neutrophil functions, phenotypic and functional analysis of peripheral lymphocytes, serum immunoglobulin G (IgG) antibody titers against periodontopathic bacteria, serological type of HLA class II antigens, and bacterial flora in all periodontal pockets. The results showed that Actinobacillus actinomycetemcomitans was dominant in the pockets of all subjects. The mother and two sons showed a depressed neutrophil chemotaxis to N-formyl-methionyl-leucyl-phenylalanine. All subjects except the older son exhibited low T4/T8 ratios. The mother and daughter had raised levels of IgG titers to Porphyromonas gingivalis. All subjects had HLA phenotypes of DRw52 and DQ1 in common. We found that the family members had similar disorders in certain defensive functions. This family has been a model for our understanding of the host defensive factors in the development of early-onset periodontitis.

Genetic influences in caries and periodontal diseases

Deciphering the relative roles of heredity and environmental factors ("nature vs. nurture") in the pathogenesis of dental caries and diseases of the periodontium has occupied clinical and basic researchers for decades. Success in the endeavor has come more easily in the case of caries; the complex interactions that occur between host-response mechanisms and putative microbiologic pathogens in periodontal disease have made elucidation of genetic factors in disease susceptibility more difficult. In addition, during the 30-year period between 1958 and 1987, only meager resources were targeted toward the "nature" side of the nature/nurture dipole in periodontology. In this article, we present a brief history of the development of genetic epistemology, then describe the three main research mechanisms by which questions about the hereditary component of diseases in humans can be addressed. A critical discussion of the evidence for a hereditary component in caries susceptibility is next presented, also from a historical perspective. The evolution of knowledge concerning possible genetic ("endogenous", "idiotypic") factors in the pathogenesis of inflammatory periodontal disease is initiated with an analysis of some foreign-language (primarily German) literature that is likely to be unfamiliar to the reader. We identify a turning point at about 1960, when the periodontal research community turned away from genetics in favor of microbiology research. During the past five years, investigators have re-initiated the search for the hereditary component in susceptibility to common adult periodontal disease; this small but growing body of literature is reviewed. Recent applications of in vitro methods for genetic analyses in periodontal research are presented, with an eye toward a future in which persons who are at risk--genetically predisposed--to periodontal disease may be identified and targeted for interventive strategies. Critical is the realization that genes and environment do not act independently of each other; the appearance or magnitude of heritability may differ with various environments.

Genetic and heritable risk factors in periodontal disease

The purpose of this paper is to review current knowledge of genetic risk factors for the periodontal diseases and to present updated and additional data from the Minnesota Twin Periodontal Study. Family studies suggest that susceptibility to the early onset forms of disease, particularly prepubertal and juvenile periodontitis, is, at least in part, influenced by host genotype. Inherited phagocytic cell deficiencies appear to confer risk for prepubertal periodontitis. The prevalence and distribution of juvenile periodontitis in affected families are most consistent with an autosomal recessive mode of inheritance. However, considerable etiologic as well as genetic heterogeneity within these clinically-defined diseases is evident. Whether or not genetic factors influence the more common adult chronic periodontitis is less clear. Although results from family studies suggest that environmental factors appear to be the major determinants of variance in adult periodontitis, data from our twin studies indicate that both genetic and environmental factors influence disease. Furthermore, comparisons between reared-together and reared-apart adult monozygous twins indicate that early family environment has no appreciable influence on probing depth and attachment loss measures in adults.

Unique intronic variations of HLA-DQ beta gene in early-onset periodontitis

Human leukocyte antigen (HLA) class II beta chain plays an important role in the recognition of foreign antigens in immune reactions. Different forms of immune reaction may be concerned with initiation and progression of infectious diseases such as periodontitis. In this study we examined the frequency of HLA class II serotype and the variation of HLA class II beta gene in periodontitis patients. HLA serotypic frequencies in 70 Japanese patients with periodontitis and 26 individuals with periodontal health were examined. No HLA serotype specific to any type of periodontitis was observed. In order to detect differences among some HLA serotypes, restriction fragment length polymorphism (RFLP) analysis was undertaken with cDNA probes for HLA-DR beta and HLA-DQ beta genes in 20 subjects (15 patients and 5 healthy individuals). Atypical BamHI and EcoRI restriction sites were found in the HLA-DQ beta gene from 3 patients with early-onset periodontitis. In addition to these 20 subjects, an additional 80 subjects (40 patients and 40 healthy individuals) were screened for the atypical BamHI restriction site using the polymerase chain reaction method. It was detected in 7 patients with early-onset periodontitis, 1 patient with adult periodontitis, and 3 healthy subjects. No clinical differences except age were found between patients with this gene variation and other patients. Interestingly, all 3 healthy subjects with this gene variation were from subjects whose family members developed early-onset periodontitis with the gene variation. Atypical BamHI and EcoRI restriction sites and 41-nt repeated sequence were found in the intron before the third exon of HLA-DQB gene. These results suggest that these intronic gene variations may be useful as gene markers for a subpopulation of early-onset periodontitis and might affect immune reactions such as antigen recognition.

HLA A9 and B15 are associated with the generalized form, but not the localized form, of early-onset periodontal diseases

HLA proteins are genetically determined, and account in part for individual immune response. Several studies have been performed seeking an association between HLA antigens and various forms of periodontitis with no conclusive results. The aim of the present study was to determine the frequency of HLA antigens of patients suffering from the localized (LJP) and the generalized (SGP) forms of early-onset periodontitis (EOP). Twenty-six EOP patients from the same ethnic group were studied in comparison to 113 race-matched controls. The EOP group included 11 LJP and 15 SGP patients. HLA-A9 and B15 antigens were found to be significantly elevated in the patient group. These differences were found to be due to the high frequency of A9 and B15 antigens in the SGP patients, with the LJP patient group showing no significant difference from the control group. The results are in agreement with previous studies in which A9 and B15 were found to be associated with EOP. However, previous studies did not differentiate between the localized and the generalized form of EOP. These results support the hypothesis that the generalized and the localized forms of EOP are under different genetic control.

Destructive periodontal disease in healthy children

This study determined the prevalence of destructive periodontal disease affecting the deciduous dentition among otherwise healthy subjects, who were diagnosed with juvenile periodontitis (JP) in their permanent dentitions. There were 4,757 subjects in this retrospective, cross-sectional study. Diagnosis of JP was based on age (< or = 15 years), negative medical history, and radiographic evidence of arc-shaped alveolar bone loss. The study population was one-third white and two-thirds black and the male/female ratio was 1:1, reflecting the general patient population. The prevalence among whites was 0.3%, with a female/male ratio 4:1; whereas among blacks the prevalence was 1.5%, with a female/male ratio approximately 1:1. Among the black JP subjects with radiographs of the mixed dentition, 85.7% presented evidence of bone loss, and of those with radiographs of the deciduous dentition, 71.4% had discernible alveolar bone loss. This study suggests that JP is much more prevalent in blacks and that it does indeed occur in the prepubertal years affecting the deciduous as well as the permanent dentitions in otherwise healthy children. These data imply the importance of including a periodontal evaluation in the examination of children, using the periodontal probe and radiographs sufficient to adequately view the alveolar bone.

Genetic approaches in the study of periodontal diseases

Periodontal diseases are essentially infectious in origin, their outcome depending on interaction between the pathogenic challenge and host response. Host genotype has been implicated in certain of the more unusual forms, but together these account for only a small proportion of periodontal patients. Nevertheless, the genes for these rarer conditions, some of which have already been located and/or cloned, are of considerable importance, since they may ultimately provide clues leading to a better understanding of the whole spectrum of periodontal disease. For the majority of periodontal patients, although inherited susceptibility is suspected, evidence of a significant genetic component is scanty. The priority here is therefore to establish the existence of contributing genes. This may be possible by using approaches designed to minimise the confounding effect of environmental variation that has probably been a source of confusion in the past.

Some immunological findings in adult periodontitis

There is little doubt that immunological mechanisms play an important role in chronic inflammatory periodontal disease. At the same time, it is recognized that patient susceptibility is ultimately responsible for the clinical manifestation of the disease. In this context, the present study was undertaken to examine a range of systemic immunological parameters in patients with adult periodontitis (AP), so as to test the hypothesis that a specific pattern would identify diseased--possibly 'at risk'--patients. These parameters included serum IgA, IgG, IgM, IgD, C3, transferrin, the presence of circulating immune complexes, and the number of circulating T (E-rosette forming) cells. One hundred and forty AP patients and 70 healthy controls were examined. Following a complex statistical analysis only the levels of IgG, IgM and IgD were significantly increased in adult periodontitis (p less than 0.05) while an increase in circulatory immune complexes was significant only for separate statistical tests. Although statistically different, the levels seen in AP patients were still within the normal range hence the clinical significance of the findings is such that it is unlikely that these systemic immunological parameters per se do define an 'at risk' population.

Peripheral T lymphocyte subsets in rapidly progressive periodontitis

The peripheral blood lymphocyte subsets of 10 patients with rapidly progressive periodontitis were investigated with monoclonal antibody. In 4 patients, the T helper/T suppressor ratio was increased. 5 others had a slightly reduced T helper/T suppressor ratio as compared to control group. These findings may indicate a possible cellular immune response in the pathogenesis of rapidly progressive periodontitis.

Association between HLA antigens and periodontal disease

HLA-A, B and DR antigen frequencies were determined in three groups of periodontally diagnosed subjects: 49 patients with rapidly progressive periodontitis, 40 elderly subjects with minimal disease (considered as a resistant group) and 30 young subjects with minimal disease. The relative risk for HLA-A9 (previously reported to be associated with periodontal disease) was 15.5. HLA-A9 was present in 36.7% of the patients and 2.5% of the resistant group. HLA-A10 showed a significantly increased incidence in the resistant group (30.0%) compared to a non-periodontally diagnosed control population (9.0%), and was absent from the patient group. These findings provide additional evidence for the involvement of HLA-A9 in susceptibility to periodontitis, and suggest that A10 may play a role in resistance to the disease.

Experimental gingivitis in relation to age in individuals not susceptible to periodontal destruction

The purpose of the present investigation was to study the effect of age on the rate of development of gingival inflammation in individuals not susceptible to periodontal destruction. 7 younger (mean age 37 years) and 7 older (mean age 58 years) individuals were selected on the basis of the presence of at least 18 teeth, no evidence of extraction due to periodontal destruction, no loss of attachment, shallow pockets, gross amounts of plaque and a history of no interdental cleaning. All individuals were subjected to a carefully controlled oral hygiene program and experimental gingivitis was induced in 1 quadrant of the mouth during a period of 33 days. The amount of plaque, redness and swelling of the gingiva, and bleeding on probing were assessed before, during and after the experiment. At day 33, supra-gingival plaque samples were taken for bacteriological examination and gingival biopsies were taken for histopathological and immunohistochemical investigation. Results showed no differences between the 2 age groups with regard to the amount of plaque accumulation and the rate of development of gingival inflammation. Furthermore phase-contrast microscopy of plaque samples showed no differences between the 2 age groups. Neither histological nor immunohistochemical investigation showed any differences between the 2 age groups. All biopsies diffusely showed presence of IgG, whereas in most biopsies, IgA plasma cells and in one biopsy IgM plasma cells were found. Neither IgD, IgE nor complement deposits were found. It was concluded that age is of minor importance in the development of experimentally-induced gingivitis in individuals not susceptible to periodontal destruction.

1985 Kreshover lecture. Molecular factors influencing neutrophil defects in periodontal disease

Major advances in our understanding of the role of the neutrophil in host defense against periodontal organisms have been made through studies of localized juvenile periodontitis (LJP). Several lines of evidence suggest that LJP is an infectious process closely associated with Actinobacillus (Haemophilus) actinomycetemomitans as a causative agent, although other organisms may also participate. The immunologic profile of LJP patients suggests that a cell-associated neutrophil locomotory dysfunction is a key underlying immunodeficiency resulting in increased susceptibility to periodontal infection. In addition, LJP patients often exhibit cervical lymphadenopathy and IgG-hypergammaglobulinemia, and a markedly elevated antibody response to the infecting organism, A. actinomycetemcomitans, is found in the serum and crevicular fluid of most patients. Evaluation of the locomotory properties of LJP neutrophils shows that random migration and chemokinesis are normal; however, about 70% of the LJP patients suffer from a defect in chemotaxis, with their neutrophils responding poorly to bacterial chemotactic factors, synthetic chemotactic peptides, and complement fragments (C5a). Depressed chemotaxis of LJP neutrophils is paralleled by their reduced capacity to bind the synthetic chemotactic peptide N-formylmethionylleucylphenylalanine (FMLP), as well as C5a. Furthermore, there is a reduction in the amount of glycoprotein 110, a neutrophil membrane matrix component and differentiation antigen which is associated with FMLP- and possibly also C5a-mediated chemotaxis. Reduction of C5a and of FMLP ligand binding, decreased expression of GP-110, and reduced neutrophil chemotaxis are consistent with a stem cell maturation error in LJP patients. This is further supported by studies demonstrating increased expression of CR2, the C3d/EBV receptor, on peripheral blood neutrophils of LJP patients. CR2 receptors are normally present on immature human neutrophils but are lost during the maturation process. These alterations in neutrophil surface components and their reduced chemotaxis may result from a genetically determined abnormality. Studies demonstrating the familial nature of both the neutrophil chemotactic disorder and the clinical entity represented by localized juvenile periodontitis point to a strong role for genetic determinants in the disease which affect neutrophil surface receptors.

Association between HLA-A9 and rapidly progressive periodontitis

HLA-A, B, C, DR antigen frequencies and Properdin factor B (Bf) allotypes were studied in a group of 44 patients with rapidly progressive periodontitis. HLA-A9 (A24) was the only antigen with a frequency statistically significantly different from the control population. An increased frequency of HLA-A9 was previously reported in periodontal diseases. Our results in a well characterised group of patients adds to the evidence that HLA-A9 plays a role in the susceptibility to severe periodontitis.

Host factors in juvenile periodontitis

This study was undertaken to determine whether defects in leukocyte function or in genes at the MHC play a role in the etiology of either localized (LJP) or generalized (GJP) juvenile periodontitis. Thirteen LJP and five GJP patients (ranging in age from 13 to 22 years) and their matched controls were compared with respect to selected leukocyte functions and HLA phenotypic frequencies. The results of these studies indicated that there were significant decreases in the phagocytic and chemotactic abilities of polymorphonuclear leukocytes (PMN) in both LJP and GJP. All JP patients displayed intrinsic cell defects in chemotaxis compared with controls; in addition, some patients displayed multiple defects, including those which were serum-associated. Also, there appeared to be a significant association between JP and HLA-DR2 and HLA-A33 phenotypes. Fifty percent of the JP patients were HLA-DR2-positive, whereas only six percent of the matched controls were positive. Thirty-six percent of JP patients were HLA-A33-positive, whereas none of the controls was positive. The association seen with DR2 may be due to sampling, since there were no significant differences between the JP cases and a larger unmatched control sample which was not evaluated for periodontal disease. We conclude from these data that increased susceptibility of some patients to a very aggressive and destructive form of periodontal disease (JP) is based on defects in PMN responsiveness. Further investigations are necessary to determine whether these defects are under genetic control.

The cellular host response in juvenile periodontitis. A review

The current knowledge on the cellular, host-response features in juvenile periodontitis (JP) has been reviewed. The chemotaxis of the polymorphonuclear leukocytes (PMNs), known to be defective in JP, is modulated by serum factors and bacteria. The interactions of the putative etiologic pathogen Actinobacillus actinomycetemcomitans (A.a.) and the enzyme lysozyme with PMNs modify the host defense. Data on the phagocytic capacity of the peripheral blood and gingival crevice PMNs in JP are still controversial. The monocytes exhibit similar alterations as PMNs in interaction with A.a., but the reports on defective monocyte chemotaxis are conflicting. Both bacterial challenge and genetic factors may regulate the lymphocyte response in JP.

Clinical studies of one family manifesting rapidly progressive, juvenile and prepubertal periodontitis

We report clinical, radiographic and historical data on a large family with an unusually high prevalence of periodontitis. The proband, a 20-year-old black male, had the classic features of juvenile periodontitis (JP). His father was periodontally normal, while his mother had lost all her teeth at age 27 because of rapidly progressive periodontitis (RP). In addition to the 13 living children the couple had had 2 miscarriages. Of the children, one had RP, five had JP and two had prepubertal periodontitis (PP). Both maternal grandparents of the proband had become edentulous at an early age, presumably because of early-onset periodontitis. Four of 10 siblings of the proband's mother had early-onset periodontitis. In contrast, the paternal grandparents did not have early-onset periodontitis nor was periodontitis unusually prevalent in the siblings of the proband's father. The pedigree for this family is consistent with, but does not prove, an X-linked dominant pattern of genetic transmission. The natural history of early-onset periodontitis and the relationship among PP, JP and RP are not understood. The fact that the mother of the proband had RP and she had offspring with RP, JP and PP indicates a close relationship among these diseases and argues in favor of a common underlying mechanism. JP was not preceded by PP in the proband nor his affected 21-year-old brother, but one sister had PP, and at age 15 manifested JP. In her case, the alveolar bone around the deciduous molars had been destroyed, but it regenerated as the permanent premolars erupted.(ABSTRACT TRUNCATED AT 250 WORDS)

Human lymphocyte antigen haplotype and resistance to periodontitis

Certain human lymphocyte antigen (HLA) haplotypes have been correlated with the presence of certain diseases. To date no significant relationship between periodontitis and HLA haplotype has been demonstrated. The purpose of this study was to determine the frequency of HLA-A, HLA-B and HLA-C haplotypes in patients resistant to chronic periodontitis and to determine if there is any association between specific HLA genes and periodontal health. Twenty-five healthy individuals who demonstrated a high resistance to periodontal disease (mean age 49.9 years) were matched to 25 subjects with chronic periodontitis and to a periodontally undiagnosed population of 22,000 individuals. Peripheral blood was taken and HLA specificity was determined by the microlymphocytotoxicity test. The results indicated a statistically significant increase in the occurrence of HLA-B5 (P = 0.0059) and a trend in the occurrence of HLA-A28 (P = 0.0565) in those patients resistant to periodontal disease when compared to the matched controls. When compared to the large random control group, a significant correlation was observed for HLA-A28 (P less than 0.01) in blacks and HLA-B5 (P less than 0.01) in whites. It is possible that the HLA-A28 and the HLA-B5 individual may have the ability to resist the progression of chronic periodontitis.

Clinical, microbiological and immunological studies of a family with a high prevalence of early-onset periodontitis

Extensive clinical, laboratory and microbiological studies were performed on members of a family with an unusually high prevalence of early-onset severe periodontitis. Clinical observations included intraoral photographs and assessment of inflammation, plaque, probing depths and bone loss. Pocket bacteria were sampled, cultivated and identified. Immunological studies included assessment in vitro of neutrophil (PMN) and monocyte (MN) chemotaxis, assessment of PMN phagocytosis and other functions using the iodination assay, measurement of serum opsonic and chemoattractant activities and determination of levels of serum antibodies specific to various putative periodontal pathogens. The proband, a 19-year-old white woman, had rapidly progressive periodontitis (RP). Of her six siblings available for study, all had juvenile periodontitis (JP), and both parents had been edentulous since early adulthood. Early edentulism and recurrent infections, especially otitis media, were prevalent in the forebearers, especially on the maternal side. Two married sisters of the proband had young male children with recurrent infections. Abnormalities in leukocyte chemotaxis were found in the proband, in two of her siblings and in both parents. The pocket flora was predominantly Gram-negative, anaerobic rods with a high prevalence of Bacteroides species, and serum antibodies specific to Bacteroides species were detected in the sera of five of the seven patients studied. Actinobacillus actinomycetemcomitans was not found in any of the pockets studied, nor were antibodies specific to any of the three known serotypes of this bacterium detected in the serum of any of the patients. There was a relatively good correlation between the bacterial species isolated from the periodontal pockets and the antibodies found in the serum. PMN iodination and serum opsonic activity were normal in all of the patients. Thus not all JP patients have detectable Actinobacillus species in their periodontal pockets, nor do all have antibody detectable with the techniques we used specific to these bacteria in their serum. In contrast, JP patients may have Bacteroides species in their periodontal pockets and antibody specific to Bacteroides species in their serum. Although abnormal leukocyte chemotaxis is generally common in RP and JP patients, in this family the correlation between this defect and the presence of these diseases was poor.

HLA and disease

This review describes the greater portion of a large number of new studies on HLA and disease association which has appeared in the literature since 1979. The majority of these are concerned with the association of certain diseases with class II major histocompatibility complex antigens. The possible biologic significance of these associations in terms of their probable etiology appears to be the prevailing theme. Current thinking regarding certain heritable diseases is described. It seems that although much has been done to resolve the genetics of insulin-dependent diabetes mellitus, other diseases such a multiple sclerosis still remain a mystery. Doubtlessly, much will be gained from DNA cloning and sequencing studies proposed for the future. A great deal of new information has been obtained relative to HLA itself. New loci have been postulated in the HLA-D/DR region through the use of powerful immunochemical procedures made possibly by the advent of modern technological advances. The impact of these developments on our understanding of the function of the MHC in man and its possible relationship to disease are discussed.