Relationship between human immunodeficiency virus (HIV-1) infection and chronic periodontitis

Reducing Functional Domain of Histatin 5 Improves Antifungal Activity and Prevents Proteolytic Degradation

Histatin 5 (Hst5) is an antifungal peptide (AFP) naturally produced by parotid glands with strong activity against Candida albicans. One of its mechanisms of action is the generation of reactive oxygen species (ROS) inside the C. albicans cells. Despite being an important peptide for the human innate immune response, its activity is reduced or inactivated by proteolytic degradation caused by salivary enzymes. To overcome this barrier, we used solid phase peptide synthesis (SPPS) to modify the Hst5 amino acid sequence improving its antifungal action and minimizing its degradation. We synthesized five peptides, three of which were based on the Hst5 functional domain. We determined that the smallest peptides (8WH5, 7WH5 and 6WH5) demonstrated the greatest antifungal action against C. albicans, including one fluconazole-resistant strain. Besides that, cationic-PAGE and HPLC assays showed that the degradation in saliva was slower for the smaller peptides than for 0WHst5 and WP113. Furthermore, 8WH5, 7WH5 and 6WH5 were found in the samples even after 8 h in whole saliva, while 0WHst5 and WP113 completely disappear after 1.5 h. Finally, we found that the smaller peptides were less fragmented than the 0WHst5 and WP113, so they were the smallest fragments of Hst5 to preserve its antifungal action with reduced degradation in whole saliva. Thus, they can be considered promising molecules for the treatment of C. albicans in the oral cavity.

Natural and induced immune responses in oral cavity and saliva

This review comprehensively explores the intricate immune responses within the oral cavity, emphasizing the pivotal role of saliva in maintaining both oral and systemic health. Saliva, a complex biofluid, functions as a dynamic barrier against pathogens, housing diverse cellular components including epithelial cells, neutrophils, monocytes, dendritic cells, and lymphocytes, which collectively contribute to robust innate and adaptive immune responses. It acts as a physical and immunological barrier, providing the first line of defense against pathogens. The multifaceted protective mechanisms of salivary proteins, cytokines, and immunoglobulins, particularly secretory IgA (SIgA), are elucidated. We explore the natural and induced immune responses in saliva, focusing on its cellular and molecular composition. In addition to saliva, we highlight the significance of a serum-like fluid, the gingival crevicular fluid (GCF), in periodontal health and disease, and its potential as a diagnostic tool. Additionally, the review delves into the impact of diseases such as periodontitis, oral cancer, type 2 diabetes, and lupus on salivary immune responses, highlighting the potential of saliva as a non-invasive diagnostic tool for both oral and systemic conditions. We describe how oral tissue and the biofluid responds to diseases, including considerations to periodontal tissue health and in disease periodontitis. By examining the interplay between oral and systemic health through the oral-systemic axis, this review underscores the significance of salivary immune mechanisms in overall well-being and disease pathogenesis, emphasizing the importance of salivary mechanisms across the body.

Periodontal Status and Herpesiviridae, Bacteria, and Fungi in Gingivitis and Periodontitis of Systemically Compromised Pediatric Subjects: A Systematic Review

BACKGROUND

Gingivitis and periodontitis are microbially associated diseases, with some features characteristic of pediatric age and others linked to systemic diseases. While the role of periodontal pathogenic bacteria is well recognized, the contribution of fungi and viruses, particularly Herpesviridae, remains controversial. Studies in adults have highlighted the presence of Herpesviridae, but evidence in pediatric subjects, especially systemically compromised, is limited. This systematic review aimed to assess periodontal status (e.g., health, gingivitis, periodontitis, necrotizing gingivitis, and/or periodontitis) and the subgingival and/or salivary microbial (bacterial, viral, and fungal) profile in systemically compromised pediatric (≤18 years) subjects with gingivitis and/or periodontitis compared to clinical periodontal health.

METHODS

The review protocol was registered on PROSPERO (CRD42024597695) and followed the PRISMA statement. Data from eight studies were descriptively analyzed and qualitatively assessed through ROBINS-I and JBI tools.

RESULTS

CMV was frequently detected, particularly in necrotizing gingivitis (19.40%). EBV was found in necrotizing gingivitis (20.69%) and periodontitis (10.34%); HSV was mainly associated with gingivitis and necrotizing gingivitis. Bacteria species in periodontitis included Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium, and Campylobacter species. Candida albicans was detected in periodontitis, suggesting a fungal involvement in the disease's pathogenesis. Although the bacterial and fungal profile was not investigated, limited viral presence was noted in subjects with healthy periodontium, indicating a stable microbiome.

CONCLUSIONS

These findings underscore the dynamics of microbial interactions in the progression of periodontal disease in systemically compromised pediatric subjects.

Antifungal peptides from living organisms

In the post-COVID-19 era, people are increasingly concerned about microbial infections, including fungal infections that have risen in recent years. However, the currently available antifungal agents are rather limited. Worse still, the widespread use of the antifungal agents has caused the emergence of antifungal resistance in Candida, Cryptococcus, and Aspergillus species. Therefore, the development of novel antifungals is urgently needed. Antimicrobial peptides (AMPs), as components of the first-line defense of the host, are found to exhibit broad antimicrobial activity against bacteria, fungi, parasites, viruses, and protozoa. AMPs with antifungal activity are specifically referred to as antifungal peptides (AFPs). AFPs are currently regarded as the most promising alternative to conventional antifungal agents due to the fact that they are highly selective and less prone to facilitate the selection of drug resistance. In this review, we present an overview of the origin and classification of natural AFPs as well as their modes of action. Additionally, the production of natural, semisynthetic, and synthetic AFPs with a view to greater levels of exploitation is discussed. Finally, we evaluate the current and potential applications of AFPs in clinics and in the food industry.

Periodontal health in a large cohort of Ugandans living with HIV: a cross-sectional study

BACKGROUND

The impact of periodontitis on large populations of people living with HIV (PLHIV) in resource-constrained settings remains largely un-investigated. This study aims to address this knowledge gap by providing a comprehensive description of the periodontal health status among a sizable cohort of Ugandans living with HIV.

METHODS

This was a cross-sectional study with 4,449 participants who were over 18-years old with data captured on their reported age, gender, tobacco use, length of time on HAART and alcohol use. Periodontal health was assessed using the WHO periodontal probe and the modified CPI data entry form. Descriptive statistics were reported using frequencies for the affected number of sextants in the surveyed participants. This was followed by additional regression analysis using the R statistical computing environment, with the periodontal health outcomes (bleeding on probing, pocket depth and clinical attachment loss) individually as the dependent, recorded as binary outcomes. A multilevel model was run with clinical attachment loss as the dependant variable controlling for all the other factors. The 95% confidence intervals were used to report the level of significance for each test.

RESULTS

There were 3,103/4,449 (69.7%) female participants. The mean age was 44.3 years (SD 10.1 years) with a range of 18 to 89 years. About 66% of the participants had bleeding on probing at one or more of the examined sites/tooth surfaces. The odds for bleeding on probing were significantly higher for female participants (adjusted Odds ratio: 1.49, 95% CI 1.19 to 1.86), and higher in individuals who reported tobacco use (adjusted odds ratio 1.62, 95% CI 1.09 to 2.41). Slightly under half of our participants (48.2%) had moderate to severe clinical attachment loss.

CONCLUSIONS

This study found that among Ugandans living with HIV, periodontal disease is a significant public health concern. The majority of study participants had bleeding on probing and almost half of them recording moderate to severe clinical attachment loss, worsened by age and time on HAART. This highlights the need for comprehensive oral health care and targeted interventions for this population.

Oral microbiota signatures associated with viremia and CD4 recovery in treatment-naïve HIV-1-infected patients

PURPOSE

Few reports focused on the role of oral microbiome diversity in HIV infection. We characterized the microbiota-immunity axis in a cohort of treatment-naïve HIV-1-infected patients undergoing antiretroviral therapy (ART) focusing on the oral microbiome (OM) and immunological responsivity.

METHODS

The sequencing of 16S rRNA V3-V4 hypervariable region was performed on salivary samples of 15 healthy control (HC) and 12 HIV + patients before starting ART and after reaching virological suppression. Then, we correlated the OM composition with serum cytokines and the Short Chain Fatty acids (SCFAs).

RESULTS

The comparison between HIV patients and HC oral microbiota showed differences in the bacterial α-diversity and richness. We documented a negative correlation between oral Prevotella and intestinal valeric acid at before starting ART and a positive correlation between oral Veillonella and gut acetic acid after reaching virological suppression. Finally, an increase in the phylum Proteobacteria was observed comparing saliva samples of immunological responders (IRs) patients against immunological non-responders (INRs).

CONCLUSIONS

For the first time, we described an increase in the oral pro-inflammatory Proteobacteria phylum in INRs compared to IRs. We provided more evidence that saliva could be a non-invasive and less expensive approach for research involving the oral cavity microbiome in HIV patients.

Periodontal health in a large cohort of Ugandansliving with HIV: A cross-sectional study

Background

The impact of periodontitis on large populations of people living with HIV (PLHIV) in resource-constrained settings remains largely un-investigated. This study aims to address this knowledge gap by providing a comprehensive description of the periodontal health status among a sizable cohort of Ugandans living with HIV.

Methods

This was a cross-sectional study with 4,449 participants who were over 18-years old and captured their reported age, gender, tobacco use, length of time on HAART and alcohol use. Periodontal health was assessed using the WHO periodontal probe and the modified CPI data entry form. Descriptive statistics were reported using frequencies for the affected number of sextants in the surveyed participants. This was followed by additional regression analysis using the R statistical computing environment, with the periodontal health outcomes (bleeding on probing, pocket depth and clinical attachment loss) individually as the dependant, recoded as binary outcomes. A multilevel model was run with clinical attachment loss as the dependant variable controlling for all the other factors. The 95% confidence intervals were used to report the level of significance for each test.

Results

There were 3,103/4,449 (69.7%) female participants. The mean age was 44.3 years (SD 10.1 years) with a range of 18 to 89 years. About 66% of the participants had bleeding on probing at one or more of the examined sites/tooth surfaces. The odds for bleeding on probing were significantly higher for female participants (adjusted Odds ratio: 1.49, 95% CI 1.19 to 1.86), and higher in individuals who reported tobacco use (adjusted odds ratio 1.62, 95% CI 1.09 to 2.41). Slightly under half of our participants (48.2%) had moderate to severe clinical attachment loss.

Conclusions

This study found that among Ugandans living with HIV, periodontal disease is a significant public health concern. The majority (66%) had bleeding on probing, with a sizeable number (48.2%) of participants recording moderate to severe clinical attachment loss, worsened by age and time on HAART. This highlight the need for comprehensive oral health care and targeted interventions for this population.

Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

Immune indices and oral health in patients infected with the human immunodeficiency virus

BACKGROUND

The human immunodeficiency virus (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS). During the incubation period of AIDS, oral manifestations may precede systemic symptoms; therefore, it is vitally important to explore the relationship between HIV and oral health and other indicators. This study aimed to further assess the correlation between demographic risk factors, the dental health of HIV-infected patients, and the correlation of oral health indicators with CD4+ T-cell counts (CTCCs) and HIV viral loads (HIV-VLs).

METHODS

Demographic data on 108 HIV-infected patients were first recorded by questionnaire from March 2016 to November 2018. Patients' dental health and oral lesions were assessed by a dental specialist; in addition, they were tested for CTCCs and HIV-VLs by flow cytometry and NucliSENS EasyQ® HIV-1 virometer. Finally, the links between CTCC, HIV-VL, and the dental health (including oral lesions) of the patients were analyzed.

RESULTS

We found that age, marital status, and body mass index (BMI) were relevant to the patient's dental health (P < 0.05) and that their oral hygiene was relevant to their dental health (P < 0.05). However, HIV-VL was not directly related to periodontal/dental clinical indicators (P > 0.05). We discovered that the oral lesions in HIV-infected patients were related to decreased CTCCs and increased HIV-VLs (P < 0.05).

CONCLUSIONS

We concluded that HIV-infected patients with severely impaired immune function tend to have poor dental health. Moreover, the prevalence of oral lesions was negatively correlated with CTCC and positively correlated with HIV-VL.

Oral health outcomes in an HIV cohort with comorbidities- implementation roadmap for a longitudinal prospective observational study

BACKGROUND

Long-term antiretroviral therapy (ART) perpetually suppresses HIV load and has dramatically altered the prognosis of HIV infection, such that HIV is now regarded as a chronic disease. Side effects of ART in Patients With HIV (PWH), has introduced new challenges including "metabolic" (systemic) and oral complications. Furthermore, inflammation persists despite great viral load suppression and normal levels of CD4+ cell count. The impact of ART on the spectrum of oral diseases among PWH is often overlooked relative to other systemic complications. There is paucity of data on oral complications associated with ART use in PWH. This is in part due to limited prospective longitudinal studies designed to better understand the range of oral abnormalities observed in PWH on ART.

METHODS

We describe here the study design, including processes associated with subject recruitment and retention, study visit planning, oral health assessments, bio-specimen collection and preprocessing procedures, and data management and statistical plan.

DISCUSSION

We present a procedural roadmap that could be modelled to assess the extent and progression of oral diseases associated with ART in PWH. We also highlight the rigors and challenges associated with our ongoing participant recruitment and retention. A rigorous prospective longitudinal study requires proper planning and execution. A great benefit is that large data sets are collected and biospecimen repository can be used to answer more questions in future studies including genetic, microbiome and metabolome-based studies.

TRIAL REGISTRATION

National Institute of Health Clinical Trials Registration (NCT) #: NCT04645693.

Oral Health Outcomes In An HIV Cohort With Comorbidities- Implementation Roadmap For A Longitudinal Prospective Observational Study

Long-term antiretroviral therapy (ART) perpetually suppresses HIV load and has dramatically altered the prognosis of HIV infection, such that HIV is now regarded as a chronic disease. Side effects of ART in Patients With HIV (PWH), has introduced new challenges including "metabolic" (systemic) and oral complications. Furthermore, inflammation persists despite great viral load suppression and normal levels of CD4+ cell count. The impact of ART on the spectrum of oral diseases among PWH is often overlooked relative to other systemic complications. There is paucity of data on oral complications associated with ART use in PWH. This is in part due to limited prospective longitudinal studies designed to better understand the range of oral abnormalities observed in PWH on ART. Our group designed and implemented a prospective observational longitudinal study to address this gap. We present a procedural roadmap that could be modelled to assess the extent and progression of oral diseases associated with ART in PWH. We described here the processes associated with subject recruitment and retention, study visit planning, oral health assessments, bio-specimen collection and preprocessing procedures, and data management. We also highlighted the rigors and challenges associated with participant recruitment and retention.

Independent Effects of HIV and Antiretroviral Therapy on the Oral Microbiome Identified by Multivariate Analyses

The oral microbiome is an important predictor of health and disease. We recently reported significant yet modest effects of HIV under highly active antiretroviral therapy (ART) on the oral microbiome (bacterial and fungal) in a large cohort of HIV-positive (HIV+) and matched HIV-negative (HIV-) individuals. As it was unclear whether ART added to or masked further effects of HIV on the oral microbiome, the present study aimed to analyze the effects of HIV and ART independently, which also included HIV- subjects on preexposure prophylaxis (PrEP) therapy. Cross-sectional analyses of the effect of HIV devoid of ART (HIV+ ART- versus matched HIV- subjects) showed a significant effect on both the bacteriome and mycobiome (P < 0.024) after controlling for other clinical variables (permutational multivariate analysis of variance [PERMANOVA] of Bray-Curtis dissimilarity). Cross-sectional analyses evaluating the effects of ART (HIV+ ART+ versus HIV+ ART- subjects) revealed a significant effect on the mycobiome (P < 0.007) but not the bacteriome. In parallel longitudinal analyses, ART (before versus after the initiation of ART) had a significant effect on the bacteriome, but not the mycobiome, of HIV+ and HIV- PrEP subjects (P < 0.005 and P < 0.016, respectively). These analyses also revealed significant differences in the oral microbiome and several clinical variables between HIV- PrEP subjects (pre-PrEP) and the HIV-matched HIV- group (P < 0.001). At the species level, a small number of differences in both bacterial and fungal taxa were identified within the effects of HIV and/or ART. We conclude that the effects of HIV and ART on the oral microbiome are similar to those of the clinical variables but collectively are modest overall. IMPORTANCE The oral microbiome can be an important predictor of health and disease. For persons living with HIV (PLWH), HIV and highly active antiretroviral therapy (ART) may have a significant influence on their oral microbiome. We previously reported a significant effect of HIV with ART on both the bacteriome and mycobiome. It was unclear whether ART added to or masked further effects of HIV on the oral microbiome. Hence, it was important to evaluate the effects of HIV and ART independently. For this, multivariate cross-sectional and longitudinal oral microbiome analyses (bacteriome and mycobiome) were conducted within the cohort, including HIV+ ART+ subjects and HIV+ and HIV- (preexposure prophylaxis [PrEP]) subjects before and after the initiation of ART. While we report independent significant effects of HIV and ART on the oral microbiome, we conclude that their influence is similar to that of the clinical variables but collectively modest overall.

Immune markers and microbial factors are related with periodontitis severity in people with HIV

OBJECTIVE

The objective of the study is to assess systemic immune markers and microbial factors related to periodontitis severity in people living with HIV.

METHODS

Eighty people living with HIV (PLWH), who exhibited in the last two viral load measurements < 40 copies/mL, underwent full-mouth periodontal examinations and sub-gingival plaque sampling. Periodontitis was classified according to the CDC-AAP case definition. Inflammation, immune-activation, and immunosenescence markers were assessed, microbiological analyses were performed, and oral care routines and HIV characteristics were noted.

RESULTS

From our group of PLWH, 42.5% and 57.5% suffered from moderate and severe periodontitis, respectively. Oral care habits did not differ between PLWH with moderate and severe periodontitis. Bacterial subgingival plaque loads were higher, and Porphyromonas gingivalis was more prevalent in PLWH with severe periodontitis than with moderate periodontitis (53% vs 7%, respectively). Mean C-reactive protein levels [CRP, 1.6 mg/L versus 0.8 mg/L, p = 0.020] and percentages of senescent CD28-CD57 + CD8 + T-cells in peripheral blood [16.5 versus 8.9, p = 0.035] were higher with severe periodontitis. Infection duration, CD4 count, CD4/CD8 ratio and type of antiretroviral therapy did not differ between both groups.

CONCLUSIONS

Periodontitis severity is related to increased prevalence of Porphyromonas gingivalis, elevated CRP levels, and higher frequencies of circulating CD8 + senescent cells in PLWH.

Advances in the oral microbiota and rapid detection of oral infectious diseases

Several studies have shown that the dysregulation of the oral microbiota plays a crucial role in human health conditions, such as dental caries, periodontal disease, oral cancer, other oral infectious diseases, cardiovascular diseases, diabetes, bacteremia, and low birth weight. The use of traditional detection methods in conjunction with rapidly advancing molecular techniques in the diagnosis of harmful oral microorganisms has expanded our understanding of the diversity, location, and function of the microbiota associated with health and disease. This review aimed to highlight the latest knowledge in this field, including microbial colonization; the most modern detection methods; and interactions in disease progression. The next decade may achieve the rapid diagnosis and precise treatment of harmful oral microorganisms.

Factors Associated with Periodontitis in Patients with and without HIV

Purpose

The aim of this study was to compare clinical periodontal conditions in HIV-positive people on HAART with an HIV-negative group, in addition to investigating factors associated with periodontitis in the entire sample.

Methods

This was a cross-sectional study. Data were collected by oral clinical examination for the diagnosis of periodontitis, review of medical records, and application of a questionnaire containing personal data, deleterious habits, and oral hygiene habits for the other variables. The results were analyzed by Pearson's χ ² test and Student's t-test. A logistic regression model was constructed for the multivariate analysis and periodontitis was defined as a dependent variable. The analysis was performed on the entire sample (HIV+ and HIV-) and also on the group consisting of only people living with HIV.

Results

Individuals older than 43 years old and with HIV were more likely to develop moderate and severe periodontitis (47.80 and 4.84 times, respectively). When analyzing only HIV+, in addition to age (OR = 2.795; CI = 1.080-7.233), the use of nonnucleoside reverse transcriptase inhibitors (NNRTIs) (OR = 2.841; CI = 1.135-7.112) was also associated with moderate and severe periodontitis.

Conclusion

It was possible to observe a higher prevalence of periodontitis among individuals with HIV, showing an association between the virus, advanced age, and moderate or severe periodontitis.

Relevant mechanisms of MAIT cells involved in the pathogenesis of periodontitis

Mucosal-associated invariant T (MAIT) cells are a group of unconventional T cells that are abundant in the human body, recognize microbial-derived vitamin B metabolites presented by MHC class I-related protein 1 (MR1), and rapidly produce proinflammatory cytokines, which are widely involved in the immune response to various infectious diseases. In the oral mucosa, MAIT cells tend to accumulate near the mucosal basal lamina and are more inclined to secrete IL-17 when activated. Periodontitis is a group of diseases that manifests mainly as inflammation of the gums and resorption of the alveolar bone due to periodontal tissue invasion by plaque bacteria on the dental surface. The course of periodontitis is often accompanied by a T-cell-mediated immune response. This paper discussed the pathogenesis of periodontitis and the potential contribution of MAIT cells to periodontitis.

Effect of Non-Surgical Periodontal Therapy on Clinical Parameters of Periodontitis, Oral Candida spp. Count and Lactoferrin and Histatin Expression in Saliva and Gingival Crevicular Fluid of HIV-Infected Patients

BACKGROUND

Periodontitis (PDT) has gained attention in the literature with the increase in life expectancy of people living with HIV on combined antiretroviral therapy (cART). Thus, the search for inflammatory biomarkers could be useful to understand the pathophysiology of chronic oral diseases in the cART era.

OBJECTIVE

The aim of this study was to evaluate the impact of non-surgical periodontal therapy (NSPT) on clinical parameters of PDT, Candida spp. count and expression of lactoferrin (LF) and histatin (HST) in saliva and gingival crevicular fluid (GCF) of HIV-infected patients.

METHODS

Bleeding index (BI), probing depth (PD), clinical attachment level (CAL), colonyforming units (CFUs) of Candida spp, and LF and HST levels were measured in saliva and GCF of both groups at three different times: baseline (before treatment), and 30 and 90 days after the NSPT. Clinical, mycological and immunoenzymatic analyses were also performed.

RESULTS

Twenty-two HIV-infected patients and 25 non-HIV-infected patients with PDT participated in the study. NSPT was effective in improving periodontal clinical parameters, including ≤ 4 sites with PD ≤ 5mm and BI ≤ 10%. Significant change in oral Candida spp. count occurred neither between the two groups nor after NSPT. And the salivary and GCF levels of LF and HST were not influenced by the NSPT; by contrast, except for salivary LF, HST and LF were shown to exhibit significantly higher levels in HIV-infected than in non-HIV-infected patients.

CONCLUSION

NSPT was effective in improving periodontal disease parameters in HIV-infected patients, but did not affect LF and HST expression in saliva and GCF of HIV-infected patients.

HIV Infection and Oral Manifestations: An Update

Human immunodeficiency virus (HIV) causes a complete depletion of the immune system; it has been a major health issue around the world since the 1980s, and due to the reduction of CD4+ T lymphocytes levels, it can trigger various opportunistic infections. Oral lesions are usually accurate indicators of immunosuppression because these oral manifestations may occur as a result of the compromised immune system caused by HIV infection; therefore, oral lesions might be initial and common clinical features in people living with HIV. So, it is necessary to evaluate and understand the mechanism, prevalence, and risk factors of oral lesions to avoid the increase morbidity among those with oral diseases.

Oral Manifestations Associated with HIV/AIDS Patients

Oral manifestations are early and important clinical indicators of Human Immunodeficiency Virus (HIV) infection since they can occur in up to 50% of HIV-infected patients and in up to 80% of patients at the AIDS stage (<200 CD4+ T lymphocytes). Oral health is related to physical and mental well-being because the presence of some lesions can compromise dental aesthetics, and alter speech, chewing, and swallowing, thus impacting the quality of life of patients. For this reason, it is necessary to integrate, as part of the medical treatment of HIV-positive patients, the prevention, diagnosis, and control of oral health. It is essential that health professionals have the power to identify, diagnose, and treat oral pathologies through clinical characteristics, etiological agents, and risk factors, both local and systemic. A diagnosis at an early stage of injury allows optimizing and prioritizing oral treatments, especially in acute pathologies, such as gingivitis and necrotizing periodontitis. In this group of patients, the development of strategies for the prevention, control, and reduction of these pathologies must be prioritized in order to reduce morbidity and mortality in this group of patients.

The Expression of miR-34a in Gingival Crevicular Fluid of Chronic Periodontitis and Its Connection with the TLR/NF-κB Signaling Pathway

Objective

This study analyzed the expression of miR-34a in gingival crevicular fluid (GCF) of patients with chronic periodontitis and its connection with the Toll-like receptor (TLR)/nuclear factor kappa-B (NF-κB) signaling pathway.

Methods

We collected the GCF of the two groups of subjects, using RT-PCR to detect the expression of miR-34a and NF-κB p65 mRNA and TLR4 mRNA and ELISA to detect the inflammatory factor degree in GCF, and performed periodontal examinations on both groups.

Results

The gingival index, bleeding index, probe depth, and attachment loss indexes of periodontal examination in the observation group were remarkably superior to those in the control group (P < 0.05). The levels of IL-1β, IL-6, and TNF-α in the GCF of the observation group were higher than those of the control group (P < 0.05). The mRNA relative expression levels of miR-34a, NF-κB p65, and TLR4 in the GCF of the observation group were dramatically higher than those of the control group (P < 0.05). Correlation analysis showed that miR-34a was highly expressed in patients with chronic periodontitis.

Conclusion

There is an abnormally high expression of miR-34a in GCF of chronic periodontitis. Its expression is associated with the degree of periodontal inflammation, periodontal tissue damage, and the activation of the TLR/NF-κB signaling pathway and could be used as a potential index for auxiliary diagnosis and severity of the disease.

In vitro Azole antifungals susceptibility of Candida spp. isolates from HIV-infected patients with periodontitis

OBJECTIVE

The objective of the present study was to determine the in vitro Azole antifungals susceptibility of Candida spp. strains isolated from HIV-positive patients with periodontitis.

METHODS

Oral examination was performed in 500 HIV-positive patients, of which 228 were included in the study for having periodontitis which and separated in two groups based on their TCD4+ T-cells: (A) n = 110 (≤200 CD4+); (B) n = 118 (>200 CD4+). Candida spp. were isolated from the subgingival biofilm and crevicular fluid by seeding on CHROMagar plates and confirmed by endpoint PCR and MALDI-TOF. The susceptibility test in vitro for five antifungals was performed using the disc diffusion method.

RESULTS

From the 228 HIV-positive patients with periodontitis, 174 were positive to Candida spp., and 204 isolations were obtained. 138 (67.64%) were C. albicans, and 66 (32.35%) were Candida non-albicans species. The most frequent Candida non-albicans species in order of frequency were C. glabrata with 48 (23.52%), C. tropicalis with 10 (4.9%), C. krusei with 7 (3.43%), and C. dubliniensis with 1 (0.49%). All species presented resistance to any antifungal: 149 to 5-fluorocytosine (73.0%), 149 to fluconazole (73.0%), and 144 to voriconazole (70.7%). Miconazole and econazole presented the highest susceptibility rates with 129 (63.2%) and 130 (63.7%) isolations, respectively.

CONCLUSION

The Candida spp. involved in periodontitis of HIV-positive patients have a multi-resistant feature. It is necessary to implement recurrent research regarding the antifungal resistance of the Candida spp. that take part in periodontitis pathogenesis to promote an effective treatment in HIV patients.

Oral Cells-On-Chip: Design, Modeling and Experimental Results

Recent advances in periodontal studies have attracted the attention of researchers to the relation between oral cells and gum diseases, which is a real threat to overall human health. Among various microfabrication technologies, Complementary Metal Oxide Semiconductors (CMOSs) enable the development of low-cost integrated sensors and circuits for rapid and accurate assessment of living cells that can be employed for the early detection and control of periodontal diseases. This paper presents a CMOS capacitive sensing platform that can be considered as an alternative for the analysis of salivatory cells such as oral neutrophils. This platform consists of two sensing electrodes connected to a read-out capacitive circuitry designed and fabricated on the same chip using Austria Mikro Systeme (AMS) 0.35 µm CMOS process. A graphical user interface (GUI) was also developed to interact with the capacitive read-out system and the computer to monitor the capacitance changes due to the presence of saliva cells on top of the chip. Thanks to the wide input dynamic range (IDR) of more than 400 femto farad (fF) and high resolution of 416 atto farad (aF), the experimental and simulation results demonstrate the functionality and applicability of the proposed sensor for monitoring cells in a small volume of 1 µL saliva samples. As per these results, the hydrophilic adhesion of oral cells on the chip varies the capacitance of interdigitated electrodes (IDEs). These capacitance changes then give an assessment of the oral cells existing in the sample. In this paper, the simulation and experimental results set a new stage for emerging sensing platforms for testing oral samples.

Management of Periodontal Disease with Adjunctive Therapy with Ozone and Photobiomodulation (PBM): A Randomized Clinical Trial

Periodontitis is an inflammatory condition of the soft and hard tooth-supporting tissues, representing the first cause of tooth loss. In addition to standard mechanical debridement (Scaling and Root Planing, SRP), further approaches have been proposed as adjuncts. The aim of the present randomized clinical trial is to compare the efficacy of ozone or photobiomodulation (PBM) therapy in addition to SRP to treat periodontal disease. According to a split-mouth design, 240 pathological sites, corresponding to 30 periodontal patients, were randomly divided according to the professional oral hygiene protocol performed at baseline (T0) and after 1 (T1), 2 (T2), 3 (T3), 4 (T4), 5 (T5), and 6 (T6) months. A total of 120 sites underwent an ozonized water administration (ozone group), whereas the other 120 sites were treated with photobiomodulation (PBM group), both in addition to SRP. At every timepoint, the following clinical indexes were assessed: Probing Pocket Depth (PPD) (measured on six sites per element), Plaque Index (PI), and Bleeding on Probing (BOP). As regards PPD, significant intergroup differences were noticed from T5, with significantly lower values in the PBM group (p < 0.05), where values further decreased at T6 (p < 0.05). Both PI and BoP generally decreased from baseline to T6 in both groups; a significant difference was found between T0 and T1 among the groups (p < 0.05), with a progressively higher reduction in the PBM group among the time frames of the study, despite intergroup comparisons not being significant (p > 0.05). Both ozone and PBM appear to be effective adjuvant treatments to SRP, obtaining a slightly better outcome for the latter in the long term, with significant differences at T5 and T6 for PPD. However, because of the absence of standardized protocols for PBM considering both therapeutic and research purposes, no definitive conclusions can be reached, and further studies are required.

Cannabinoid control of gingival immune activation in chronically SIV-infected rhesus macaques involves modulation of the indoleamine-2,3-dioxygenase-1 pathway and salivary microbiome

BACKGROUND

HIV/SIV-associated periodontal disease (gingivitis/periodontitis) (PD) represents a major comorbidity affecting people living with HIV (PLWH) on combination anti-retroviral therapy (cART). PD is characterized by chronic inflammation and dysbiosis. Nevertheless, the molecular mechanisms and use of feasible therapeutic strategies to reduce/reverse inflammation and dysbiosis remain understudied and unaddressed.

METHODS

Employing a systems biology approach, we report molecular, metabolome and microbiome changes underlying PD and its modulation by phytocannabinoids [delta-9-tetrahydrocannabinol (Δ9-THC)] in uninfected and SIV-infected rhesus macaques (RMs) untreated (VEH-untreated/SIV) or treated with vehicle (VEH/SIV) or Δ9-THC (THC/SIV).

FINDINGS

VEH- untreated/SIV but not THC/SIV RMs showed significant enrichment of genes linked to anti-viral defense, interferon-β, NFκB, RIG-1, and JAK-STAT signaling. We focused on the anti-microbial DUOX1 and immune activation marker IDO1 that were reciprocally regulated in the gingiva of VEH-untreated/SIV RMs. Both proteins localized to the gingival epithelium and CD163+ macrophages, and showed differential expression in the gingiva of THC/SIV and VEH/SIV RMs. Additionally, inflammation-associated miR-21, miR-142-3p, miR-223, and miR-125a-5p showed significantly higher expression in the gingiva of VEH/SIV RMs. In human primary gingival epithelial cells, miR-125a-5p post-transcriptionally downregulated DUOX1 and THC inhibited IDO1 protein expression through a cannabinoid receptor-2 mediated mechanism. Interestingly, THC/SIV RMs showed relatively reduced plasma levels of kynurenine, kynurenate, and the neurotoxic quinolinate compared to VEH/SIV RMs at 5 months post SIV infection (MPI). Most importantly, THC blocked HIV/SIV-induced depletion of Firmicutes and Bacteroidetes, and reduced Gammaproteobacteria abundance in saliva. Reduced IDO1 protein expression was associated with significantly (p<0.05) higher abundance of Prevotella, Lactobacillus (L. salivarius, L. buchneri, L. fermentum, L. paracasei, L. rhamnosus, L. johnsonii) and Bifidobacteria and reduced abundance of the pathogenic Porphyromonas cangingivalis and Porphyromonas macacae at 5MPI.

INTERPRETATION

The data provides deeper insights into the molecular mechanisms underlying HIV/SIV-induced PD and more importantly, the anti-inflammatory and anti-dysbiotic properties of THC in the oral cavity. Overall, these translational findings suggest that phytocannabinoids may help reduce gingival/systemic inflammation, salivary dysbiosis and potentially metabolic disease/syndrome in PLWH on cART and those with no access to cART or do not suppress the virus under cART.

FUNDING

Research reported in this publication was supported by the National Institutes of Health Award Numbers R01DA052845 (MM and SNB), R01DA050169 (MM and CO), R01DA042524 and R56DE026930 (MM), and P51OD011104 and P51OD011133. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Envisaging Antifungal Potential of Histatin 5: A Physiological Salivary Peptide

Fungi are reported to cause a range of superficial to invasive human infections. These often result in high morbidity and at times mortality. Conventional antifungal agents though effective invariably exhibit drug interactions, treatment-related toxicity, and fail to elicit significant effect, thus indicating a need to look for suitable alternatives. Fungi thrive in humid, nutrient-enriched areas. Such an environment is well-supported by the oral cavity. Despite this, there is a relatively low incidence of severe oral and periodontal fungal infections, attributed to the presence of antimicrobial peptides hosted by saliva, viz. histatin 5 (Hstn 5). It displays fungicidal activity against a variety of fungi including Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and unicellular yeast-like Saccharomyces cerevisiae. Candida albicans alone accounts for about 70% of all global fungal infections including periodontal disease. This review intends to discuss the scope of Hstn 5 as a novel recourse for the control of fungal infections.

Alterations in the oral microbiome in HIV infection: causes, effects and potential interventions

ABSTRACT

A massive depletion of CD4+ T lymphocytes has been described in early and acute human immunodeficiency virus (HIV) infection, leading to an imbalance between the human microbiome and immune responses. In recent years, a growing interest in the alterations in gut microbiota in HIV infection has led to many studies; however, only few studies have been conducted to explore the importance of oral microbiome in HIV-infected individuals. Evidence has indicated the dysbiosis of oral microbiota in people living with HIV (PLWH). Potential mechanisms might be related to the immunodeficiency in the oral cavity of HIV-infected individuals, including changes in secretory components such as reduced levels of enzymes and proteins in saliva and altered cellular components involved in the reduction and dysfunction of innate and adaptive immune cells. As a result, disrupted oral immunity in HIV-infected individuals leads to an imbalance between the oral microbiome and local immune responses, which may contribute to the development of HIV-related diseases and HIV-associated non-acquired immunodeficiency syndrome comorbidities. Although the introduction of antiretroviral therapy (ART) has led to a significant decrease in occurrence of the opportunistic oral infections in HIV-infected individuals, the dysbiosis in oral microbiome persists. Furthermore, several studies with the aim to investigate the ability of probiotics to regulate the dysbiosis of oral microbiota in HIV-infected individuals are ongoing. However, the effects of ART and probiotics on oral microbiome in HIV-infected individuals remain unclear. In this article, we review the composition of the oral microbiome in healthy and HIV-infected individuals and the possible effect of oral microbiome on HIV-associated oral diseases. We also discuss how ART and probiotics influence the oral microbiome in HIV infection. We believe that a deeper understanding of composition and function of the oral microbiome is critical for the development of effective preventive and therapeutic strategies for HIV infection.

Stage II and stage III periodontitis clinical burdens of HIV-1 undergoing antiretroviral therapy

Objectives

The aim of this retrospective cross-sectional study was to estimate the association of HIV-1 infection under highly active antiretroviral treatment (HAART) on the clinical parameters of periodontitis.

Materials and methods

A total of 205 patients were divided in two groups: 74 HIV + and 131 HIV − . Periodontal probing depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), and visible supragingival biofilm (VSB) were recorded. The association of HIV-1 infection with the presence of at least 3 sites with PPD ≥ 5 mm and/or CAL ≥ 4 mm in non-adjacent teeth was estimated using binary logistic regression models.

Results

The variables HIV-1 infection (OR = 5.53, p < 0.0001, 95% CI: 2.45–13.64), age [range 35–50 years old (OR = 5.73, p < 0.0001, 95% CI: 2.49–13.20); > 50 years old (OR = 6.29, p = 0.002, 95% CI: 1.94–20.42)], and VSB (OR = 23.68, p < 0.0001, 95% CI: 8.07–69.53) showed a significant direct association with BOP outcome.

Conclusions

HIV-1 infection under HAART did not have association with the presence of at least 3 sites with PPD ≥ 5 mm and/or CAL ≥ 4 mm. However, HIV patients on HAART had direct association of HIV-1 infection with BOP and an inverse association with PPD.

Clinical relevance

These results support that monitoring gingival bleeding associated with oral prophylaxis would be beneficial in the prevention and management of periodontitis in HIV-1 patients on HAART.

Effect of HIV/HAART and Other Clinical Variables on the Oral Mycobiome Using Multivariate Analyses

The oral microbiome is likely a key element of homeostasis in the oral cavity. With >600 bacterial species and >160 fungal species comprising the oral microbiome, influences on its composition can have an impact on both local and systemic health.

The oral microbiome is considered an important factor in health and disease. We recently reported significant effects of HIV and several other clinical variables on the oral bacterial communities in a large cohort of HIV-positive and -negative individuals. The purpose of the present study was to similarly analyze the oral mycobiome in the same cohort. To identify fungi, the internal transcribed spacer 2 (ITS2) of the fungal rRNA genes was sequenced using oral rinse samples from 149 HIV-positive and 88 HIV-negative subjects that had previously undergone bacterial amplicon sequencing. Quantitative PCR was performed for total fungal content and total bacterial content. Interestingly, samples often showed predominance of a single fungal species with four major clusters predominated by Candida albicans, Candida dubliniensis, Malassezia restricta, or Saccharomyces cerevisiae. Quantitative PCR analysis showed the Candida-dominated sample clusters had significantly higher total fungal abundance than the Malassezia or Saccharomyces species. Of the 25 clinical variables evaluated for potential influences on the oral mycobiome, significant effects were associated with caries status, geographical site of sampling, sex, HIV under highly active antiretroviral therapy (HAART), and missing teeth, in rank order of statistical significance. Investigating specific interactions between fungi and bacteria in the samples often showed Candida species positively correlated with Firmicutes or Actinobacteria and negatively correlated with Fusobacteria, Proteobacteria, and Bacteroidetes. Our data suggest that the oral mycobiome, while diverse, is often dominated by a limited number of species per individual; is affected by several clinical variables, including HIV positivity and HAART; and shows genera-specific associations with bacterial groups.

Long Term Delta-9-tetrahydrocannabinol Administration Inhibits Proinflammatory Responses in Minor Salivary Glands of Chronically Simian Immunodeficieny Virus Infected Rhesus Macaques

HIV/SIV-associated oral mucosal disease/dysfunction (HAOMD) (gingivitis/periodontitis/salivary adenitis) represents a major comorbidity affecting HIV patients on anti-retroviral therapy. Using a systems biology approach, we investigated molecular changes (mRNA/microRNA) underlying HAOMD and its modulation by phytocannabinoids (delta-9-tetrahydrocannabinol (∆⁹-THC)) in uninfected (n = 5) and SIV-infected rhesus macaques untreated (VEH-untreated/SIV; n = 7) or treated with vehicle (VEH/SIV; n = 3) or ∆⁹-THC (THC/SIV; n = 3). Relative to controls, fewer mRNAs were upregulated in THC/SIV compared to VEH-untreated/SIV macaques. Gene enrichment analysis showed differential enrichment of biological functions involved in anti-viral defense, Type-I interferon, Toll-like receptor, RIG-1 and IL1R signaling in VEH-untreated/SIV macaques. We focused on the anti-ER-stress anterior gradient-2 (AGR2), epithelial barrier protecting and anti-dysbiotic WAP Four-Disulfide Core Domain-2 (WFDC2) and glucocorticoid-induced anti-inflammatory TSC22D3 (TSC22-domain family member-3) that were significantly downregulated in oropharyngeal mucosa (OPM) of VEH-untreated/SIV macaques. All three proteins localized to minor salivary gland acini and secretory ducts and showed enhanced and reduced expression in OPM of THC/SIV and VEH/SIV macaques, respectively. Additionally, inflammation associated miR-21, miR-142-3p and miR-29b showed significantly higher expression in OPM of VEH-untreated/SIV macaques. TSC22D3 was validated as a target of miR-29b. These preliminary translational findings suggest that phytocannabinoids may safely and effectively reduce oral inflammatory responses in HIV/SIV and other (autoimmune) diseases.

Quantification of pathogenic bacteria in the subgingival oral biofilm samples collected from cigarette-smokers, individuals using electronic nicotine delivery systems and non-smokers with and without periodontitis

OBJECTIVE

The aim of the present study was to quantify pathogenic bacteria isolated from the subgingival oral-biofilm samples collected from cigarette-smokers and ENDS-users with periodontitis, when compared to non-smokers with and without periodontitis.

METHODS

Demographic data was collected using a questionnaire. Periodontal parameters (plaque [PI] and gingival [GI] indices, clinical attachment loss [CAL], probing depth [PD] and marginal bone loss [MBL]) were measured. Subgingival oral bio-film samples were collected and assessed for periodontopathogenic bacteria (Aggregatibacter actinomycetemcomitans [A. actinomycetemcomitans], Prevotella intermedia [P. intermedia], Porphyromonas gingivalis [P. gingivalis], Tannerella forsythia [T. forsythia] and Treponema denticola [T. denticola]). Group-comparisons were performed; and P < 0.01 were considered statistically significant.

RESULTS

All cigarette-smokers, ENDS-users and non-smokers with periodontitis had Grade-B periodontitis. The CFU/mL of A. actinomycetemcomitans (P < 0.001) and P. gingivalis (P < 0.001) were significantly higher among cigarette-smokers (P < 0.01) and ENDS-users (P < 0.01) than non-smokers with periodontitis. The CFU/mL of T. denticola were significantly higher among cigarette-smokers (P < 0.001), ENDS-users (P < 0.001) and non-smokers with periodontitis (P < 0.001) compared with non-smokers without periodontitis. There was no statistically significant difference in the CFU/mL of P. intermedia and T. denticola among cigarette-smokers, ENDS-users and non-smokers with periodontitis.

CONCLUSION

Counts of periodontopathogenic bacteria in the subgingival oral-biofilm are comparable among cigarette-smokers and individuals using ENDS.

Severe periodontitis is more common in HIV- infected patients

OBJECTIVE

To assess periodontitis prevalence and severity in HIV infected patients as compared to controls. Furthermore, to assess whether HIV infection characteristics are associated with periodontitis.

DESIGN

cross-sectional controlled study.

METHODS

We assessed prevalence and severity of periodontitis in 258 HIV-infected patients and 539 historical controls with the Dutch Periodontal Screening Index (DPSI). HIV characteristics were collected from medical charts. Age-related diseases and oral care were assessed with questionnaires.

RESULTS

Severe periodontitis (DPSI 4) was more prevalent in HIV-infected patients than in controls (66% vs. 36%, p = 0.002). HIV-infection, increasing age and male sex were significant risk factors for severe periodontitis. In particular, older male HIV patients have a higher risk of severe periodontitis. Clinical, immunological and virologic characteristics, and antiretroviral therapy were not associated with periodontitis prevalence or severity. HIV-infected patients rate the importance of their oral health as high, although many do not disclose their HIV infection to their dentists.

CONCLUSIONS

Prevalence and severity of periodontitis are higher in HIV-infected patients compared to controls, particularly in older males. Awareness of the increased prevalence of periodontitis associated with HIV-infection among patients and health-care professionals could significantly improve oral health and quality of life of HIV-infected patients.