Association between the IL-10 rs1800872 polymorphisms and periodontitis susceptibility: A meta-analysis.

BACKGROUND: Periodontitis is a common disease with an unclear pathological mechanism. No precise consensus has been reached to evaluate the association between the IL-10 rs1800872 (- 592, -590, -597 C>A) polymorphism and periodontal disease. Thus, we performed this meta-analysis to collect more evidence-based information. METHODS: Four online databases, PubMed, Embase, Web of Science, and China Biology Medicine disc (CBM), were searched in August 2018. An odds ratio (OR) with a 95% confidence interval (CI) was applied to evaluate the association of the rs1800872 with periodontitis susceptibility. RESULTS: Twenty three case-control studies with 2714 patients and 2373 healthy controls were evaluated. The overall analyses verified that the IL-10 rs1800872 polymorphism was significantly associated with an increased risk of periodontitis in the allelic model, homozygote model, dominant model, and recessive model (A vs C: OR = 1.28, 95%CI = 1.11-1.49, P = .00, I = 56.87%; AA vs CC: OR = 2.06, 95%CI = 1.32-3.23, P = .00, I = 73.3%; AA + AC vs CC: OR = 1.42, 95%CI = 1.03-1.96, P = .03, I = 76.2%; AA vs AC + CC: OR = 1.78, 95%CI = 1.26-2.56, P = .00, I = 76.7%). Moreover, the subgroup analysis based on ethnicity, periodontitis type, and smoking status showed significant differences. CONCLUSIONS: The results of our meta-analysis demonstrate that rs1800872 is associated with periodontitis susceptibility in Caucasians and Asians. Moreover, A allele, AA genotype, CC genotype may be closely associated with chronic periodontitis (CP), while A allele, AA genotype may be closely associated with aggressive periodontitis (AgP).

Association between interleukin-10 gene polymorphisms and severe chronic periodontitis.

OBJECTIVE: Periodontitis is an inflammatory disease that is a result of the interaction between pathogenic bacteria and host immune response. Genetic alterations in interleukin-10 (IL-10) gene may be associated with the increased risk of periodontitis. We investigated the association between genotype and haplotype frequencies of IL-10 gene polymorphisms and susceptibility to periodontitis in an Iranian population. METHODS: In this case-control study, a total of 64 patients with periodontitis and 128 healthy subjects were recruited. The PCR-RFLP technique was used to detect IL-10 promoter genotypes at the positions of -1082 (G/A), -819 (C/T), and -592 (C/A) in association with the susceptibility to severe chronic periodontitis. RESULTS: Regarding IL-10 -592 (C/A) and IL-10 -819 (C/T) alleles and genotypes, no significant association was observed between the risk of periodontitis and genotype frequencies. However, the frequency of GG genotype in IL-10 -1082 (G/A) polymorphic region was higher in normal subjects and was associated with the decreased risk of periodontitis under recessive model [OR = 2.89, 95% CI (0.99-8.43), p = 0.039]. Haplotype analysis revealed a significantly higher presence of H7 (AGC; -592/-1082/-819) [OR = 97.74, 95% CI (95.52-99.96), p < 0.0001]. CONCLUSION: IL-10 -1082(G/A) polymorphism and AGC (-592/-1082/-819) haplotype could be associated with the susceptibility to chronic periodontitis.

The role of three interleukin 10 gene polymorphisms (- 1082 A > G, - 819 C > T, - 592 A > C) in the risk of chronic and aggressive periodontitis: a meta-analysis and trial sequential analysis.

BACKGROUND: Periodontitis is a major oral health problem and it is considered as one of the reasons for tooth loss in developing and developed nations. The objective of the current review was to investigate the association between IL10 polymorphisms - 1082 A > G (rs1800896), -819C > T (rs1800871), - 592 A > C (rs1800872) and the risk of either chronic periodontitis or aggressive periodontitis. METHODS: This is a meta- analysis study, following the preferred reporting items for systematic reviews and meta- analyses (PRISMA). Relevant studies were searched in the health related electronic databases. Methodological quality of the included studies were assessed using the Newcastle-Ottawa Scale. For individual studies, odds ratio (OR) and its 95%confidence interval (CI) were calculated to assess the strength of association between IL10 polymorphisms (- 1082 A > G, -819C > T, - 592 A > C) and the risk of periodontitis. For pooling of the estimates across studies included, the summary OR and its 95% CIs were calculated with random-effects model. The pooled estimates were done under four genetic models such as the allelic contrast model, the recessive model, the dominant model and the additive model. Trial sequential analysis (TSA) was done for estimation of the required information size for this meta-analysis study. RESULTS: Sixteen studies were identified for this review. The included studies were assessed to be of moderate to good methodological quality. A significant association between polymorphism of IL10-1082 A > G polymorphism and the risk of chronic periodontitis in the non-Asian populations was observed only in the recessive model (OR,1.42; 95% CI:1.11, 1.8,I2: 43%). The significant associations between - 592 A > C polymorphism and the risk of aggressive periodontitis in the non-Asian populations were observed in particular genetic models such as allele contrast (OR, 4.34; 95%CI:1.87,10.07,I2: 65%) and recessive models (OR, 2.1; 95% CI:1.16, 3.82,I2: 0%). The TSA plot revealed that the required information size for evidence of effect was sufficient to draw a conclusion. CONCLUSIONS: This meta-analysis suggested that the IL10-1082 A > G polymorphism was associated with chronic periodontitis CP risk in non-Asians. Thus, in order to further establish the associations between IL10 (- 819 C > T, - 592 A > C) in Asian populations, future studies should include larger sample sizes with multi-ethnic groups.

Evaluation of Association of Vitamin D Receptor Genetic Polymorphism with Severe Chronic Periodontitis in an Ethnic Tamilian Population.

BACKGROUND: Periodontitis is a multifactorial disease characterized by inflammatory responses to increased levels of subgingival pathogens, resulting in connective tissue destruction and alveolar bone loss. The susceptibility of an individual is determined by the complex interplay of the host, genetic, and environmental factors. Vitamin D, a secosteroid hormone, interacts with its nuclear receptor vitamin D receptor (VDR) to regulate crucial biological processes, such as bone metabolism and immune function modulation. Various studies have been conducted in different populations to analyze the association of VDR gene polymorphisms with chronic periodontitis, as these polymorphisms have been demonstrated to play vital roles in the pathogenesis of other diseases. OBJECTIVE: The aim of the present study was to determine the prevalence and association of the VDR TaqI gene polymorphism with severe chronic periodontitis in an Ethnic Tamilian population. MATERIALS AND METHODS: A total of 140 subjects were recruited for the study, of which 70 were diagnosed with severe chronic periodontitis and 70 had healthy gums. Each subject's medical and dental histories were taken, and periodontal examinations were performed. Genomic DNA was extracted and genotyping of the VDR gene at the TaqI site was carried out using polymerase chain reaction/restriction fragment length polymorphism. The frequencies of genotypes and alleles were analyzed between the study groups. RESULTS: The frequency of homozygous TT genotype was 40%, for both the severe chronic periodontitis and the healthy control groups. The distribution of heterozygous Tt genotype was 42.9% in the severe chronic periodontitis group and 47.1% in the healthy control group. The frequency of homozygous tt genotype was 17.1% in the severe chronic periodontitis group and 12.7% in the healthy control group. Although the prevalence of genotype tt and t allele was slightly increased in severe chronic periodontitis patients compared with healthy controls, the frequency of VDR genotype between the study groups was not statistically significant (p-value = 0.751). CONCLUSION: This present study performed in an Ethnic Tamilian population does not support an association between either of the TaqI alleles within the VDR gene and Severe Chronic Periodontitis.

Interleukin-10 polymorphisms affect the key periodontal pathogens in Chinese periodontitis patients.

Interleukin-10 (IL-10) polymorphisms have been shown to affect IL-10 production. This study investigated the influences of IL-10 polymorphisms on the susceptibility to chronic periodontitis (CP) and aggressive periodontitis (AP), and their possible role in the quantity of subgingival bacteria Aggregatibacter Actinomycetemcomitans and Porphyromonas gingivalis. 92 CP patients, 83 AP patients and 91 periodontal healthy controls were recruited. Serum IL-10 concentration was analyzed by enzyme-linked immunosorbent assay (ELISA). Gene polymorphisms were determined by multiplex SNaPshot technique. Bacteria were quantified by real-time polymerase chain reaction with TaqMan MGB probes. Taking into account age, gender and periodontal status, IL-10-592 AA, -819 TT and ATA/ATA genotype occurred more frequently in patients with CP than in healthy controls. In CP cases, higher quantity of subgingival A. actinomycetemcomitans and lower serum IL-10 levels could be detected in homozygous ATA/ATA carriers. These findings indicate that variants in IL-10 promoter gene were not only associated with predisposition to chronic periodontitis but also affected the subgingival number of A. Actinomycetemcomitans in a Chinese Han population.

Serum vitamin D levels and chronic periodontitis in adult, Caucasian population-a systematic review.

The aim of this systematic review was to explore the relationship between serum vitamin D levels and periodontal disease. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The focused PICO question was: Are serum vitamin D levels (I) associated with gingivitis or periodontitis (C) in healthy humans (P)? PubMed (Medline), Embase, Science Direct, the Cochrane library, and grey literature were searched up to 31 July 2017. Two reviewers independently selected studies and extracted data. Quality, risk of bias, and heterogeneity of the studies were assessed using the Newcastle-Ottawa Scale. In total, 365 studies were identified and 24 were analyzed. Seven studies fulfilled the inclusion criteria. Four case-control studies showed an influence of vitamin D and its metabolites on periodontal health status/disease. One interventional study suggested the proposed anti-inflammatory role of vitamin D. Two cross-sectional studies failed to show a relationship between vitamin D and periodontal condition. The literature on the effect of serum vitamin D levels on periodontal status remains scarce and controversial. Some data, however, support a "perio-protective" role for vitamin D. There is a need for well-designed randomized clinical trials to explore the possible anti-inflammatory effect of vitamin D on periodontal health.

Periodontal surgery improves oral health-related quality of life in chronic periodontitis patients in Asian population.

The effect of periodontal surgery on patients' quality of life was investigated. Sixty patients received regenerative surgery or resective osseous surgery. Oral health-related quality of life and health-related quality of life instruments were used to assess the participants' quality of life before surgery and 4 weeks after surgery. Periodontal surgery can improve patients' quality of life by alleviating the physical pain and psychological discomfort. The scores were lower (more favorable) in the regenerative surgery group, and the functional limitations of the regenerative surgery group improved substantially compared with those of the resective osseous surgery group (P = 0.0421). The patients' oral health-related quality of life scores improved significantly after periodontal surgery. Clinicians can take advantage of the positive functional oral health-related quality of life impacts of regenerative surgery.

[Correlation of matrix metalloproteinase-9 polymorphisms with chronic periodontitis in Uygur adults].

Objective: To investigate the association between matrix metalloproteinase-9 (MMP-9) polymorphisms and chronic periodontitis in Uygur adults. Methods: A total of 196 patients with chronic periodontitis and 97 healthy controls were selected from 2 500 Uygur people. Buccal swab samples were taken, the genomic DNA was extracted and the genotype distribution and allele frequency of MMP-9 were determined by PCR-restriction fragment length polymorphism (PCR-RFLP). The distribution of genotypes, allele frequencies and risk factors were analyzed by chi-square test and multiple logistic regression. Results: Significant difference was found between healthy controls and the mild periodontitis and moderate to severe periodontitis in the MMP-9 1562C/T CC genotype expression (χ(2)=9.901, P=0.002; χ(2)=13.397, P< 0.001), and detectable rate of MMP-9 1562C/T CC genotype in the three groups was 31.3%(30/96), 53.5% (53/99), 27.8%(27/97), respectively. The detectable rate of CT genotype expression in the three groups were 65.6% (63/96), 45.5% (45/99), 69.1% (67/97) respectively and there was significant difference between healthy controls and mild periodontitis and between the mild periodontitis and moderate to severe periodontitis (χ(2)=8.025, P=0.005; χ(2)=11.159, P<0.001). There was also significant difference in allele frequency between healthy controls and mild periodontitis and between mild periodontitis and moderate to severe periodontitis (χ(2)=6.270, P=0.012; χ(2)=8.184, P=0.004). Logistic analysis showed that age under 35 years old was the protective factor of chronic periodontitis (OR=0.061, 95% CI=0.035-0.108, P<0.001) while the male and CT genotype were the risk factors of chronic periodontitis (OR=2.392, 95%CI=1.496-3.819, P<0.001; OR=1.280, 95%CI=0.794-2.067, P=0.031). Conclusions: The susceptibility to chronic periodontitis in Uygur adults in Moyu county of Xinjiang is related to the age and gender and polymorphism of MMP-9. The age over 35 years old, male and CT genotype may be the risk factors of chronic periodontitis in Uygur adults.

Chronic Periodontitis Genome-wide Association Study in the Hispanic Community Health Study / Study of Latinos.

Chronic periodontitis (CP) has a genetic component, particularly its severe forms. Evidence from genome-wide association studies (GWASs) has highlighted several potential novel loci. Here, the authors report the first GWAS of CP among a large community-based sample of Hispanics/Latinos. The authors interrogated a quantitative trait of CP (mean interproximal clinical attachment level determined by full-mouth periodontal examinations) among 10,935 adult participants (mean age: 45 y, range: 18 to 76 y) from the Hispanic Community Health Study / Study of Latinos. Genotyping was done with a custom Illumina Omni2.5M array, and imputation to approximately 20 million single-nucleotide polymorphisms was based on the 1000 Genomes Project phase 1 reference panel. Analyses were based on linear mixed models adjusting for sex, age, study design features, ancestry, and kinship and employed a conventional P < 5 × 10-8 statistical significance threshold. The authors identified a genome-wide significant association signal in the 1q42.2 locus ( TSNAX-DISC1 noncoding RNA, lead single-nucleotide polymorphism: rs149133391, minor allele [C] frequency = 0.01, P = 7.9 × 10-9) and 4 more loci with suggestive evidence of association ( P < 5 × 10-6): 1q22 (rs13373934), 5p15.33 (rs186066047), 6p22.3 (rs10456847), and 11p15.1 (rs75715012). We tested these loci for replication in independent samples of European-American ( n = 4,402) and African-American ( n = 908) participants of the Atherosclerosis Risk in Communities study. There was no replication among the European Americans; however, the TSNAX-DISC1 locus replicated in the African-American sample (rs149133391, minor allele frequency = 0.02, P = 9.1 × 10-3), while the 1q22 locus was directionally concordant and nominally significant (rs13373934, P = 4.0 × 10-2). This discovery GWAS of interproximal clinical attachment level-a measure of lifetime periodontal tissue destruction-was conducted in a large, community-based sample of Hispanic/Latinos. It identified a genome-wide significant locus that was independently replicated in an African-American population. Identifying this genetic marker offers direction for interrogation in subsequent genomic and experimental studies of CP.

Interleukin-8 -251A/T polymorphism and periodontitis susceptibility: a meta-analysis.

The -251A/T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene has been implicated in susceptibility to periodontitis; however, this correlation has not been elucidated. In this meta-analysis, we investigated the association between the IL-8 -251A/T polymorphism and the risk of periodontitis. All eligible case-control studies published until August 2014 were identified and extracted from PubMed, Web of Science, EMBASE, China National Knowledge Internet, and WanFang databases. The strength of this association was accessed by pooled odds ratios (ORs) with 95% confidence intervals (CIs), using either a fixed- or random-effect model. Nine case-control studies, including 1811 cases and 2043 controls, were identified. Overall, no significant associations were found between the IL-8 -251A/T polymorphism and the risk of periodontitis. The results of the analysis of periodontitis subgroup revealed similarities between chronic periodontitis and aggressive periodontitis. An additional analysis based on ethnicity revealed an association between the IL-8 -251A/T polymorphism and periodontitis among Asians (dominant model, OR = 1.784, 95%CI = 1.130-2.817) and a mixed population (AA vs TT, OR = 0.667, 95%CI = 0.471-0.974). The results of this meta-analysis suggest that the IL-8 -251A/T polymorphism may increase the risk of periodontitis in Asian and mixed populations. However, larger and well-designed studies are warranted to validate our findings.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis.

The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.

Complementary clinical effects of red complex bacteria on generalized periodontitis in a caucasian population.

OBJECTIVES: To relate five periodontopathogenic bacteria, including the red complex, to the severity, extent, and inflammation of the periodontal lesion in Caucasian patients with generalized aggressive and chronic periodontitis and to explore whether tobacco use is associated with a specific bacterial profile. MATERIALS AND METHODS: A cross-sectional and analytic study was conducted in patients with aggressive and chronic periodontitis. Data were gathered on socio-demographic and periodontal variables, and RH-PCR was used to determine subgingival bacterial profile. Linear and logistic regression analyses were performed. RESULTS: The study included 60 patients with aggressive and 123 with chronic periodontitis. Total red complex bacteria count was higher in aggressive periodontitis, mainly due to T. denticola (P = 0.015). In both periodontitis types, models showed an association between T. forsythia count and probing depth (B = 0.157, P = 0.030) and between T. denticola count and higher bleeding scores (B = 2.371, P = 0.027). Smoking did not affect the red complex bacteria count in either disease. CONCLUSIONS: The prevalence of red complex bacteria was similar between aggressive and chronic periodontitis, but their count was higher in the former. In both diseases, T. forsythia was associated with greater severity and T. denticola with more severe bleeding. Tobacco smoking was not associated with the presence of red complex bacteria in either disease.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis

Abstract The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.

Occurrence of periodontal pathogens in ethnic groups from a native Brazilian reservation.

OBJECTIVE: The present study was designed to evaluate the occurrence of periodontal pathogens in the subgingival biofilm of 100 native Brazilians living at the Umutina Indian Reservation, Mato Grosso State, Brazil. METHODS: Periodontal clinical examinations were carried out prior to collection of subgingival biofilm, and the presence of 14 periodontal microorganisms was evaluated by polymerase chain reaction (PCR). The prevalence and risk analysis was performed using Cochran and Mantel-Haenszel statistics for dichotomous variables or Pearson's chi-squared test for analysis of proportions when variables had three or more categories. The interrelations between clinical and microbiological parameters were assessed using Fisher's exact test and the Mann-Whitney U test. RESULTS: Individuals with chronic periodontitis were frequently colonized by the association between Porphyromonas gingivalis and Campylobacter rectus, P. gingivalis and Prevotella intermedia, or P. gingivalis and Tannerella forsythia. Patients with chronic periodontitis were also colonized by Porphyromonas gulae and P. intermedia or by the association between P. gulae and T. forsythia. P. gulae was detected only in the subgingival samples from natives on a traditional diet. Gingival bleeding was associated with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, T. forsythia, P. gingivalis, P. gulae, Porphyromonas endodontalis, P. intermedia, and Prevotella nigrescens. Treponema denticola was uncommon. CONCLUSIONS: Peculiar microbiota was demonstrated to be associated with different periodontal disease statuses in native Brazilians, with modest occurrence of certain pathogens, such as T. denticola, and the presence of P. gulae in natives with gingivitis or chronic periodontitis.

Analysis of interleukin-8 gene variants reveals their relative importance as genetic susceptibility factors for chronic periodontitis in the Han population.

Interleukin (IL)-8, an important chemokine that regulates the inflammatory response, plays an important role in periodontitis. Previous studies indicate that certain IL-8 gene polymorphisms are associated with periodontitis susceptibility in some populations. However, the literature is somewhat contradictory, and not all IL-8 polymorphisms have been examined, particularly in Han Chinese individuals. The aim of this study was to investigate the association of every IL-8 SNP with chronic periodontitis in Han Chinese individuals. We analyzed 23 SNPs with minor allele frequency (MAF)≥0.01, which were selected from 219 SNPs in the NCBI dbSNP and preliminary HapMap data analyses from a cohort of 400 cases and 750 controls from genetically independent Han Chinese individuals. Single SNP, haplotype and gender-specific associations were performed. We found that rs4073 and rs2227307 were significantly associated with chronic periodontitis. Further haplotype analysis indicated that a haplotype block (rs4073-rs2227307-rs2227306) that spans the promoter and exon1 of IL-8 was highly associated with chronic periodontitis. Additionally, the ATC haplotype in this block was increased 1.5-fold in these cases. However, when analyzing the samples by gender, no significant gender-specific associations in IL-8 were observed, similar to the results of haplotype association analyses in female and male subgroups. Our results provide further evidence that IL-8 is associated with chronic periodontitis in Han Chinese individuals. Furthermore, our results confirm previous reports suggesting the intriguing possibilities that IL-8 plays a role in the pathogenesis of chronic periodontitis and that this gene may be involved in the etiology of this condition.

Genome wide association scan for chronic periodontitis implicates novel locus.

BACKGROUND: There is evidence for a genetic contribution to chronic periodontitis. In this study, we conducted a genome wide association study among 866 participants of the University of Pittsburgh Dental Registry and DNA Repository, whose periodontal diagnosis ranged from healthy (N = 767) to severe chronic periodontitis (N = 99). METHODS: Genotypingi of over half-million single nucleotide polymorphisms was determined. Analyses were done twice, first in the complete dataset of all ethnicities, and second including only samples defined as self-reported Whites. From the top 100 results, twenty single nucleotide polymorphisms had consistent results in both analyses (borderline p-values ranging from 1E-05 to 1E-6) and were selected to be tested in two independent datasets derived from 1,460 individuals from Porto Alegre, and 359 from Rio de Janeiro, Brazil. Meta-analyses of the Single nucleotide polymorphisms showing a trend for association in the independent dataset were performed. RESULTS: The rs1477403 marker located on 16q22.3 showed suggestive association in the discovery phase and in the Porto Alegre dataset (p = 0.05). The meta-analysis suggested the less common allele decreases the risk of chronic periodontitis. CONCLUSIONS: Our data offer a clear hypothesis to be independently tested regarding the contribution of the 16q22.3 locus to chronic periodontitis.

Higher prevalence of Epstein-Barr virus DNA in deeper periodontal pockets of chronic periodontitis in Japanese patients.

Periodontitis, a complex chronic inflammatory disease caused by subgingival infection, is among the most prevalent microbial diseases in humans. Although traditional microbiological research on periodontitis has focused on putative bacteria such as Porphyromonas gingivalis, the herpes virus is proposed to be involved in the pathogenesis of periodontitis because bacterial etiology alone does not adequately explain various clinical aspects. In this study, we established for the first time, more Epstein-Barr virus (EBV) DNA is found deeper in periodontal pockets of chronic periodontitis in Japanese patients. Subgingival samples were collected from 85 patients with chronic periodontitis having two periodontal sites with probing depths (PD) of ≤ 3 mm (shallow) or ≥ 5 mm (deep) and were subjected to a nested polymerase chain reaction. EBV DNA was more frequently detected in patients with deeper PD sites (66%) than in those with shallow PD sites (48%) or healthy controls (45%). Coexistence of EBV DNA and P. gingivalis was significantly higher in patients with deeper PD sites (40%) than in those with shallow PD sites (14%) or healthy controls (13%). Although no difference in clinical index for periodontitis, the odds ratio of EBV DNA in patients with deeper PD sites was 2.36, which was 2.07-fold higher than that in those with shallow PD sites. Interestingly, the odds of acquiring chronic periodontitis (PD ≥ 5 mm) were higher in the presence of both EBV DNA and P. gingivalis compared with either EBV DNA or P. gingivalis only. In addition, we also observed that EBV-encoded small RNA (EBER) in positive cells of human gingival tissues. These results would suggest that EBV DNA may serve as a pathogenic factor leading to chronic periodontitis among Japanese patients.

Oral microbiome of deep and shallow dental pockets in chronic periodontitis.

We examined the subgingival bacterial biodiversity in untreated chronic periodontitis patients by sequencing 16S rRNA genes. The primary purpose of the study was to compare the oral microbiome in deep (diseased) and shallow (healthy) sites. A secondary purpose was to evaluate the influences of smoking, race and dental caries on this relationship. A total of 88 subjects from two clinics were recruited. Paired subgingival plaque samples were taken from each subject, one from a probing site depth >5 mm (deep site) and the other from a probing site depth ≤3mm (shallow site). A universal primer set was designed to amplify the V4-V6 region for oral microbial 16S rRNA sequences. Differences in genera and species attributable to deep and shallow sites were determined by statistical analysis using a two-part model and false discovery rate. Fifty-one of 170 genera and 200 of 746 species were found significantly different in abundances between shallow and deep sites. Besides previously identified periodontal disease-associated bacterial species, additional species were found markedly changed in diseased sites. Cluster analysis revealed that the microbiome difference between deep and shallow sites was influenced by patient-level effects such as clinic location, race and smoking. The differences between clinic locations may be influenced by racial distribution, in that all of the African Americans subjects were seen at the same clinic. Our results suggested that there were influences from the microbiome for caries and periodontal disease and these influences are independent.

Metabolic syndrome and periodontitis in Gullah African Americans with type 2 diabetes mellitus.

AIM: To assess associations of metabolic syndrome, and its individual components, with extent of severe periodontitis among patients with type 2 diabetes mellitus (T2DM). MATERIALS & METHODS: We performed a secondary data analysis (N = 283) using a cross-sectional study population of Gullah African Americans with T2DM. Extent of severe periodontitis was assessed as total diseased tooth-sites/person [evaluated as separate outcomes: 6+mm clinical attachment level (CAL), 5+mm periodontal probing depth (PPD)] using negative binomial regression techniques. Primary independent variables assessed in separate models included metabolic syndrome (yes/no), each metabolic syndrome component (low HDL, hypertension, high triglycerides, large waist circumference) and glycemic control (poor/good). RESULTS: Multivariable CAL-model results showed a significant association for metabolic syndrome status with extent of severe periodontitis (RR = 2.77, p = 0.03). The separate multivariable CAL-model including each metabolic syndrome component showed marginally increased rates among those with large waist circumference (RR = 2.33, p = 0.09) and those with HbA1c ≥ 7% (RR = 1.73, p = 0.06). Multivariable PPD-models showed marginally increased rates among those with metabolic syndrome (RR = 2.18, p = 0.06). CONCLUSION: Metabolic syndrome is associated with the extent of severe periodontitis in this Gullah population with T2DM.

Association between interleukin-1ß C (3953/4)T polymorphism and chronic periodontitis: evidence from a meta-analysis.

The aim of this study was to perform a meta-analysis to evaluated the association between interleukin-1ß (IL-1ß) C(3953/4)T polymorphism and chronic periodontitis (CP). Systematic searches of electronic databases and hand searching of references were performed, including PubMed, Embase and Web of Science. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated. Publication bias was tested by Begg's funnel plot and Egger's regression test. Sensitivity analysis was conducted by limiting the meta-analysis studies conforming to Hardy-Weinberg equilibrium (HWE) or high quality (score ≥ 7). Data analyses were carried out by Stata 11.0. There were significant associations between IL-1ß C(3953/4)T polymorphism and CP (for T allele vs. C allele: OR = 1.30, 95%CI = 1.05-1.60, p = 0.02; for T/T vs. C/C: OR = 1.66, 95%CI = 1.12-2.45, p = 0.01; for C/T+T/T vs. C/C: OR = 1.28, 95%CI = 0.99-1.65; and for T/T vs. C/T+C/C: OR = 1.62, 95%CI = 1.15-2.29, p = 0.006). When stratified by ethnicity, statistically significantly elevated risk was found for Caucasians, but not for Asians. When stratified by study design, evidences of significant association was observed between IL-1ß C(3953/4)T polymorphism and CP in both population-based studies and hospital-based studies. This meta-analysis indicates that there is strong evidence for association between IL-1ß C(3953/4)T polymorphism and CP.