Variations in inflammatory genes are associated with periodontitis

Polymorphism of salivary proteins and risk of periodontal diseases: A systematic review and meta-analysis of clinical studies

OBJECTIVES

The present systematic review and meta-analysis aimed to assess the association between salivary protein polymorphisms and the risk of periodontal diseases (PD).

DATA

The review incorporated cross-sectional, case-control, retrospective/prospective cohort, and randomized controlled trials assessing the influence of salivary protein polymorphisms on the risk of PD development were included in this review.

SOURCES

A thorough literature search was conducted across electronic databases, namely PubMed, Scopus, Embase, and Web of Science, without any restrictions on publication language and year.

STUDY SELECTION

A total of 168 studies were identified, of which 19 were eligible for inclusion. The risk of bias (RoB) assessment of the included studies was conducted at the methodological level.

RESULTS

A total of 16 studies were included. Polymorphism in the gene encoding TNF-α was found to be protective against gingivitis, while those encoding IL-1α and IL-1β were associated with developing gingivitis. Of the 42 proteins investigated, various gene polymorphisms were identified as protective or risk factors for periodontitis. Protective genes include CFH, DNMT1, OPRM1, and TLR9. Conversely, certain salivary protein genes (e.g., CRP, ERN1, FAM5C, IDH2, LTA, TET2, MPA, NLRP3, TLR4) were associated with periodontitis risk. Notably, IL6, MMP9, and MUC7 genes showed no association with PD, while MMP13 was linked to early implant loss. Overall, the meta-analysis found a statistically significant association between salivary proteins' polymorphisms and risk of PD.

CONCLUSIONS

Salivary protein polymorphisms significantly influence PD, revealing protective and risk-associated genotypes. Despite limitations, findings suggest therapeutic targets, emphasizing the complex genetics-periodontal health interplay.

CLINICAL SIGNIFICANCE

This study unveils salivary protein polymorphisms as pivotal factors in PD. Protective genes including CFH and TLR9, and risk-associated genes including CRP and TLR4, indicate a genetic basis for PD susceptibility.

A Systematic Review and Meta-Analysis on Multiple Cytokine Gene Polymorphisms in the Pathogenesis of Periodontitis

Aim

Periodontitis is an inflammatory disease that destroys both soft and hard periodontal tissues. However, a complex periodontal cytokine network remains unclear. This systematic review explored multiple cytokine gene polymorphisms in the pathogenesis of periodontitis.

Material and Methods

A systematic search was performed using the databases from previous publications, which indicated the association between cytokine polymorphisms and periodontitis pathogenesis. Meta-analysis was conducted using fixed or randomized models to calculate the significance of multiple cytokine polymorphisms. A total of 147 articles were analyzed with polymorphisms in 12 interleukins [Th1 (IL-2, IFN-γ, and TNF-α), Th2 (IL-4 and IL-13), Th17 (IL-1α, IL-1β, IL-6, and IL-17), and Treg cytokines (IL-10 and TGF-β)]. Doi plot was used to probe the occurrence of publication bias.

Results

The polymorphisms of IL-2 and TNF-α of Th1 cytokine family may be associated with the pathogenesis or the prevention of periodontitis risk, while the polymorphism of IFN-γ is not related to periodontitis risk. The polymorphisms for IL-4 and IL-13 of Th2 cytokine family are not found to be associated with the pathogenesis of periodontitis. For the polymorphisms of the members of Th17 cytokine family, different IL-1α polymorphisms may have inverse actions in the pathogenesis of periodontitis. IL-1β is a noteworthy cytokine biomarker in periodontitis development and progression. IL-6 may have a protective function in the inflammatory responses of periodontitis, and IL-17 has a weak relationship the inflammatory responses. The polymorphisms for the members of Treg cell cytokines may have a protective function against periodontitis risk. LFK indexes show the major asymmetry due to publication bias.

Conclusion

IL-1β is a notable cytokine biomarker in periodontitis risk. Treg cytokines favor an anti-inflammatory and protective environment. Further data are needed to confirm the present conclusion due to publication bias.

Interferon-Gamma (IFNg) +874A/T Polymorphism Does Not Significantly Affect the Severity of Periodontitis

OBJECTIVES

Interferon-gamma (IFNg) is an immune-regulatory cytokine with a role in host responses to periodontitis. Genetic factors have been reported to modify the corresponding protein expression. The objective of this study was to evaluate the association and role of IFNg polymorphisms, such as IFNg +874 A/T, and the susceptibility to periodontitis.

MATERIALS AND METHODS

A total of 100 unrelated subjects were included in the present study. Genomic deoxyribonucleic acid (DNA) was obtained from peripheral blood of 43 patients with mild periodontitis and 57 patients with severe periodontitis. The determined clinical parameters of periodontitis included probing depth, clinical attachment loss, and papilla bleeding index. The oral hygiene indicators were also assessed. The level of IFNg was determined from the gingival crevicular fluid by enzyme-linked immunosorbent assay technique. The IFNg +874 A/T polymorphisms were analyzed from peripheral blood by the method of restriction fragment length polymorphism-polymerase chain reaction.

STATISTICAL ANALYSIS

Statistical analysis of the results was conducted using chi-squared testing for categorical data. Independent t-tests and Mann-Whitney U tests were used for numeric data. Kruskal-Wallis testing was used to compare genotypes concerning for IFNg +874 A/T polymorphism. A p-value < 0.05 was assumed for statistical significance.

RESULTS

Analysis of the IFNg +874 A/T polymorphism showed no significant differences with the level of IFNg. No significant differences were observed either in IFNg +874 A/T polymorphism between the subjects with mild periodontitis and those with severe periodontitis (p > 0.05). The subjects with severe periodontitis showed marginally but not significantly higher levels of IFNg compared with subjects with mild periodontitis (p > 0.05).

CONCLUSION

The polymorphism of IFNg +874 A/T was not associated with the level of IFNg nor with the risk of periodontitis in this study.

Interleukin-6 gene -174G>C promoter polymorphism reduces the risk of periodontitis in Brazilian populations: A meta-analysis

INTRODUCTION

Periodontitis is a multifactorial host-mediated oral disease caused by microbes. Previous studies suggested that interleukin-6 (IL-6) gene promoter polymorphism (-174G > C) are associated with the risk of periodontitis, although the results were inconclusive. This study investigated the association between IL-6 -174G > C polymorphism and susceptibility to periodontitis.

METHOD

A comprehensive search was conducted in PubMed, EMBASE, Web of Science, and Google Scholar databases to retrieve relevant studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of the association between 174G > C polymorphism and the risk of periodontitis. Cochrane Q and I² statistics were used to measure heterogeneity between studies. Publication bias was estimated using Begg's funnel plots and Egger's test.

RESULTS

Our results showed significant differences in the allelic (C vs. G: OR = 0.82, CI = 0.65-1.03), recessive (CC vs. GC + GG: OR = 0.69, CI = 0.42-1.13), and dominant (GC + CC vs. GG: OR = 0.85, CI = 0.63-1.13) genetic models of the IL6 -174G > C polymorphism and risk of periodontitis. Further, subgroup analysis showed decreased susceptibility to periodontitis associated with IL6 -174 G > C in a Brazilian population (C vs. G: OR = 0.60, CI = 0.41-0.88; GC + CC vs. GG: OR = 0.57, CI = 0.42-0.78) but not in Asian or Caucasian populations.

CONCLUSION

The findings of this study revealed that the IL6 -174 "C" allele is protective against periodontitis in the Brazilian population.

Association of IL-10 -1082A>G, -819C>T, and -592C>A polymorphisms with susceptibility to chronic and aggressive periodontitis: a systematic review and meta-analysis

OBJECTIVES

Several epidemiological studies have evaluated association of interleukin 10 (IL-10) polymorphisms with risk of periodontitis. However, the results remain conflicting and inconclusive. Here, we carried out a comprehensive systematic review and meta-analysis to evaluate the association of IL-10 -1082A>G, -819C>T, and -592C>A polymorphisms with risk of chronic (CP) and aggressive (CP) periodontitis.

METHODS

Electronic databases including PubMed, Science Direct, SciELO, and CNKI were systematically searched to identify all relevant studies published up to 01 June 2020.

RESULTS

A total of 60 case-control studies with 5313 cases and 6528 controls met our inclusion criteria. Overall, the pooled data showed that the IL-10 -592C>A polymorphism was statistically associated with increased risk of periodontitis in the overall population, while no significant association was identified for IL-10 -1082A>G and IL-10 -819C>T polymorphisms. The subgroup analysis by ethnicity revealed that the IL-10 -1082A>G polymorphism was significantly associated with periodontitis risk in Caucasians, IL-10 -819C>T polymorphism in mixed population, and IL-10 -592C>A polymorphism in both Asians and mixed populations. When further analyzed by periodontitis type, only the IL-10 -592C>A polymorphism was associated with CP risk, but not AgP; and the IL-10 -1082A>G and -819C>T polymorphisms have not positive association neither in the CP and AgP.

CONCLUSIONS

The current meta-analysis showed that the IL-10 -592C>A polymorphism was statistically associated with periodontitis risk in the overall population. Moreover, the IL-10 -1082A>G, IL-10 -819C>T, and IL-10 -592C>A polymorphisms were associated with periodontitis risk by ethnicity. Therefore, the IL-10 polymorphisms are of high clinical relevance by ethnicity and would be a useful marker to identify patients who are at higher risk for periodontitis.

Vascular Endothelial Growth Factor: A Translational View in Oral Non-Communicable Diseases

Vascular endothelial growth factors (VEGFs) are vital regulators of angiogenesis that are expressed in response to soluble mediators, such as cytokines and growth factors. Their physiologic functions include blood vessel formation, regulation of vascular permeability, stem cell and monocyte/macrophage recruitment and maintenance of bone homeostasis and repair. In addition, angiogenesis plays a pivotal role in chronic pathologic conditions, such as tumorigenesis, inflammatory immune diseases and bone loss. According to their prevalence, morbidity and mortality, inflammatory diseases affecting periodontal tissues and oral cancer are relevant non-communicable diseases. Whereas oral squamous cell carcinoma (OSCC) is considered one of the most common cancers worldwide, destructive inflammatory periodontal diseases, on the other hand, are amongst the most prevalent chronic inflammatory conditions affecting humans and also represent the main cause of tooth loss in adults. In the recent years, while knowledge regarding the role of VEGF signaling in common oral diseases is expanding, new potential translational applications emerge. In the present narrative review we aim to explore the role of VEGF signaling in oral cancer and destructive periodontal inflammatory diseases, with emphasis in its translational applications as potential biomarkers and therapeutic targets.

Association between TNF-α G-308A (rs1800629) polymorphism and susceptibility to chronic periodontitis and type 2 diabetes mellitus: A meta-analysis

BACKGROUND AND OBJECTIVE

Although the association between tumor necrosis factor-α (TNF-α) G-308A (rs1800629) polymorphism and chronic periodontitis (CP), chronic periodontitis with type 2 diabetes mellitus (DP) is assumed, results of this association have been contradictory. The aim of this study was to assess the relationship between rs1800629 polymorphism and CP/DP susceptibility.

METHODS

We searched for studies on PubMed, Web of Science, MEDLINE, Chinese National Infrastructure, and WanFang databases. Study selection was performed using specific inclusion and exclusion criteria and fulfilled the PECO (participant, exposure, comparison, and outcome) format. The relationship between rs1800629 polymorphism and CP/DP susceptibility was evaluated by the effect summary odds ratio (OR) and 95% confidence intervals (CIs). Allele, dominant, and recessive genetic models were computed to assess the strength of the association.

RESULTS

A total of 25 case-control studies were included in the analysis. In the Asian population, TNF-α rs1800629 polymorphism was found to be significantly associated with CP in the overall analyses and for all genetic contrasts, while no significant risks were found among Caucasian populations for all genetic contrasts. The TNF-α rs1800629 polymorphism was also associated with increased DP risk in Asians under the fixed-effects model, but not in the recessive comparison.

CONCLUSION

The meta-analysis suggested that TNF-α rs1800629 polymorphism might affect the risk of CP and DP, particularly in individuals of Asian descent.

Cytokines and Their Genetic Polymorphisms Related to Periodontal Disease

Periodontal disease (PD) is a chronic inflammatory disease caused by the accumulation of bacterial plaque biofilm on the teeth and the host immune responses. PD pathogenesis is complex and includes genetic, environmental, and autoimmune factors. Numerous studies have suggested that the connection of genetic and environmental factors induces the disease process leading to a response by both T cells and B cells and the increased synthesis of pro-inflammatory mediators such as cytokines. Many studies have shown that pro-inflammatory cytokines play a significant role in the pathogenesis of PD. The studies have also indicated that single nucleotide polymorphisms (SNPs) in cytokine genes may be associated with risk and severity of PD. In this narrative review, we discuss the role of selected cytokines and their gene polymorphisms in the pathogenesis of periodontal disease.

Sex Hormones and Inflammation Role in Oral Cancer Progression: A Molecular and Biological Point of View

Oral cancers have been proven to arise from precursors lesions and to be related to risk behaviour such as alcohol consumption and smoke. However, the present paper focuses on the role of chronic inflammation, related to chronical oral infections and/or altered immune responses occurring during dysimmune and autoimmune diseases, in the oral cancerogenesis. Particularly, oral candidiasis and periodontal diseases introduce a vicious circle of nonhealing and perpetuation of the inflammatory processes, thus leading toward cancer occurrence via local and systemic inflammatory modulators and via genetic and epigenetic factors.

Association of interleukin-10-1082 (-1087) A > G polymorphisms and periodontitis risk: An updated meta-analysis based on 26 case-control studies

BACKGROUND

The association between interleukin-10 (IL-10)-1082 (-1087) A > G polymorphism and either chronic (CP) or aggressive periodontitis (AgP) susceptibility was conflicting. This meta-analysis aimed to quantitatively estimate the association.

METHODS

Pubmed, Embase, Web of Science, and WANFAN databases were searched for relevant studies that were submitted prior to January 31, 2018, and meta-analyses were performed using STATA 14.0.

RESULTS

Database mining yielded 26 studies of interest. For the IL-10-1082 (-1087) A > G (rs1800896) polymorphism and its relation to CP susceptibility, the overall analysis showed no significant estimates, but subgroup analysis revealed significant associations in the AA versus GG + GA model in the Caucasian population (odds ratio [OR] = 1.274, 95% confidence interval [CI] = 1.069-1.518, P = 0.007; I²  = 0.0%, P = 0.483) and in the GG versus AA + AG model in the Han population (OR = 6.66, 95% CI = 7.72-9.41, P = 0.000; I²  = 0.0%, P = 0.82), which all showed no obvious publication bias by Egger's linear regression test. For the association between an IL-10-1082 (-1087) A > G polymorphism and AgP susceptibility, the overall analysis and Caucasian subgroup analysis yielded nonsignificant estimates.

CONCLUSIONS

Our meta-analysis indicated that the IL-10-1082 (-1087) AA genotype in the Caucasian population, and the GG genotype in the Han population might be putative risk factors for CP.

PRACTICAL IMPLICATIONS

The IL-10-1082 (-1087) AA genotype and the GG genotype might be potential biomarkers for Caucasian CP and for Han CP, respectively. However, additional research will be required to validate the findings of this meta-analysis.

Are There Any Common Genetic Risk Markers for Rheumatoid Arthritis and Periodontal Diseases? A Case-Control Study

Background

Several studies suggest that there is a biologically plausible connection between rheumatoid arthritis (RA) and periodontal diseases (PD). Both disorders are characterized as multifactorial diseases potentially sharing common risk factors. Based on the inflammatory nature of RA and PD, the impact of genetic variations of genes of the immune system on both diseases was studied in this study.

Materials and Methods

We conducted a case-control study (n = 201) comparing 101 RA patients suffering from periodontal disease of different severities (no/mild PD vs. severe PD) with 100 systemically healthy controls without RA and severe PD. The genotype, allele, and haplotype distributions of 22 SNPs of 13 pro- and anti-inflammatory cytokines were assessed applying sequence-specific PCR.

Results

Evaluating the impact of cytokine SNPs in RA, we identified the G allele of rs1801275 in IL4Rα (p = 0.043) and the G allele of rs361525 in TNFα (p = 0.005) as disease-associated risk factors in bivariate analyses. In multivariate analyses, these significant associations could not be proven. The A allele of rs2430561 in IFNγ was indicative for severe periodontitis among the patients with rheumatoid arthritis (p = 0.039). Investigating the impact of rs2430561 in IFNγ on comorbidity using binary logistic regression analyses, the A allele was confirmed as an independent risk factor for severe periodontal disease and RA (p = 0.024).

Conclusions

These results emphasize the association of genetic variations in proinflammatory cytokines (TNFα and IFNγ) and cytokine receptor (IL4Rα) and RA and periodontal diseases. In multivariate analyses, the A allele of IFNγ was proven to be a significant marker of RA and PD comorbidities. The study broadens the knowledge about disease-specific differences in genetic composition and provides an improved understanding of a possible association of both diseases.

Environmental lead effects on gene expression in oral epithelial cells

BACKGROUND AND OBJECTIVE

Host responses in periodontitis span a range of local and emigrating cell types and biomolecules. Accumulating evidence regarding the expression of this disease across the population suggests some component of genetic variation that controls onset and severity of disease, in concert with the qualitative and quantitative parameters of the oral microbiome at sites of disease. However, there remains little information regarding the capacity of accruing environmental stressors or modifiers over a lifespan at both the host genetic and microbial ecology levels to understand fully the population variation in disease. This study evaluated the impact of environmental lead exposure on the responses of oral epithelial cells to challenge with a model pathogenic oral biofilm.

METHODS AND RESULTS

Using NanoString technology to quantify gene expression profiles of an array of 511 host response-associated genes in the epithelial cells, we identified an interesting primary panel of basal responses of the cells with numerous genes not previously considered as major response markers for epithelial cells, eg, interleukin (IL)-32, CTNNB1, CD59, MIF, CD44 and CD99. Even high levels of environment lead had little effect on these constitutive responses. Challenge of the cells with the biofilms (Streptococcus gordonii/Fusobacterium nucleatum/Porphyromonas gingivalis) resulted in significant increases in an array of host immune-related genes (134 of 511). The greatest magnitude in differential expression was observed with many genes not previously described as major response genes in epithelial cells, including IL-32, CD44, NFKBIA, CTSC, TNFAIP3, IL-1A, IL-1B, IL-8 and CCL20. The effects of environmental lead on responses to the biofilms were mixed, although levels of IL-8, CCL20 and CD70 were significantly decreased at lead concentrations of 1 and/or 5 μmol/L.

CONCLUSION

The results provided new information on a portfolio of genes expressed by oral epithelial cells, targeted substantial increases in an array of immune-related genes post-biofilm challenge, and a focused impact of environmental lead on these induced responses.

The effects of IL-10 gene polymorphism on serum, and gingival crevicular fluid levels of IL-6 and IL-10 in chronic periodontitis

OBJECTIVE

Anti-inflammatory cytokines play a crucial role in periodontitis by inhibiting synthesis of pro-inflammatory cytokines. The purpose of this study was to evaluate the effect of interleukin-10 (-597) gene polymorphism and genotype distributions on chronic periodontitis (CP) development and IL-6 and IL-10 levels in gingival crevicular fluid (GCF) and serum before and after non-surgical periodontal treatment.

MATERIAL AND METHODS

The study population consisted of 55 severe generalized CP patients as CP group and 50 healthy individuals as control group. Plaque index, gingival index, probing depth and clinical attachment level were recorded and GCF and blood samples were taken at both the baseline and the sixth week after non-surgical periodontal treatment. PCR-RFLP procedure was used for gene analyses and cytokine levels were measured via ELISA.

RESULTS

IL-10 genotype distribution was significantly different between CP and control groups (p=0.000, OR:7, 95%CI, 2.83-60.25). Clinical measurements significantly improved in the CP group after periodontal treatment (p<0.05). Periodontal treatment significantly decreased GCF IL-6 and IL-10 levels. No significant difference was found in clinical parameters between IL-10 AA and AC+CC genotypes at both the baseline and the sixth week (p>0.05). Sixth week GCF IL-10 levels were significantly lower in patients carrying IL-10 AC+CC genotype compared to the patients carrying IL-10 AA genotype (p<0.05). Serum IL-6 and IL-10 levels were lower in patients carrying the IL-10 AA genotype compared to patients with IL-10 AC+CC genotype, but the difference was not significant (p>0.05).

CONCLUSION

IL-10 AA genotype carriers had lower IL-6 and IL-6/10 levels in serum; however, GCF IL-6/10 levels were similar in both genotypes. Within the limitations of our study, a possible association between IL-10(-597) gene polymorphism and CP might be considered.

Is there an association between IFN-γ +874A/T polymorphism and periodontitis susceptibility?: A meta-analysis

BACKGROUND

Interferon-γ (IFN-γ) is a key proinflammatory cytokine which plays a critical role in the pathogenesis and progression of periodontitis. The single nucleotide polymorphism of +874A/T in human IFN-γ gene can influence the secretion of IFN-γ and affect periodontitis susceptibility. However, the findings of published studies are inconsistent. Therefore, the goal of this meta-analysis is to investigate whether there is an association between IFN-γ +874A/T polymorphism and periodontitis susceptibility.

METHODS

PubMed and the Cochrane Library were searched for eligible clinical studies. The odds ratio (OR) and 95% confidence interval (CI) of each study were pooled to estimate the strength of association between +874A/T and periodontitis. Subgroup analyses were performed to explore whether particular characteristics of studies were related to the overall results.

RESULTS

Seven studies and a total of 1252 periodontitis patients and 1622 periodontitis-free control subjects were included. No difference was observed in genotype distribution and allele frequency between periodontitis patients and control (T vs A: OR  =  1.01, 95% CI: 0.90-1.13, P  =  .878; TT vs AA: OR  =  1.07, 95% CI: 0.87-1.32, P  =  .537; AT vs AA: OR  =  1.00, 95% CI: 0.81-1.23, P  =  .996; TT+AT vs AA: OR  =  1.00, 95% CI: 0.84-1.19, P  =  .990; TT vs AA+AT: OR  =  1.03, 95% CI: 0.86-1.23, P  =  .733). Besides, the subgroup analysis based on ethnicity, type of periodontitis, and smoking status failed to identify significant differences in each model, either.

CONCLUSIONS

The results of this meta-analysis suggest that IFN-γ +874 A/T polymorphism may not contribute to periodontitis susceptibility. High quality and well-designed studies which combine genetic and other environmental risk factors are needed to validate this conclusion in the future.

Association Study of Vitamin D Receptor (VDR) - Related Genetic Polymorphisms and their Haplotypes with Chronic Periodontitis in Colombian Population

INTRODUCTION

There is strong evidence that both genetic and environmental factors may affect the periodontal clinical status. However, epidemiological evidence on the association between Vitamin D Receptor (VDR) polymorphisms and Chronic Periodontitis (CP) has been inconsistent.

AIM

The focus of this study was to identify if a possible association between VDR Single-Nucleotide Polymorphisms (SNPs) may be implicated in the aetiopathogenesis of CP in Colombian population.

MATERIALS AND METHODS

One hundred and ten CP patients and 50 Healthy Controls (HC) were recruited. Periodontal status was assessed based on probing depth, clinical attachment level, extent, and severity of periodontal breakdown. The polymerase chain reaction-restriction fragment length polymorphism method was used to identify the VDR rs7975232, rs1544410, rs2228570, and rs731236 SNPs from saliva samples. Odds Ratios (ORs) along with their 95% Confidence Intervals (CIs) were computed to compare the distribution of genotypes/alleles between HC and CP patients, alongside with analysis of Linkage Disequilibrium (LD) and haplotype associations between SNPs. Also, an analysis of the interaction between genetic findings and those significant demographic factors was performed for all SNPs.

RESULTS

There was no association neither between the different genotypes/allele frequencies nor haplotypes and CP. Similarly, no significant differences in extent or severity amongst genotype/allele groups were observed. Even so, interaction analysis revealed significant synergistic interactions between each SNP and age associated with the disease status.

CONCLUSION

Although these results do not support that VDR SNPs could be identified as independent risk predictor variables for CP in the Colombian population, synergistic biological interactive effects of all these SNPs related to age might play a significant role in the pathogenic pathways of CP.

Interleukin-6-174G/C Polymorphism Contributes to Periodontitis Susceptibility: An Updated Meta-Analysis of 21 Case-Control Studies

Introduction. Chronic Periodontitis (CP) is suggested to be related to gene variations. Present study aims to quantitatively estimate the association between interleukin-6- (IL-6-) 174G/C polymorphism and CP susceptibility. Materials and Methods. Pubmed, Embase, and Web of Science were searched up to May 2016. The meta-analyses were performed using STATA 12.0. Results. 21 studies were yielded. Significant associations were found under heterozygote comparison and dominant model in studies fulfilling HWE (GC versus GG: OR = 0.690, 95% CI = 0.560–0.849, P = 0.000; CC + GC versus GG: OR = 0.690, 95% CI = 0.568–0.838, P < 0.001); significant associations were found under heterozygote comparison and dominant model in Caucasian studies fulfilling HWE (GC versus GG: OR = 0.752, 95% CI = 0.577–0.980, P = 0.035; CC + GC versus GG: OR = 0.737, 95% CI = 0.576–0.944, P = 0.016); significant associations were found under allele comparison, heterozygote comparison, and dominant model in Brazilian population (C versus G: OR = 0.648, 95% CI = 0.497–0.845, P = 0.001; GC versus GG: OR = 0.621, 95% CI = 0.441–0.876, P = 0.007; CC + GC versus GG: OR = 0.649, 95% CI = 0.470–0.896, P = 0.009). Conclusion. IL-6 174 polymorphism is associated with CP susceptibility. In Brazilian and Caucasian population, IL-6 174 GG genotype plays as a risk factor to CP.

Fine-tuning of Th17 Cytokines in Periodontal Disease by IL-10

Periodontitis (PD) is a chronic disease caused by the host inflammatory response to bacteria colonizing the oral cavity. In addition to tolerance to oral microbiome, a fine-tuned balance of IL-10 levels is critical to efficiently mount antimicrobial resistance without causing immunopathology. Clinical and animal studies support that adaptive T-helper (Th) cytokines are involved in the pathogenesis of alveolar bone destruction in PD. However, it remains unclear what type of Th response is related to human PD progression and what role IL-10 has on this process. We addressed the contribution of IL-10 in limiting Th1 and Th17 inflammatory response in murine and human PD. Through a combination of basic and translational approaches involving selected cytokine-deficient mice as well as human genetic epidemiology, our results demonstrate the requirement for IL-10 in fine-tuning the levels of Th17 (IL-17A and IL-17F) cytokines in experimental and human PD. Of novelty, we found that IL-17F correlated with protection in murine and human PD and was positively regulated by IL-10. To our knowledge, this is the first demonstration of the protective role for IL-17F in PD, its positive regulation by IL-10, and the potential differential role for IL-17A and IL-17F in periodontal disease.

Polymorphisms in the interleukin-10 gene and chronic periodontitis in patients with atherosclerotic and aortic aneurysmal vascular diseases

Background

Chronic periodontitis (CP), atherosclerotic and aortic aneurysmal vascular diseases (VD) are chronic inflammatory conditions with multifactorial etiologies, including involvement of predisposing genetic factors. In a previous study, polymorphisms in the gene for the anti-inflammatory interleukin-1 receptor antagonist were associated with CP in patients with VD.

Objective

This study investigates whether polymorphisms in the gene for the anti-inflammatory interleukin-10 (IL10) could be related to CP in the same manner.

Methods

Seventy-two patients with VD of whom 35 had CP were genotyped for single nucleotide polymorphisms (SNPs) in the IL10 −592 (rs1800872), −819 (rs1800871), and −1,082 (rs1800896) gene by Taqman rtPCR method and by DNA sequencing.

Results

The C alleles and C/C genotypes of IL10 −592 and IL10 −819 frequencies were significantly higher, while the frequencies of the IL10 −592 (C/A) and IL10 −819 (C/T) heterozygote genotypes were significantly lower in the VD group with CP compared to those without CP. The IL10 haplotype ATA frequency (−1,082, −819, −592) showed a trend to a significant difference between the two groups indicating protection against CP.

Conclusions

Taken together, our findings suggest an independent association of genetic polymorphisms in the IL-10 gene locus with CP in patients with VD. Development of CP and the implications on vascular disease emphasize the importance of early detection and adequate treatment of periodontitis among these patients.

Primary failure rate for 1680 extra-alveolar mandibular buccal shelf mini-screws placed in movable mucosa or attached gingiva

OBJECTIVE

To compare the initial failure rate (≤4 months) for extra-alveolar mandibular buccal shelf (MBS) miniscrews placed in movable mucosa (MM) or attached gingiva (AG).

MATERIALS AND METHODS

A total of 1680 consecutive stainless steel (SS) 2 × 12-mm MBS miniscrews were placed in 840 patients (405 males and 435 females; mean age, 16 ± 5 years). All screws were placed lateral to the alveolar process and buccal to the lower first and second molar roots. The screw heads were at least 5 mm superior to the soft tissue. Loads from 8 oz-14 oz (227 g-397 g, 231-405 cN) were used to retract the mandibular buccal segments for at least 4 months.

RESULTS

Overall, 121 miniscrews out of 1680 (7.2%) failed: 7.31% were in MM and 6.85% were in AG (statistically insignificant difference). Failures were unilateral in 89 patients and bilateral in 16. Left side (9.29%) failures was significantly greater (P < .001) compared with those on the right (5.12%). Average age for failure patients was 14 ± 3 years.

CONCLUSION

MBS miniscrews were highly successful (approximately 93%), but there was no significant difference between placement in MM or AG. Failures were more common on the patient's left side and in younger adolescent patients. Having 16 patients with bilateral failures suggests that a small fraction of patients (1.9%) are predisposed to failure with this method.

Correlation of Toll-like receptor 4, interleukin-18, transaminases, and uric acid in patients with chronic periodontitis and healthy adults

BACKGROUND

Because of the potential association between periodontal disease and inflammation, the purpose of the present study is to examine the level of Toll-like receptor 4 (TLR-4), interleukin-18 (IL-18), and uric acid as markers of the inflammatory host response in the plasma and saliva of healthy individuals and patients with periodontitis. In addition, routine biochemical parameters such as fasting glucose, insulin, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, alanine transaminase (ALT), and aspartate transaminase (AST) were measured. The authors also wanted to check whether patients with chronic periodontitis (CP) exhibit different modulations in salivary and/or plasma concentrations of these parameters compared with clinically healthy individuals.

METHODS

Saliva and plasma samples were collected from 40 patients with CP and 20 healthy individuals. TLR-4 and IL-18 measurements were done using commercially available enzyme-linked immunosorbent assay kits. Total, HDL, and LDL cholesterol; triglycerides; fasting glucose; AST; and ALT levels were analyzed on a biochemistry analysis system using specific kits. Non-parametric tests were used for certain parameters in the statistical analyses because the data did not follow Gaussian distribution.

RESULTS

Significant differences were observed in plasma and salivary TLR-4 and IL-18 levels, along with clinical measurements such as plaque index and probing depth, in patients with CP (P < 0.001). The plasma level of TLR-4 was found to be increased from 0.99 to 3.28 ng/mL in patients with CP. Salivary TLR-4 levels also showed a slightly higher increase in the diseased state (12.44 to 29.97 ng/mL). A significant increase of ≈ 46% was recorded in the plasma IL-18 level. However, salivary IL-18 levels rose up to > 5-fold in the patients with CP compared with healthy individuals. The level of plasma uric acid was found to be highly significantly increased compared with control individuals. HDL cholesterol and triglyceride also showed significant differences (P < 0.02 and P < 0.03, respectively). Plasma glucose, total cholesterol, LDL cholesterol, and insulin levels did not show any significant difference. There was only a slight increase in plasma AST and ALT levels between diseased and healthy states (22.55 versus 25.50 IU/L and 12.35 versus 15.95 IU/L, respectively). However, salivary AST and ALT levels showed a ≈ 6-fold rise in the patients with CP compared with the healthy individuals. Cross-correlation analysis in the periodontitis disease group showed a significant association of plasma AST, salivary AST, and salivary ALT with uric acid level.

CONCLUSIONS

Based on this study, the authors believe that TLR-4, IL-18, and uric acid could have a role in the inflammatory pathology of periodontitis. These parameters are suggested to be useful in the prognosis and diagnosis of CP. However, the mechanistic association of these parameters with inflammatory pathology of patients with periodontitis needs to be further elucidated in a higher number of samples.