Herpesviruses in periodontal pocket and gingival tissue specimens

Dental calculus - An emerging bio resource for past SARS CoV2 detection, studying its evolution and relationship with oral microflora

The most grievous threat to human health has been witnessed worldwide with the recent outbreak of Corona virus disease 2019 (COVID-19). There is mounting evidence available regarding theconnect of COVID -19 and oral cavity, particularly periodontal disease. The current review provides an update on the diagnostic potential of dental calculus and how this bio resource may help in providing us huge amount of diagnostic regarding the causative virus. Contemporary standard method of diagnosis via nasopharyngeal swabs (NPS) is tedious, may enhance the risk of aerosol contamination by inducing sneezing and detects the presence of active infection only.However,dental calculus being a mineralized deposit serves as a reservoir for biomoleculesand provides detection of past SARS CoV2 infection. Further, the abundance of information that can be obtained from this remarkable mineralized deposit on teeth regarding the viral genome, its evolution and interactions with the oral microflora shall enhance the understanding of the viral disease process and its connection with the periodontal disease. Additional diagnostic information, which may be obtained from this simple bio reservoir can complement the contemporary diagnostic strategies adopted in the management of COVID-19pandemic and enhance our existing knowledge for developing improvised novel approaches to mitigate the effects of mutated variants of the infectious agent.

Viruses, periodontitis, and comorbidities

Seminal studies published in the 1990s and 2000s explored connections between periodontal diseases and systemic conditions, revealing potential contributions of periodontal diseases in the initiation or worsening of systemic conditions. The resulting field of periodontal medicine led to the publication of studies indicating that periodontal diseases can influence the risk of systemic conditions, including adverse pregnancy outcomes, cardiovascular and respiratory diseases, as well as Alzheimer disease and cancers. In general, these studies hypothesized that the periodontal bacterial insult and/or the associated proinflammatory cascade could contribute to the pathogenesis of these systemic diseases. While investigations of the biological basis of the connections between periodontal diseases and systemic conditions generally emphasized the bacteriome, it is also biologically plausible, under an analogous hypothesis, that other types of organisms may have a similar role. Human viruses would be logical "suspects" in this role, given their ubiquity in the oral cavity, association with periodontal diseases, and ability to elicit strong inflammatory response, compromise immune responses, and synergize with bacteria in favor of a more pathogenic microbial consortium. In this review, the current knowledge of the role of viruses in connecting periodontal diseases and systemic conditions is examined. We will also delve into the mechanistic basis for such connections and highlight the importance of those relationships in the management and treatment of patients.

Epstein-Barr Virus Promotes the Production of Inflammatory Cytokines in Gingival Fibroblasts and RANKL-Induced Osteoclast Differentiation in RAW264.7 Cells

Periodontitis is an inflammatory condition that causes the destruction of the supporting tissues of teeth and is a major public health problem affecting more than half of the adult population worldwide. Recently, members of the herpes virus family, such as the Epstein–Barr virus (EBV), have been suggested to be involved in the etiology of periodontitis because bacterial activity alone does not adequately explain the clinical characteristics of periodontitis. However, the role of EBV in the etiology of periodontitis is unknown. This study aimed to examine the effect of inactivated EBV on the expression of inflammatory cytokines in human gingival fibroblasts (HGFs) and the induction of osteoclast differentiation. We found that extremely high levels of interleukin (IL)-6 and IL-8 were induced by inactivated EBV in a copy-dependent manner in HGFs. The levels of IL-6 and IL-8 in HGFs were higher when the cells were treated with EBV than when treated with lipopolysaccharide and lipoteichoic acid. EBV induced IκBα degradation, NF-κB transcription, and RAW264.7 cell differentiation into osteoclast-like cells. These findings suggest that even without infecting the cells, EBV contributes to inflammatory cytokine production and osteoclast differentiation by contact with oral cells or macrophage lineage, resulting in periodontitis onset and progression.

Microbiome-mediated incapacitation of interferon lambda production in the oral mucosa

Here, we show that Porphyromonas gingivalis (Pg), an endogenous oral pathogen, dampens all aspects of interferon (IFN) signaling in a manner that is strikingly similar to IFN suppression employed by multiple viral pathogens. Pg suppressed IFN production by down-regulating several IFN regulatory factors (IRFs 1, 3, 7, and 9), proteolytically degrading STAT1 and suppressing the nuclear translocation of the ISGF3 complex, resulting in profound and systemic repression of multiple interferon-stimulated genes. Pg-induced IFN paralysis was not limited to murine models but was also observed in the oral tissues of human periodontal disease patients, where overabundance of Pg correlated with suppressed IFN generation. Mechanistically, multiple virulence factors and secreted proteases produced by Pg transcriptionally suppressed IFN promoters and also cleaved IFN receptors, making cells refractory to exogenous IFN and inducing a state of broad IFN paralysis. Thus, our data show a bacterial pathogen with equivalence to viruses in the down-regulation of host IFN signaling.

Masulili SL, Soeroso Y, Djoko Santoso W, S. Kusdhany L. Association between Epstein-Barr virus and periodontitis: A meta-analysis

Purpose

Previous studies have found that Epstein-Barr virus (EBV) is associated with periodontitis, though some controversy remains. This meta-analysis aimed to clarify and update the relationship between EBV and periodontitis as well as clinical parameters.

Methods

A comprehensive search was conducted in the PubMed and Scopus databases in December 2020. Original data were extracted according to defined inclusion and exclusion criteria. Outcomes were analyzed, including overall odds ratios (ORs) and 95% confidence intervals (CIs). A random-effects model was used, and publication bias was assessed by Egger’s and Begg’s tests. Sensitivity analysis was used to evaluate the stability of the outcome.

Results

Twenty-six studies were included in the present meta-analysis, involving 1354 periodontitis patients and 819 healthy controls. The included studies mostly showed high quality. The overall quantitative synthesis for the association between EBV and periodontitis was an increased odds ratio when subgingival EBV was detected OR = 7.069, 95% CI = 4.197–11.905, P<0.001). The results of subgroup analysis suggested that the association of EBV with periodontitis was significant in Asian, European, and American populations (P<0.001; P = 0.04; P = 0.003, respectively) but not in African populations (P = 0.29). Subgroup analysis by sample type showed that subgingival plaque (SgP), tissue and gingival crevicular fluid GCF were useful for EBV detection (P<0.001). EBV detection amplification methods included nested PCR, multiplex PCR and PCR (P<0.001; P = 0.05, P<0.001, respectively), but EBV detection by real-time PCR and loop-mediated isothermal amplification presented no significant result (P = 0.06; P = 0.3, respectively). For the clinical parameters of periodontitis, pocket depth (PD) and bleeding of probing (BOP) percentages were higher in the EBV-positive sites than in the EBV-negative sites (MD 0.47 [0.08, 0.85], P = 0.02; MD 19.45 [4.47, 34.43], P = 0.01).

Conclusions

A high frequency of EBV detection is associated with an increased risk of periodontitis. The EBV association was particularly significant in all populations except in African populations. Subgigival plaque (SgP), tissue and GCF were not significantly different useful material for detecting EBV in periodontitis. Nested PCR and multiplex PCR are reliable methods for this purpose. In the presence of EBV, PD and BOP are reliable clinical parameters for gingival inflammation. However, some caution in such interpretation is justified due to heterogeneity among studies. A suggested extension could assess the parallel influence of other human herpesviruses.

The human oral virome: Shedding light on the dark matter

Mediators of the initiation, development, and recurrence of periodontitis include the oral microbiome embedded in subgingival plaque and the host immune response to a dysbiosis within this dynamic and complex microbial community. Although mediators have been studied extensively, researchers in the field have been unable to fully ascribe certain clinical presentations of periodontitis to their nature. Emergence of high-throughput sequencing technologies has resulted in better characterization of the microbial oral dysbiosis that extends beyond the extensively studied putative bacterial periodontopathogens to a shift in the oral virome composition during disease conditions. Although the biological dark matter inserted by retroviruses was once believed to be nonfunctional, research has revealed that it encodes historical viral-eukaryotic interactions and influences host development. The objective of this review is to evaluate the proposed association of herpesviruses to the etiology and pathogenesis of periodontal disease and survey the highly abundant prokaryotic viruses to delineate their potential roles in biofilm dynamics, as well as their interactions with putative bacterial periodontopathogens and eukaryotic cells. The findings suggest that potential novel periodontal therapies targeting or utilizing the oral virome can alleviate certain clinical presentations of periodontitis. Perhaps it is time to embrace the viral dark matter within the periodontal environment to fully comprehend the pathogenesis and systemic implications of periodontitis.

ANR, Srinivasan S, Reda R, Testarelli L, Patil S. Role of Periodontal Bacteria, Viruses, and Placental mir155 in Chronic Periodontitis and Preeclampsia-A Genetic Microbiological Study

Previous studies assessed the involvement and impact of periodontal bacteria in preeclamptic women with chronic periodontitis. To explore further, the current study aimed to associate periodontal viruses and bacteria with mir155 levels in placental tissues of preeclamptic women with generalized chronic periodontitis. Four-hundred 45 pregnant women, 18-35 years of age, were selected and divided into four groups (controls, A, B, and C) where the Controls included 145 systemically and periodontally healthy pregnant women Group A-100 systemically healthy pregnant women with chronic periodontitis, Group B- 100 preeclamptic women with chronic periodontitis, Group C- 100 preeclamptic women without chronic periodontitis. Age, BMI, SES, and periodontal parameters such as PI, BOP, PPD, and CAL were noted. Periodontal pathogens such as Tf, Td, Pg, Pi, Fn, HSV, EBV, and HCMV were tested in subgingival plaque, placental tissues, and mir155. We observed that PI, BOP, PPD, CAL, Tf, and EBV were highly significant in Group B. We found a higher number of periodontal bacteria, viruses, and mir 155 in Group B showing a higher risk of preeclampsia. More genetic studies in this field are advised to ascertain the role of periodontopathogens and mir 155 in preeclampsia and periodontal inflammation. What is already known on this subject? Periodontal diseases pose an increased risk of developing preeclampsia and delivering preterm and/or low-birth-weight babies. What do the results of this study add? Periodontal variables such as PI, pocket depth, BOP, and clinical attachment levels, were found to be increased in the preeclamptic women with chronic periodontitis. The significant difference was seen in the relative fold expression of mir155 with higher gene expression of mir155 in groups B and A as compared to group C and controls. What are the implications of these findings for clinical practice and/or further research? In our study, mir155 correlation with the periodontal parameters and periodontal pathogens further strengthen the evidence of periodontal inflammation as a risk of preeclampsia in pregnant women especially when associated with chronic periodontitis. mir155 can be considered to be one of the genetic biomarkers and can be used as a diagnostic tool for the early detection of PE.

Butyric Acid in Saliva of Chronic Periodontitis Patients Induces Transcription of the EBV Lytic Switch Activator BZLF1: A Pilot Study

BACKGROUND/AIM

Epstein-Barr virus (EBV) associates with human chronic periodontitis (CP) progression. We previously demonstrated that butyric acid (BA), produced by periodontopathic bacteria, induced EBV lytic switch activator BZLF1 expression. We investigated whether short chain fatty acids (SCFAs) in CP patients' saliva enabled EBV reactivation.

MATERIALS AND METHODS

Saliva was collected from seven CP patients and five periodontally healthy individuals. SCFAs were quantified using HPLC. BZLF1 mRNA and its pertinent protein ZEBRA were determined with Real-time PCR and western blotting. Histone H3 acetylation (AcH3) was further examined.

RESULTS

BZLF1 mRNA expression and transcriptional activity in EBV-infected Daudi cells were induced only when treated with the CP saliva. Among SCFAs, BA alone correlated significantly with the BZLF1 transcription (r=0.88; p<0.02). As expected, CP patients' saliva induced AcH3.

CONCLUSION

BA in saliva may play a role in EBV reactivation and hence contribute to EBV-related disease progression in CP patients.

Periodontal tissues are targets for Sars-Cov-2: a post-mortem study

Background: The ability of coronavirus SARS-CoV-2 to spread is one of the determinants of the COVID-19 pandemic status. Until June 2020, global COVID-19 cases surpassed 10 million. Asymptomatic patients, with no respiratory impairment, are believed to be responsible for more than 80% of the transmission. Other viruses have been consistently detected in periodontal tissues. Objective: The aim of this study was to investigate the presence of SARS-CoV-2 in periodontal tissue. Methods: We conducted video-endoscope minimally invasive post-mortem biopsy in seven fatal cases of COVID-19, using a regular endoscope video system associated with a smartphone to locate periodontal tissue. We analyzed the samples using RT-PCR, to identify the SARS-CoV-2 RNA and histopathological analysis. Results: The seven studied autopsies with positive laboratory tests for COVID-19 included 57.14% of female patients at the average age of 47.4 (range 8 to 74). In five cases, periodontal tissue was positive for SARS-CoV-2 (RT-PCR). Histopathologic analyses showed morphologic alterations in the keratinocytes of the junctional epithelium, a vacuolization of the cytoplasm and nucleus and nuclear pleomorphism. Conclusion: We presented a biomolecular analysis obtained from minimally invasive autopsies. This is the first study to demonstrate the presence of SARS-CoV-2 in periodontal tissue in COVID-19 positive patients.

Periodontal pockets: A potential reservoir for SARS-CoV-2?

Periodontal pockets are the major clinical manifestation of Periodontitis, a chronic inflammatory oral disease affecting the teeth-supporting tissues and has high prevalence in the adult population. Periodontal pockets are ideal environments for subgingival bacterial biofilms, that interact with the supragingival oral cavity, mucosal tissues of the pocket and a peripheral circulatory system. Periodontal pockets have been found to harbor viral species such as the Herpes simplex viruses' family. Recently, the SARS-CoV-2 has gained major interest of the scientific/medical community as it caused a global pandemic (Covid-19) and paralyzed the globe with high figures of infected people worldwide. This virus behavior is still partially understood, and by analyzing some of its features we hypothesized that periodontal pocket could be a favorable anatomical niche for the virus and thus acting as a reservoir for SARS-CoV-2.

Occurrence and quantification of Anelloviruses and Herpesviruses in gingival tissue in Chinese Shanghai sub-population

Background

Herpesviruses and bacteria and their interplay have long been believed to play important roles in the pathogenesis of periodontitis, but other microbial entities in the oral environment might also be involved. Anelloviruses are commonly detected in human, including in oral samples. The aim of the present study was to explore the occurrence and co-occurrence of human cytomegalovirus (HCMV), Epstein–Barr virus (EBV), and human anelloviruses (HTTVs) in gingival tissue samples collected from participants recruited in Shanghai, China.

Methods

Gingival tissues were collected from 159 participants (57 with aggressive periodontitis (AP), 59 with chronic periodontitis (CP) and 43 with healthy periodontal status). The presence of HCMV, EBV, torque teno virus (TTV), torque teno mini virus (TTMV) and torque teno midi virus (TTMDV) DNA was detected by nested-PCR. The virus loads were quantified by real-time PCR.

Results

The detection rates of EBV, TTV, TTMV and TTMDV were significantly higher in the AP and CP groups compared to the healthy group (all P < 0.01). A statistically significant association was found between EBV, TTV and TTMV virus load and periodontitis (all P < 0.05). Participants infected with EBV showed significantly higher infection rates and higher virus loads of TTV and TTMV than the EBV-negative group (all P < 0.05). The coexistence rates of EBV and anelloviruses and the coexistence of three HTTVs were significantly higher in AP and CP groups (all P < 0.01).

Conclusions

Collectively, results obtained in this study suggest that HTTVs and the coexistence of EBV and HTTVs in particular, may be associated with periodontitis. Possible mechanisms of the interaction between herpesviruses and anelloviruses in the context of periodontitis require further investigation.

EBV LMP1 in Gingival Epithelium Potentially Contributes to Human Chronic Periodontitis via Inducible IL8 Production

BACKGROUND/AIM

Human chronic periodontitis is a major health problem. Although some oral bacteria have been reported to be putative pathogens, Epstein-Barr virus (EBV) is reported to be associated with the progression of periodontitis. However, the role of EBV in the aetiology of periodontitis is unknown. Therefore, we investigated periodontal pathogenesis of EBV to confirm whether EBV-encoded latent membrane protein 1 (LMP1) induces Interleukin-8 (IL8) production in human gingival cells.

MATERIALS AND METHODS

Real-time polymerase chain reaction, luciferase assay, enzyme-linked immunosorbent assay (ELISA), and western blotting were performed for determining IL8 mRNA expression, nuclear factor kappa B (NF-ĸB) transcription, IL8 production, and the phosphorylation of NF-ĸB p65 and Inhibitor of kappa B alpha (IĸBα), respectively, in Ca9-22 human gingival epithelial cells. Two LMP1 mutants lacking C-terminal activating region (CATR) domains responsible for activating NF-ĸB were used.

RESULTS

Extremely high IL8 production was induced by LMP1 in time- and dose-dependent manner, where simultaneous phosphorylation of NF-κB p65 and IĸBα and transcription of NF-ĸB were observed. On the contrary, IL8 production and NF-ĸB transcription were drastically inhibited by dominant negative mutant of IĸBα. Moreover, the LMP1 mutants failed to induce IL8 production.

CONCLUSION

Our findings suggest that due to CATR domains, LMP1 contributes to the progression of periodontitis via IL8 production attributable to NF-ĸB activation.

How Does Epstein-Barr Virus Contribute to Chronic Periodontitis?

Chronic periodontitis is spreading worldwide and mutually interacts with systemic diseases like diabetes mellitus. Although periodontopathic bacteria are inevitable pathogens in their onset and progression, many cases are not ascribable to the virulence of these bacteria because the effect of plaque control is limited. In contrast, Epstein-Barr virus (EBV) in the periodontium has been correlated with chronic periodontitis and has recently been considered as a promising pathogenic candidate for this disease. However, several important questions have yet to be addressed. For instance, although EBV latently infects more than 90% of individuals over the world, why do patients with chronic periodontitis exclusively harbor progeny EBV in the oral cavity? In addition, how does latently infected or reactivated EBV in the periodontium relate to the onset or progression of chronic periodontitis? Finally, is periodontitis incurable because EBV is the pathogen for chronic periodontitis? In this review, we attempt to answer these questions by reporting the current understanding of molecular relations and mechanisms between periodontopathic bacteria and EBV reactivation in the context of how this relationship may pertain to the etiology of chronic periodontitis.

Epstein-Barr virus-infected plasma cells in periodontitis lesions

Growing evidence supports that the Epstein-Barr virus (EBV) is a putative periodontal pathogen, but little is known regarding EBV behavior in periodontitis. Here, EBV infection was monitored in saliva and periodontal pocket (PP), at baseline and 3 months after periodontal non-surgical therapy (p-NST) in 20 patients diagnosed with periodontitis. After the treatment, the patients with the improved periodontal condition (good responders) showed a significant decrease in salivary EBV load. In contrast, in poor responders, EBV load was slightly increased. Moreover, after the therapy, most patients showed clear signs of EBV infection in a deep PP (≥5 mm) selected as a study site. To investigate how EBV can persist in a PP, we further investigate cellular sites of viral replication in PP. We identified large amounts of infiltrated EBV-infected cells, mostly overlapping with CD138⁺ plasma cells (PC). EBV-infected PCs formed high-density clusters within the infiltrate and along the periodontal epithelium which were commonly associated with CD3⁺ T-cells and CD20⁺ B-cells to evoke diffuse ectopic lymphoid-like structures. Taking together, this study provides new insights to support a model where the periodontal condition may play a major role in oral EBV shedding. Since PC harbors the late productive phases of EBV replication, the periodontal condition may favor B-cell differentiation with possible amplification of periodontal EBV infection and viral spreading. PCs have long been recognized as pathogenic markers in inflammatory lesions. Our finding sheds new light on the role of EBV infection and PC in periodontitis.

A brief history of periodontics in the United States of America: Pioneers and thought-leaders of the past, and current challenges

This paper summarizes historical events in periodontology in the United States over the past 200 years. The contributions of some of the key thought-leaders of the past are highlighted. Throughout the 20th century, the evolution of thought, leading to the views currently held regarding the pathogenesis and treatment of periodontal diseases, was significantly influenced by: (1) major changes in health-care education; (2) the emergence of periodontics as a specialty of dentistry; (3) the publication of peer-reviewed journals with an emphasis on periodontology; (4) formation of the National Institute of Dental and Craniofacial Research (NIDCR); and (5) expansion of periodontal research programs by the NIDCR. The two major future challenges facing periodontal research are development of a better understanding of the ecological complexities of host-microbial interactions in periodontal health and disease, and identification of the relevant mechanisms involved in the predictable regeneration of damaged periodontal tissues.

Periodontal herpesvirus morbidity and treatment

Four billion individuals worldwide have a history of periodontitis, with the poorest people in society most affected. Periodontitis can lead to unsightly drifting of teeth and tooth loss that may interfere with the wellbeing of daily living and has also been linked to at least 57 medical diseases and disabilities. The etiology of severe periodontitis includes active herpesviruses, specific bacterial pathogens, and destructive immune responses, but herpesviruses seem to be the major pathogenic determinant. Periodontal herpesviruses that disseminate via the systemic circulation to nonoral sites may represent a major link between periodontitis and systemic diseases. Current treatment of periodontitis focuses almost exclusively on bacterial biofilm and will require revision. Periodontal therapy that targets both herpesviruses and bacterial pathogens can provide long-term clinical improvement and potentially reduces the risk of systemic diseases. Molecular diagnostic tests for periodontal pathogens may enable early microbial identification and preemptive therapy. This review details an efficient and reliable anti-infective treatment of severe periodontitis that can be carried out in minimal time with minimal cost.

mRNA expression of IFN-λs in the gingival tissue of patients with chronic or aggressive periodontitis: A polymerase chain reaction study

BACKGROUND

Several studies have proven the existence of herpesviruses in periodontal pockets of patients with chronic or aggressive periodontitis. Recently discovered interferon lambda (IFN-λ) has antiviral properties and is induced by herpesviruses. The present study was a quantitative analysis of messenger RNA (mRNA) expression of IFN-λs (IFN-λ1, IFN-λ2, IFN-λ3) in the gingival tissues of patients with chronic or aggressive periodontitis.

METHODS

A total of 90 participants (50 men and 40 women; age range 19-50 years, mean age 31.50 ± 7.8) were categorized into three groups: healthy participants, patients with chronic periodontitis, and patients with aggressive periodontitis. mRNA expression of IFN-λs in gingival tissues was estimated using reverse transcriptase polymerase chain reaction and was correlated with clinical parameters such as gingival index (GI), probing pocket depth (PPD), and clinical attachment level (CAL).

RESULTS

mRNA of IFN-λ1, IFN-λ2, and IFN-λ3 was expressed in gingival tissues of healthy participants and in patients with chronic or aggressive periodontitis. The highest level of IFN-λ1 was observed in patients with aggressive periodontitis (3.049 ± 9.793), whereas IFN-λ2 (4.322 ± 11.310) and IFN-λ3 (11.932 ± 27.479) were highest in patients with chronic periodontitis. The difference in mRNA expression of IFN-λ1 (P = 0.008) and IFN-λ3 (P = 0.043) among three groups was statistically significant CONCLUSION: Increased quantity of IFN-λs in patients with chronic and patients with aggressive periodontitis suggests a role in periodontitis. Variation in the expression of IFN-λ1 and IFN-λ3 in patients with periodontitis needs to be further evaluated. The mRNA expression of antiviral IFN-λs in gingival tissues might enhance our understanding related to viral pathogenesis of periodontal diseases.

Role of herpesviruses in chronic periodontitis and their association with clinical parameters and in increasing severity of the disease

Objective:

This study aims to assess the role of herpesviruses in chronic periodontitis and their association with clinical parameters and in increasing severity.

Materials and Methods:

This was a prospective case–control study. Ethical approval and prior consent were taken. A subgingival plaque sample was collected from a total of 300 patients and 300 controls and processed for DNA extraction and multiplex polymerase chain reaction for detection of herpesviruses.

Results:

The most predominant age group affected was 41–50 followed by 31–40 years and male patients outnumbered the female patients. Herpes simplex virus (HSV)-1 (46.6%) was the most common Herpesvirus followed by HSV-2 (34.6%), Epstein–Barr viruses (EBV) (30.6%), and cytomegalovirus (CMV) (19.3%) in chronic periodontitis. Herpesviruses were significantly associated with increasing severity of the disease and had shown differences in their association with clinical parameters. Multiple herpesvirus infection was seen in patients with severe chronic periodontitis. The most common combination was HSV-1 + HSV-2 and HSV-1 + HSV-2 + EBV.

Conclusions:

HSV-1 was the most common herpesviruses implicated in the etiology of the chronic periodontitis followed by HSV-2, EBV and CMV. A herpesvirus differs in association with clinical parameters and plays an important role in increasing severity of the disease.

Genetic variations of TLRs and their association with HPV/EBV, co-infection along with nicotine exposure in the development of premalignant/malignant lesions of the oral cavity in Indian population

BACKGROUND

Despite being most preventable malignancies associated with smoked and smokeless tobacco products, squamous cell carcinoma of oral cavity is one of the most common malignancy in India. The aim of the present study was to evaluate the role of TLRs in oral pre-cancerous, cancerous cases and their genotypic correlation with HPV/EBV, co-infection & lifestyle habits in Indian population.

METHODS

The present study was conducted on 300 subjects (100 OSCC, 50 pre-cancer & 150 controls). The amplification of TLRs gene and HPV/EBV co-infection was assessed by Nested PCR, PCR-RFLP and further confirmation by direct sequencing.

RESULTS

The TLR 9(-1486 T/C), revealed that the TT vs. CT + CC genotype had a ˜5-fold increased risk for the development of pre-cancerous lesions as compared to controls (p = 0.0001). Further analysis showed that the risk of cancer was extremely pronounced in HPV/EBV, co-infection (p = 0.0141), implicating the possible interaction between TLR 9(-1486T/C) genotype and HPV infection in increasing cancer/pre-cancer risk. The 'G' allele of TLR 4(+896A/G) was also a higher risk of developing pre-cancerous lesions with 4.5 fold and statistically significant (p = 0.0001). The genotypic association of TLR 9(-1486T/C) in OSMF cases showed ˜8 fold increased risk and TLR 4(+896A/G) showed fourteen fold higher risk for leukoplakia (p < 0.0001, OR = 14.000).

CONCLUSION

Genetic polymorphism of TLR 9(-1486 T/C) and TLR 4(+896A/G) may influence the effects of HPV/EBV, co-infection and play the significant role in development of the disease. The significance of these TLRs seemed to be enhanced by tobacco chewing and smoking habits also, which act as an important etiological risk factor for OSCC.

Herpesviruses and MicroRNAs: New Pathogenesis Factors in Oral Infection and Disease?

The oral cavity incessantly encounters a plethora of microorganisms. Effective and efficient oral innate and adaptive immune responses are incumbent to maintain healthy mucosa. A higher prevalence of Human Herpesviruses (HHV), a family of large enveloped DNA viruses, has been reported in multiple oral inflammatory diseases suggesting their involvement in disease progression. However, the viral components contributing to oral disease remain obscure. MicroRNAs (miRNA) are non-protein coding, single stranded ribonucleic acid (RNA) molecules that post-transcriptionally regulate diverse messenger RNAs. Thus, miRNAs can control large repertoire of biological processes. Changes in miRNA expression are associated with various oral infections and diseases. Cellular miRNAs can act as pro- or anti-viral factors and dysregulation of host miRNA expression occurs during herpesviruses infection. This strongly suggest a critical role of cellular miRNAs in host-herpesvirus interaction. Interestingly, HHV also encode multiple miRNAs (called viral miRNAs) that may play key role in host-pathogen interaction by modulating both host biological pathways and controlling viral life cycle. Recent studies from our laboratory have identified viral miRNAs (v-miRs) in diseased oral tissue biopsies and demonstrate their immunomodulatory roles. This review discusses the association of miRNAs (both host and viral) and herpesviruses in the pathogenesis of oral inflammatory diseases.

Detection of Virus Herpes Simplex Type 1 in Patients with Chronic Periodontal Disease

BACKGROUND

Periodontal disease is an inflammatory-destructive condition of the supporting tissues of the teeth. Microorganisms found in the dental plaque were considered to be the primary local etiologic factor responsible for the periodontal destruction. It is also evident that herpes simplex viruses may have an impact in the etiopathogenesis of periodontal disease.

AIM

This study has been made with the aim to analyse the prevalence of herpes simplex virus type 1 (HSV-1) in the dental plaque (supra- and subgingival) of patients with the chronic periodontal disease.

MATERIAL AND METHODS

The study comprised a total of 89 patients with chronic periodontal disease divided into two groups (patients with moderate and severe periodontitis). Supragingival dental plaque samples were taken with sterile cotton (supragingival), and subgingival dental plaque samples were taken with paper absorbents. Samples were subjected to extraction of DNA and further analysis with multiplex PCR for the presence of herpes viral DNA.

RESULTS

HSV-1 virus was detected In 24.7% of all patients included in the study. HSV-1 was detected in 22.2% of patients with the moderate stage of the disease, of which in all (100%) in the supragingival plaque samples and only 16.7% in subgingival plaque samples. In two patients HSV-1 was concomitantly detected in supra and subgingival plaque samples. In patients with advanced stage of the disease, the HSV-1 virus was detected in 28.6% patients. In two of the patients, HSV-1 was concomitantly detected in supra and subgingival plaque samples. Statistically, a significant difference was found in HSV-1 positive patients with a moderate stage of disease, between the presence of the virus in subgingival (100%) and subgingival (16.7%) dental plaque samples, p < 0.05.

CONCLUSION

Herpes simplex viruses type 1 are present in supragingival and subgingival dental plaque.

The Periodontium as a Potential Cause of Orofacial Pain: A Comprehensive Review

Introduction:

Orofacial pain of periodontal origin has a wide range of causes, and its high prevalence and negative effect on patients' quality of life make intervention mandatory. This review provides a periodontological overview of the field of orofacial pain, focusing on the entities which involve the periodontal tissues and may be the cause of this pain or discomfort.

Methods:

The study comprised a literature search of these pathologies conducted in the MEDLINE/PubMed Database. Acute infectious entities such as gingival and periodontal abscesses are emergencies that require a rapid response. Periodontitis associated with endodontic processes, necrotizing periodontal disorders, desquamative gingivitis, gingival recession, and mucogingival herpetic lesions, cause mild to severe pain due to tissue destruction and loss. Other lesions that lead to periodontal discomfort include gingival enlargement and periodontal ligament strains associated with occlusal trauma, parafunctional habit and the impaction of food or foreign bodies.

Conclusion:

A range of therapeutic, pharmacological and surgical alternatives are available for the management of these injuries. However, the wide variety of causes of orofacial pain or periodontal discomfort may confuse the clinician during diagnosis and may lead to the wrong choice of treatment.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

Herpesvirus-encoded microRNAs detected in human gingiva alter host cell transcriptome and regulate viral infection

MicroRNAs (miRNAs) are small, non-coding RNAs of ~18-25 nucleotides that have gained extensive attention as critical regulators in complex gene networks including immune cell lineage commitment, differentiation, maturation, and maintenance of immune homeostasis and function. Many viruses encode miRNAs that directly downregulate the expression of factors of the innate immune system, which includes proteins involved in promoting apoptosis and recruitment. In this study, we examined the expression profiles of three previously identified viral miRNAs (v-miRs) from the human herpesvirus (HHV) family, HSV-1 (miR-H1), KSHV (miR-K12-3-3p), and HCMV (miR-US4) in healthy and diseased periodontal tissues and observed increased levels of v-miRs in diseased tissues. To understand the significance of this increase, we overexpressed v-miRs in human oral keratinocytes (HOK), a common target for various HHV, and analyzed the impact of miR-H1 and miR-K12-3-3p on the host transcriptome. More than 1300 genes were altered in HOK overexpressing miR-H1 and miR-K12-3-3p. Global pathway analysis of deregulated genes identified several key cellular pathways that may favor viral persistence. Using bioinformatic analysis, we predicted hundreds of potential v-miR binding sites on genes downregulated by miR-H1 and miR-K12-3-3p and validated three novel target v-miR sites suggesting widespread direct and indirect modulation of numerous host genes/pathways by a single v-miR. Finally, in vitro HSV-1 infection assays showed that miR-H1 can regulate viral entry and infection in human oral keratinocytes (HOK). Overall, our results demonstrate clinical and functional relevance of pathogenic viral molecules viz., v-miRs that regulate both host and viral functions and may contribute to the pathogenesis of inflammatory oral diseases.

Epstein-Barr virus is associated with periodontal diseases: A meta-analysis based on 21 case-control studies

Some controversies still exist between the detection of Epstein-Barr virus (EBV)'s DNA and risks of periodontal diseases. Hence, a comprehensive meta-analysis on all available literatures was performed to clarify the relationship between EBV and preidontitis.A comprehensive search was conducted within the PUBMED, EMBASE, and WANFANG databases up to October 10th, 2016 according to inclusion and exclusion criteria and finally 21 case-control literatures were obtained. The outcomes including odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Publication bias was determined by Begg or Egger test. Sensitivity analysis was used to investigate reliability and stability of the results.According to the data from included trials, the association between overall increased risks of periodontitis and the detection of EBV was significant (OR = 6.199, 95% CI = 3.119-12.319, P < 0.001). In the disease-type analysis, the pooled ORs for chronic periodontitis and aggressive periodontitis were 6.586 (95% CI = 3.042-14.262, P < 0.001) and 8.361 (95% CI = 2.109-33.143, P = 0.003), respectively. In the subgroup analysis of ethnicity, our results suggested that high EBV-detecting frequencies were correlated with increased risks of periodontitis in Asians, Europeans, and Americans (P < 0.001). Subgroup analysis by the sample type showed that subgingival plaque (SgP) samples and tissue samples were available for EBV detecting (P < 0.001). Detecting EBV of samples in ≥5 (6) mm sites of periodontal pockets were easier than in ≤3-mm sites (P = 0.023).This meta-analysis indicates that high frequent detection of EBV correlates with increased risk of periodontal diseases. SgP and tissue are available for detecting EBV in patients of periodontitis. At last, our results suggest that detecting EBV of samples in =5 (6) mm sites of periodontal pockets are more sensitive than in ≤3-mm sites.

Putative periodontopathic bacteria and herpesviruses in pregnant women: a case-control study

Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis [Pg], Aggregatibacer actinomycetemcomitans [Aa], Fusobacterium nucleatum [Fn], Prevotella intermedia [Pi], Tannerella forsythia [Tf], and Treponema denticola [Td]) and three herpesviruses (Epstein-Barr virus [EBV], human cytomegalovirus [HCMV], and herpes simplex virus [HSV]) were detected. Socio-demographic data and oral health related behaviors, and salivary estradiol and progesterone levels were also collected. The results showed no significant differences in socio-demographic background, oral health related behaviors, and salivary estradiol and progesterone levels between the two groups (all P > 0.05). The detection rates of included periodontopathic microorganisms were not significantly different between the two groups (all P > 0.05), but the coinfection rate of EBV and Pg was significantly higher in the case group than in the control group (P = 0.028). EBV and Pg coinfection may promote the development of chronic periodontitis among pregnant women.

Host response mechanisms in periodontal diseases

Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4⁺ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that presents a significantly host immune and inflammatory response to the microbial challenge that determine of susceptibility to develop the destructive/progressive periodontitis under the influence of multiple behavioral, environmental and genetic factors.

Acute periodontal lesions

This review provides updates on acute conditions affecting the periodontal tissues, including abscesses in the periodontium, necrotizing periodontal diseases and other acute conditions that cause gingival lesions with acute presentation, such as infectious processes not associated with oral bacterial biofilms, mucocutaneous disorders and traumatic and allergic lesions. A periodontal abscess is clinically important because it is a relatively frequent dental emergency, it can compromise the periodontal prognosis of the affected tooth and bacteria within the abscess can spread and cause infections in other body sites. Different types of abscesses have been identified, mainly classified by their etiology, and there are clear differences between those affecting a pre-existing periodontal pocket and those affecting healthy sites. Therapy for this acute condition consists of drainage and tissue debridement, while an evaluation of the need for systemic antimicrobial therapy will be made for each case, based on local and systemic factors. The definitive treatment of the pre-existing condition should be accomplished after the acute phase is controlled. Necrotizing periodontal diseases present three typical clinical features: papilla necrosis, gingival bleeding and pain. Although the prevalence of these diseases is not high, their importance is clear because they represent the most severe conditions associated with the dental biofilm, with very rapid tissue destruction. In addition to bacteria, the etiology of necrotizing periodontal disease includes numerous factors that alter the host response and predispose to these diseases, namely HIV infection, malnutrition, stress or tobacco smoking. The treatment consists of superficial debridement, careful mechanical oral hygiene, rinsing with chlorhexidine and daily re-evaluation. Systemic antimicrobials may be used adjunctively in severe cases or in nonresponding conditions, being the first option metronidazole. Once the acute disease is under control, definitive treatment should be provided, including appropriate therapy for the pre-existing gingivitis or periodontitis. Among other acute conditions affecting the periodontal tissues, but not caused by the microorganisms present in oral biofilms, infectious diseases, mucocutaneous diseases and traumatic or allergic lesions can be listed. In most cases, the gingival involvement is not severe; however, these conditions are common and may prompt an emergency dental visit. These conditions may have the appearance of an erythematous lesion, which is sometimes erosive. Erosive lesions may be the direct result of trauma or a consequence of the breaking of vesicles and bullae. A proper differential diagnosis is important for adequate management of the case.

Prevalence of Herpesvirus and Correlation with Clinical Parameters in Indian Subjects with Chronic Periodontitis

OBJECTIVE

The identification of new uncultured species and viruses supports the possibility of combination of the herpes-virus-bacterial periodontal infection for periodontitis. The paucity of data and studies with larger sample size in Indian subjects provides an unclear picture of the presence of the herpesvirus in this population.

MATERIALS AND METHODS

This was a cross-sectional study consisting of 100 each in the healthy group and chronic periodontitis (CP) group. The subgingival plaque was collected and polymerase chain reaction was performed post deoxyribonucleic acid (DNA) extraction by using specific primers for human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The data were analyzed using Fisher's exact test, Mann-Whitney U test and Spearman's coefficient correlation.

RESULTS

Human cytomegalovirus and EBV viruses were significantly higher in the CP group as compare to the healthy group. A higher percentage of those with CMV positive had EBV also positive (28.3%) compared to only 9.1% of CMV negative being EBV positive in the CP group. When both the healthy and CP group in total was compared, there was a significant correlation with all clinical parameters.

CONCLUSION

Both the viruses dominated in disease as compared to health were similar to the earlier findings. The CP group had higher pocket depth and clinical attachment loss in the virus positive subjects. These findings could suggest that virus serves as a prelude to the disease and the combination of the two viruses could play a role in the pathogenesis.

Epstein-Barr virus in the enlarged salivary tissues of patients with IgG4-related disease

OBJECTIVE

Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized disease entity characterized by high-serum IgG4 concentration and IgG4-producing plasma cell production with fibrotic or sclerotic changes in affected organs. We aimed to clarify the roles of Epstein-Barr virus (EBV) in patients with IgG4-RDs.

STUDY DESIGN AND SETTING

A retrospective clinical study at the Yamagata University School of Medicine, Yamagata, Japan.

METHODS

The patient group consisted of four males and four females with an average age of 62 years (range: 48-73). Expression of IgG4, latent member protein 1, EBV nuclear antigens-2, and EBV-encoded RNA in affected salivary glands from patients with IgG4-RD was examined by using immunohistochemistry and in situ hybridization. The copy number of EBV DNA in the salivary glands was also investigated by real-time polymerase chain reaction.

RESULTS

All patients had hard masses in the salivary or lacrimal glands, or both, bilaterally. Serum concentrations of IgG4 were elevated in all cases (mean 589.1, range 129-1750), and IgG4-positive plasmacytes were observed in the involved salivary glands. Four patients developed potentially life-threatening systemic involvement after initial salivary gland swelling. EBV-associated molecules (EBNA and EBER) were overexpressed in the affected salivary glands. The copy number of EBV DNA was significantly higher in patients with potentially life-threatening systemic involvement than in patients without systemic involvement (P < 0.05).

CONCLUSION

These results suggest that the copy number of EBV DNA could be useful as diagnostic findings in IgG4-RD to predict potentially life-threatening systemic involvement.

LEVEL OF EVIDENCE

4.

Association of Herpes Viruses with Mild, Moderate and Severe Chronic Periodontitis

INTRODUCTION

Periodontal disease is an inflammatory condition of the supporting tissues of the teeth. It is a multi-factorial and multi-etiological infectious disease process. Recent evidences shows that human herpes viruses could be putative pathogens. The aim of the present study was to evaluate the association of Herpes viruses especially Herpes simplex viruses (HSV-1 and 2), Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) in patients with chronic periodontitis.

MATERIALS AND METHODS

A total of 75 patients with periodontitis were included in the study (25 each with mild, moderate and severe periodontitis) with ethical approval and informed consent. Sub gingival plaque sample was collected and subjected to extraction of DNA and further analysis with multiplex Polymerase chain reaction for the presence of herpes viral DNA. The collected data was entered in the excel sheet format. It was subjected to statistical analysis using SPSS software. The Chi-Square statistical tests was applied and p-value<0.05 was taken as significant.

RESULTS

The overall association of HSV-1, HSV-2, EBV and CMV was 28%, 32%, 30.66% and 37.33% respectively in the present study from the cases of chronic periodontitis.

CONCLUSION

Epstein Barr viruses were detected from all types of cases of chronic periodontitis in the present study. Though, EBV was not significantly associated with periodontitis; they were significantly increased in severe periodontitis. Herpes viruses were significantly associated with periodontal disease, more so with severe periodontal disease. They could thus be playing a role in increasing the severity of the disease. Therapeutic and prophylactic intervention planned against these viruses could decrease the tooth loss associated with this disease.

Quantification of Epstein-Barr Virus and Human Cytomegalovirus in Chronic Periodontal Patients

Background:

Although studies focused mainly on the identification of periopathogenic bacteria, recent reports have suggested that various herpes viruses may also be involved in the occurrence and progression of different forms of periodontal diseases.

Objectives:

This study aimed to compare the prevalence and load of Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV) in subgingival tissue specimens between chronic periodontitis and healthy sites.

Patients and Methods:

A total of 60 samples from the systematically healthy patients with chronic periodontitis participated in this study (mean age, 35 ± 7). Clinical periodontal evaluation included the plaque index (PI) (Loe and Silness), bleeding on probing (BOP) (O’Leary), bleeding index, periodontal pocket depth (PPD) and clinical attachment level measurement. Tissue specimens harvested from > 6 mm periodontal pockets and from ≤ 3 mm sulcus depth in a quadrant of the same patient using periodontal curettes. Moreover, the unstimulated whole saliva was gathered as a shedding medium. A Taq-man Real-Time Polymerase Chain Reaction assay was used to identify genomic copies of periodontal HCMV and EBV. Data were analyzed by the Wilcoxon-signed ranks and Friedman tests using the SPSS 16 software.

Results:

Out of 60 samples of subgingival tissues taken from the patients with chronic periodontitis, EBV count was the highest in saliva and the least in the tissue sample with PD < 3 mm (P < 0.05). The highest HCMV count was in saliva and tissue samples with PD > 6 mm (P < 0.05).

Conclusions:

According to the results of this study, quantification of HCMV and EBV observed in this study is high in periodontal tissue samples of severe chronic periodontitis.

Chemokine function in periodontal disease and oral cavity cancer

The chemotactic cytokines, or chemokines, comprise a superfamily of polypeptides with a wide range of activities that include recruitment of immune cells to sites of infection and inflammation, as well as stimulation of cell proliferation. As such, they function as antimicrobial molecules and play a central role in host defenses against pathogen challenge. However, their ability to recruit leukocytes and potentiate or prolong the inflammatory response may have profound implications for the progression of oral diseases such as chronic periodontitis, where tissue destruction may be widespread. Moreover, it is increasingly recognized that chronic inflammation is a key component of tumor progression. Interaction between cancer cells and their microenvironment is mediated in large part by secreted factors such as chemokines, and serves to enhance the malignant phenotype in oral and other cancers. In this article, we will outline the biological and biochemical mechanisms of chemokine action in host–microbiome interactions in periodontal disease and in oral cancer, and how these may overlap and contribute to pathogenesis.

Prevalence and quantitative analysis of Epstein-Barr virus DNA and Porphyromonas gingivalis associated with Japanese chronic periodontitis patients

Objective

A number of studies have recently suggested Epstein–Barr virus (EBV) involvement in the pathogenesis of periodontitis. In this study, we investigated the association between major periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) and EBV in Japanese chronic periodontitis (CP) patients.

Materials and methods

A group of 25 patients with CP participated in the study along with 13 individuals without periodontitis. Subgingival samples were obtained with paper points. Quantitative real-time polymerase chain reaction (PCR) was used to detect EBV DNA and P. gingivalis.

Results

In the CP patients, EBV DNA and P. gingivalis were detected in both 80 % of sites with probing pocket depths (PPD) of ≥5 mm and in 40 and 36 % of sites with PPD ≤3 mm, respectively. EBV DNA and P. gingivalis were detected in 50 and 27 % of the sites in periodontally healthy individuals. Coexistence of EBV DNA and P. gingivalis was significantly higher in the deeper PPD sites of CP patients (68 %) than in the PPD sites of the healthy controls (15 %) and shallow PPD sites of CP patients (12 %). PCR-positive deeper PPD sites of CP patients for EBV DNA and P. gingivalis range between 3.74 × 10³∼2.83 × 10⁹ and 2.73 × 10⁵∼6.65 × 10⁹ (copies/ml), respectively.

Conclusion

These results suggest an association between EBV DNA, P. gingivalis, and CP in Japanese individuals. Further studies are required to clarify this association; however, we believe that our enhanced understanding of the pathogenesis of periodontal diseases involving viral infections will lead to new treatments.

Lessons learned and unlearned in periodontal microbiology

Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best-characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host-microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems-biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

Learned and unlearned concepts in periodontal diagnostics: a 50-year perspective

In the past 50 years, conceptual changes in the field of periodontal diagnostics have paralleled those associated with a better scientific understanding of the full spectrum of processes that affect periodontal health and disease. Fifty years ago, concepts regarding the diagnosis of periodontal diseases followed the classical pathology paradigm. It was believed that the two basic forms of destructive periodontal disease were chronic inflammatory periodontitis and 'periodontosis'- a degenerative condition. In the subsequent 25 years it was shown that periodontosis was an infection. By 1987, major new concepts regarding the diagnosis and pathogenesis of periodontitis included: (i) all cases of untreated gingivitis do not inevitably progress to periodontitis; (ii) progression of untreated periodontitis is often episodic; (iii) some sites with untreated periodontitis do not progress; (iv) a rather small population of specific bacteria ('periodontal pathogens') appear to be the main etiologic agents of chronic inflammatory periodontitis; and (v) tissue damage in periodontitis is primarily caused by inflammatory and immunologic host responses to infecting agents. The concepts that were in place by 1987 are still largely intact in 2012. However, in the decades to come, it is likely that new information on the human microbiome will change our current concepts concerning the prevention, diagnosis and treatment of periodontal diseases.

Current status of herpesvirus identification in the oral cavity of HIV-infected children

INTRODUCTION

Some viruses of the Herpesviridae family are frequently the etiologic agents of oral lesions associated with HIV. The aim of this study was to identify the presence of herpes simplex virus types 1 and 2 (HSV-1, HSV-2), Varicella Zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus type 6, type 7 and type 8 (HHV-6, HHV-7 and HHV-8) in the oral cavity of HIV-infected children/adolescents and verify the association between viral subtypes and clinical factors.

METHODS

The cells of oral mucosa were collected from 50 HIV infected children/adolescents, 3-13 years old (mean age 8.66). The majority (66%) of selected were girls, and they were all outpatients at the pediatric AIDS clinic of a public hospital in Rio de Janeiro. Nested-PCR was used to identify the viral types.

RESULTS

Absence of immunosuppression was observed in 66% of the children. Highly active antiretroviral therapy (HAART) was used by 72.1% of selected and moderate viral load was observed in 56% of the children/adolescents. Viral types were found in 86% of the children and the subtypes were: HSV-1 (4%), HSV-2 (2%), VZV (4%), EBV (0%), HCMV (24%), HHV6 (18%), HHV-7 (68%), HHV8 (0%).

CONCLUSIONS

The use of HAART has helped to reduce oral lesions, especially with herpes virus infections. The health professionals who work with these patients should be aware of such lesions because of their predictive value and the herpes virus can be found circulating in the oral cavity without causing lesions.

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.

TLR3 agonist enhances CC chemokine ligand 20 production in IL-1β-stimulated human gingival fibroblasts

Viruses are related to the etiology of periodontitis. However, the role of viruses on Th17 cells infiltration in periodontitis lesions is unknown. Therefore, we examined the effects of TLR3 ligand on CCL20, which is related to Th17 cells migration, production in human gingival fibroblasts (HGFs). Polyinosinic-polycytidylic acid (Poly I:C), which is a TLR3 agonist, stimulation could moderately induce CCL20 production in HGFs. Poly I:C synergistically enhanced CCL20 expression from IL-1β-stimulated HGFs. Inhibitors of p38 MAPK, extracellular signal-regulated kinase (ERK), c-Jun N terminal kinase (JNK), and NF-κB significantly inhibited CCL20 production in Poly I:C/IL-1β-stimulated HGFs. Western blot analysis disclosed phosphorylation of p38 MAPK, JNK, and IκB-α were enhanced in Poly I:C/IL-1β-treated HGFs. These data suggested that virus infection is related to Th17 cells migration in periodontitis lesion to induce CCL20 production in HGFs via TLR3. Therefore, our results indicated that virus might be important pathogen in periodontal disease.

Detection of human herpes viruses in patients with chronic and aggressive periodontitis and relationship between viruses and clinical parameters

BACKGROUND AND AIMS

Recent microbiological researches have revealed the possible role of human cytomegalovirus (HCMV), Epstein barr virus (EBV), and herpes simplex virus (HSV-1 and HSV-2) in the etiopathogenesis of periodontal diseases. The present pilot study has been undertaken to detect the presence of these viruses in chronic periodontitis, aggressive periodontitis, and healthy individuals and to determine the relationship between these viruses and the clinical parameters.

MATERIALS AND METHODS

A total of 10 patients belonging to the age group of 18 to 55 years were included. The patients were randomly assigned into periodontally healthy (sulcus depth ≤ 3 mm), chronic periodontitis, and aggressive periodontitis with pockets measuring ≥6 mm. Seventy-five subgingival plaque samples (25 samples from each group) were collected and subjected to multiplex polymerase chain reaction for the detection of presence of HCMV, EBV, HSV-1, and HSV-2. The results were analyzed using one-way ANOVA for multiple group comparisons followed by Student's t-test for pair-wise comparisons. Categorical data was analyzed by Fisher's exact test.

RESULTS

HSV-1 was detected in 76% (P<0.001) of sites with chronic periodontitis and 80% (P<0.001) sites with aggressive periodontitis. EBV was detected in 32% (P<0.05) of sites with chronic periodontitis and aggressive periodontitis. The probing pocket depth and clinical attachment level was statistically significant in HSV-1 detected sites compared with undetected sites in aggressive periodontitis patients

CONCLUSION

Among these viruses HSV-1 and EBV were found to be significantly associated with destructive periodontal disease, including chronic and aggressive periodontitis. Further, HSV-1 was found to be associated with severity and progression of destructive periodontal disease.

A case of age-related Epstein-Barr virus (EBV)-associated B cell lymphoproliferative disorder, so-called polymorphous subtype, of the mandible, with a review of the literature

Epstein-Barr virus (EBV) is known to be associated with the development of lymphomas in immunocompromised patients. Recently, age-related immune impairment has been recognized as a predisposing factor in the development of EBV-driven lymphoproliferative disorders (LPDs) in elderly patients without any known immunodeficiency or prior lymphoma. In approximately 70% of reported cases, the affected sites have been extranodal, such as the skin, lung, tonsil and stomach. However, age-related EBV-associated B cell (EBV + B cell) LPD is extremely rare in the oral cavity. Here we report a 71-year-old Japanese man who developed an EBV + B cell LPD resembling classical Hodgkin lymphoma (CHL)--so-called polymorphous subtype-of the mandible. Histopathologically, infiltration of large atypical lymphoid cells including Hodgkin or Reed-Sternberg-like cells into granulation tissue with marked necrosis was found in the mandibular bone. Immunohistochemical analysis revealed that the large atypical Hodgkin or Reed-Sternberg-like cells were CD3-, CD15-, CD20+, CD30+ and Epstein-Barr virus (EBV)-latent infection membrane protein-1 (LMP-1)+. In situ hybridization (ISH) demonstrated EBV-encoded small RNA (EBER) + in numerous Hodgkin or Reed-Sternberg-like cells. EBNA-2 was detected by polymerase chain reaction (PCR) using an extract from the formalin-fixed, paraffin-embedded specimen. To our knowledge, this is the first reported case of the polymorphous subtype of age-related EBV + B cell LPD affecting the mandible.

Correlation between different genotypes of human cytomegalovirus and Epstein-Barr virus and peri-implant tissue status

BACKGROUND

The purpose of this study was to estimate the prevalence of different genotypes of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in peri-implantitis and mucositis sites, and to evaluate the correlation between herpesvirus presence and clinical parameters.

METHODS

A total of 80 dental implants (mean time of loading, 4.16 ± 1.8 years) were evaluated during the course of the study (30 peri-implantitis, 25 mucositis and 25 healthy peri-implant sites). The following clinical parameters were assessed: visible plaque index, bleeding on probing, suppuration and probing depth. A polymerase chain reaction (PCR) assay was used to identify the presence of different HCMV and EBV genotypes in peri-implant tissue plaque samples.

RESULTS

HCMV-2 was detected in 53.3% and EBV-1 in 46.6% of the 30 peri-implantitis sites evaluated. By contrast, HCMV-2 was not detected in healthy periodontal sites and EBV-1 was detected in one healthy site. A statistically significant correlation was found between the presence of HCMV-2 and EBV-1 genotypes and clinical parameters of peri-implantitis.

CONCLUSIONS

The results from the present study confirmed the high prevalence of HCMV-2 and EBV-1 in the peri-implant tissue plaque of peri-implantitis sites and suggests a possible active pathogenic role of the viruses in peri-implantitis.

Correlation of cytomegalovirus and human herpesvirus 7 with CD3+ and CD3+ CD4+ cells in chronic periodontitis patients

BACKGROUND AND OBJECTIVE

Human chronic periodontitis is an inflammatory process characterized by dense accumulation of immune cells in the periodontal tissue. The periodontitis can lead to loss of teeth in the patient and the pathogenesis of this disease is not completely known. This study tested the hypothesis that chronic periodontitis-affected sites can harbor betaherpesviruses and that viruses are linked to a profile of the inflammatory infiltrate.

MATERIAL AND METHODS

Biopsies of periodontal tissue were taken from periodontitis-affected patients and from healthy subjects. Immunohistochemistry was performed to count CD19(+) B cells, CD3(+) total T cells, T-CD4(+) and T-CD8(+) cell subsets, and PCR was performed to detect cytomegalovirus and human herpesvirus 6 and 7 in the samples. One slide of each sample was stained with Giemsa for histopathological examination and to evaluate the quality of the cellular infiltrate.

RESULTS

As expected, tissues collected from healthy subjects presented no significant level of inflammatory infiltration and were therefore excluded from immunostaining procedures. Results showed that CD19(+) B cells were in higher number than CD3(+) T cells in the periodontitis-affected tissue, but this was not statistically significant. The T-CD4(+) lymphocyte subset was significantly higher than the T-CD8(+) lymphocyte subset (p = 0.004) in the samples. Cytomegalovirus and human herpesvirus 7 were found at periodontitis-affected sites, but not in tissue collected from healthy subjects (p = 0.04 and p = 0.04, respectively). Human herpesvirus 6 was rarely detected. We found a correlation between cytomegalovirus and lower CD19(+) /CD3(+) ratios (ratio < 0.9, p = 0.003) and between human herpesvirus 7 and lower CD19(+) /CD3(+) ratios (ratio < 0.9, p = 0.003) and higher CD4(+) /CD8(+) ratios (ratio > 1.1, p = 0.002).

CONCLUSION

This study shows that cytomegalovirus and human herpesvirus 7 can be present at periodontitis-affected sites but are uncommon at healthy periodontal sites. Moreover, our data suggest that cytomegalovirus can be related to an inflammatory infiltrate with predominance of CD3(+) T cells, whereas human herpesvirus 7 can be associated with an infiltrate with predominance of T-CD4(+) cells. However, further studies are necessary to support this hypothesis. Herpesviruses could play a role in human chronic periodontitis by modulation of the T cell response.