Elevated serum interleukin-6 (IL-6) in solid-organ transplant recipients is positively associated with tissue destruction and IL-6 gene expression in the periodontium

Oral health of patients suffering from end-stage solid organ insufficiency prior to solid organ re-transplantation: a retrospective case series study

Background

The oral health of organ transplanted patients before organ re-transplantation is largely unknown. This retrospective clinical study evaluates the necessity for intraoral surgical intervention and/or conservative treatment in candidates awaiting organ re-transplantation, both for graft failure and for reasons of another upcoming solid organ transplantation (renal or non-renal).

Methods

From January 2015 to March 2020 n = 19 transplant recipients in evaluation on the waiting list for solid organ re-transplantation could be included in the retrospective case series study. Using clinical and radiological examinations, necessity for oral surgical or conservative dental treatment was evaluated. On the basis of anamnesis data, current kidney function, renal replacement treatment (RRT), and medication, a risk profile for several patient subgroups was created.

Results

The clinical and radiological examinations showed a conservative and/or surgical treatment need in n = 13 cases (68.42%). In n = 7 cases (36.84%) surgical intervention was recommended due to residual root remnants (n = 5), unclear mucosal changes (n = 1), and periimplantitis (n = 1). In n = 16 recipients (84.2%) RRT (n = 15 hemodialysis; n = 1 peritoneal dialysis) had been performed. N = 14 recipients (73.68%) received immunosuppressants. In n = 1 patient (5.3%) displayed intraoral and n = 4 patients (21.1%) extraoral neoplasms due to drug-induced immunosuppression.

Conclusions

Solid organ transplant recipients with renal failure present a complex treatment profile due to a double burden of uremia plus immunosuppressants. In cases of surgical treatment need a hospitalized setting is recommended, where potentially necessary follow-up care and close cooperation with disciplines of internal medicine is possible in order to avoid surgical and/or internal complications.

Frequency of the necessity of dentoalveolar surgery or conservative treatment in patients before kidney transplantation depending on the duration of dialysis and causative nephrological disease

OBJECTIVES

This retrospective study evaluates intraoral surgical and conservative treatment need in patients with a chronic kidney end-stage disease, depending on the duration of dialysis treatment and the causative nephrological disease.

MATERIAL AND METHODS

This study is based on data of patients referred to the Department of Oral and Maxillofacial Surgery of the University Hospital Erlangen, Germany, prior to kidney transplantation between January 2015 and March 2020. The necessity for oral surgical or dental therapy was determined by clinical and radiological examinations. Data on renal replacement therapy, cause of underlying renal disease, lifestyle, and general health were collected.

RESULTS

Data of N = 89 patients demonstrated that surgical treatment need depends on dialysis duration (p = 0.042). Patients, who had been dialyzing for 2 to 3 years showed the highest need for surgical intervention (80.0%; p = 0.024), followed by dialysis patients with a dialysis time of more than 3 years (48.1%). Similarly, dialysis patients in the second or third year of dialysis had the highest need for conservative treatment (73.3%; p > 0.05), followed by 55.6% of dialysis patients in the third year of dialysis.

CONCLUSIONS

Operative and conservative treatment is essential to optimize subsequent kidney transplantation. The greatest necessity could be detected for patients in the second and third years of dialysis.

CLINICAL RELEVANCE

Oral health addressing surgical and conservative treatment need depends on the duration of dialysis in patients with a chronic kidney end-stage disease.

DNA-PKcs Inhibition Extends Allogeneic Skin Graft Survival

BACKGROUND

Organ transplantation is life-saving and continued investigations into immunologic mechanisms that drive organ rejection are needed to improve immunosuppression therapies and prevent graft failure. DNA-dependent protein kinase catalytic subunit, DNA dependent-protein kinase catalytic subunit (DNA-PKcs), is a critical component of both the cellular and humoral immune responses. In this study, we investigate the contribution of DNA-PKcs to allogeneic skin graft rejection to potentially highlight a novel strategy for inhibiting transplant rejection.

METHODS

Fully MHC mismatched murine allogeneic skin graft studies were performed by transplanting skin from BalbC mice to C57bl6 mice and treating with either vehicle or the DNA-PKcs inhibitor NU7441. Graft rejection, cytokine production, immune cell infiltration, and donor-specific antibody formation were analyzed.

RESULTS

DNA-PKcs inhibition significantly reduced necrosis and extended graft survival compared with controls (mean survival 14 d versus 9 d, respectively). Inhibition reduced the production of the cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ and the infiltration of CD3+ lymphocytes into grafts. Furthermore, DNA-PKcs inhibition reduced the number of CD19+ B cells and CD19+ CD138+ plasma cells coinciding with a significant reduction in donor-specific antibodies. At a molecular level, we determined that the immunosuppressive effects of DNA-PKcs inhibition were mediated, in part, via inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells signaling through reduced expression of the p65 subunit.

CONCLUSIONS

Our data confirm that DNA-PKcs contributes to allogeneic graft rejection and highlight a novel immunologic function for DNA-PKcs in the regulation of nuclear factor kappa-light-chain-enhancer of activated B cells and concomitant cytokine production.

The Effect of Gaseous Ozone Therapy in Conjunction with Periodontal Treatment on Glycated Hemoglobin Level in Subjects with Type 2 Diabetes Mellitus: An Unmasked Randomized Controlled Trial

BACKGROUND

It is established that inflammation is involved in the pathogenesis of Type 2 Diabetes Mellitus (T2DM) by promoting insulin resistance and impaired beta cell function in the pancreas. Among the hypothesized independent risk factors implicated in the pathogenetic basis of disease, periodontal infection has been proposed to promote an amplification of the magnitude of the advanced glycation end product (AGE)-mediated upregulation of cytokine synthesis and secretion. These findings suggest an interrelationship between periodontal disease and type 2 diabetes, describing poor metabolic control in subjects with periodontitis as compared to nondiabetic subjects and more severe periodontitis in subjects with T2DM as compared to a healthy population, with a significant positive correlation between periodontal inflammatory parameters and glycated hemoglobin level. Results from clinical trials show that periodontal treatment is able to improve glycemic control in subjects with diabetes. Many therapeutic strategies have been developed to improve periodontal conditions in conjunction with conventional treatment, among which ozone (O₃) is of specific concern. The principal aim of this trial was to compare the clinical effectiveness of an intensive periodontal intervention consisting of conventional periodontal treatment in conjunction with ozone gas therapy in reducing glycated hemoglobin level in type 2 diabetic patients and standard periodontal treatment.

METHODS

This study was a 12-month unmasked randomized trial and included 100 patients aged 40-74 years older, with type 2 diabetes mellitus diagnosed. All the patients received conventional periodontal treatment, or periodontal treatment in conjunction with ozone gas therapy in a randomly assigned order (1:1). The primary outcome was a clinical measure of glycated hemoglobin level at 3, 6, 9 and 12 months from randomization. Secondary outcomes were changes in periodontal inflammatory parameters.

RESULTS

At 12 months, the periodontal treatment in conjunction with ozone gas therapy did not show significant differences than standard therapy in decreasing glycated hemoglobin (HbA1C) level and the lack of significant differences in balance is evident.

CONCLUSIONS

Although the change was not significant, periodontal treatment in conjunction with the gaseous ozone therapy tended to reduce the levels of glycated hemoglobin. The study shows a benefit with ozone therapy as compared to traditional periodontal treatment.

Periodontitis Impact in Interleukin-6 Serum Levels in Solid Organ Transplanted Patients: A Systematic Review and Meta-Analysis

This systematic review aimed to investigate the influence of periodontitis on post-transplant IL-6 serum levels of solid organ transplanted patients as compared to healthy subjects. Four databases (PubMed, Scholar, EMBASE, and CENTRAL) were searched up to February 2020 (PROSPERO CRD42018107817). Case-control and cohort studies on the association of IL-6 serum levels with a periodontal status of patients after solid organ transplantation were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Random effects meta-analyses were thoroughly conducted. GRADE assessment provided quality evidence. Four case-control studies fulfilled the inclusion criteria (274 transplant recipients and 146 healthy controls), all of low risk of bias. Meta-analyses revealed significantly higher IL-6 levels in transplanted patients than healthy individuals with low-quality evidence (Mean Difference (MD): 2.55 (95% confidence interval (CI): 2.07, 3.03)). Transplanted patients with periodontitis have higher serum IL-6 levels than transplanted patients without periodontitis with moderate quality evidence (MD: 2.20 (95% CI: 1.00, 3.39)). We found low-quality evidence of higher IL-6 levels than healthy patients in patients with heart and kidney transplant. In these transplanted patients, there was moderate quality evidence that periodontitis is associated with higher IL-6 serum levels. Future research should consider the impact of such a difference in organ failure and systemic complications.

Periodontitis: Tip of the iceberg in chronic kidney disease

The prevalence of chronic kidney disease (CKD) is constantly escalating not only in industrialized countries but throughout the world. It is of major significance because of to its high morbidity and mortality. Strategies to tackle this worldwide health problem include identification of its associated risk factors, comorbidities, and complications as well as proper management to handle all the pertinent issues. Periodontal disease, a treatable infectious state of the dental supporting tissues, is common in CKD patients. Its association with CKD is believed to be in a reciprocal or bidirectional fashion and has been massively studied. This paper, therefore, aims to review the recent evidence pertaining to the association between periodontal disease and a variety of renal illnesses. Most of the current evidence was collected from cross-sectional studies and clinical trials. There is substantial evidence indicating that periodontal disease contributes markedly to the chronic systemic inflammatory burden, leading to cardiovascular and cerebrovascular complications, the principal causes of death among chronic renal disease patients. Furthermore, several studies demonstrated that proper periodontal intervention could help improve systemic inflammation and even nutritional status among CKD patients, resulting in a better quality of life. Suggestions have been made that periodontal disease should be diagnosed early, and managed and controlled to, at least, eradicate a source of inflammation in this population. Awareness of such an important issue should be increased in the relevant medical personnel.

Oxantel disrupts polymicrobial biofilm development of periodontal pathogens

Bacterial pathogens commonly associated with chronic periodontitis are the spirochete Treponema denticola and the Gram-negative, proteolytic species Porphyromonas gingivalis and Tannerella forsythia. These species rely on complex anaerobic respiration of amino acids, and the anthelmintic drug oxantel has been shown to inhibit fumarate reductase (Frd) activity in some pathogenic bacteria and inhibit P. gingivalis homotypic biofilm formation. Here, we demonstrate that oxantel inhibited P. gingivalis Frd activity with a 50% inhibitory concentration (IC50) of 2.2 μM and planktonic growth of T. forsythia with a MIC of 295 μM, but it had no effect on the growth of T. denticola. Oxantel treatment caused the downregulation of six P. gingivalis gene products and the upregulation of 22 gene products. All of these genes are part of a regulon controlled by heme availability. There was no large-scale change in the expression of genes encoding metabolic enzymes, indicating that P. gingivalis may be unable to overcome Frd inhibition. Oxantel disrupted the development of polymicrobial biofilms composed of P. gingivalis, T. forsythia, and T. denticola in a concentration-dependent manner. In these biofilms, all three species were inhibited to a similar degree, demonstrating the synergistic nature of biofilm formation by these species and the dependence of T. denticola on the other two species. In a murine alveolar bone loss model of periodontitis oxantel addition to the drinking water of P. gingivalis-infected mice reduced bone loss to the same level as the uninfected control.

Effect of periodontal treatment on glycemic control of patients with diabetes: A systematic review and meta-analysis

AIMS/INTRODUCTION

The aim of the present study was to investigate whether non-surgical periodontal treatment reduces glycated hemoglobin (HbA1c) and fasting plasma glucose (FPG) levels in diabetic patients.

MATERIALS AND METHODS

An electronic search was carried out on MEDLINE (through PubMed interface), EMBASE and the Cochrane Central Register of Controlled Trials. Randomized controlled trials with a minimum of 3 months follow up were included. The risk of bias was assessed for each study. A meta-analysis was carried out to evaluate the effect of non-surgical periodontal treatment on HbA1c and FPG levels. The effect of the adjunctive use of antimicrobials was also assessed.

RESULTS

A total of 15 studies were included. A reduction of -0.38% (95% confidence interval [CI] -0.23 to -0.53) after 3-4 months (P < 0.001) and of -0.31% (95% CI 0.11 to -0.74) after 6 months (P = 0.15) of follow-up was found for HbA1c, favoring the treatment group. Similarly, in treated patients, a significantly greater decrease in FPG was observed in respect to control participants. Such difference amounted to -9.01 mg/dL (95% CI -2.24 to -15.78) after 3-4 months (P = 0.009) and -13.62 mg/dL (95% CI 0.45 to -27.69) after 6 months (P = 0.06) from treatment, respectively. In participants treated with adjunctive antimicrobials, a non-significant increase of HbA1c was observed 3 months after treatment, whereas FPG decreased by 0.27 mg/dL (95% CI 39.56 to -40.11; P = 0.99).

CONCLUSIONS

The meta-analysis showed that non-surgical periodontal treatment improves metabolic control in patients with both periodontitis and diabetes.

Periodontitis predicts elevated C-reactive protein levels in chronic kidney disease

Based on the existing evidence supporting a state of chronic inflammation in chronic kidney disease (CKD), we hypothesized that periodontal infection may affect the systemic inflammatory status of a nationally representative CKD population as measured by serum C-reactive protein (CRP). We examined this hypothesis using the National Health and Nutrition Examination Survey 1988-1994 (NHANES III) dataset including 2303 individuals. We followed the American Academy of Periodontology (AAP)/Centers for Disease Control and Prevention (CDC) case definition for periodontitis. We used a cutoff point of 30% sites with (PD) ≥ 5 mm and (CAL) ≥ 4 mm to define generalized periodontitis cases. We estimated glomerular filtration rate based on cystatin C levels using the relevant equation. Urinary albumin-to-creatinine ratio was calculated in milligrams per gram with a cutoff point of 30 mg/g. CKD was defined based on eGFR < 60 mL/min/1.73 m(2) and albuminuria ≥ 30 mg/g. Periodontitis was found in 427 (12.3%) individuals. Of individuals with periodontitis, 41.8% had serum CRP higher than 0.3 mg/dL compared with 27.1% of non-periodontitis and 53.1% of edentulous individuals (p = 0.001 for all comparisons). When the extent of periodontitis was used as one of the independent variables, the parsimonious model showed a strong independent association between extent of periodontitis and serum CRP levels (OR = 2.0, CI95% = 1.2-3.6).

Dentistry and internal medicine: from the focal infection theory to the periodontal medicine concept

During past decades the relationship between dentistry and internal medicine and especially the concept of the so-called focal infection theory have long been a matter of debate. The pathogenesis of focal diseases has been classically attributed to dental pulp pathologies and periapical infections. Nonetheless, in recent years, their role is being dismissed while increasing interest is being devoted to the possible associations between periodontal infection and systemic diseases. In fact, periodontal pathogens and their products, as well as inflammatory mediators produced in periodontal tissues, might enter the bloodstream, causing systemic effects and/or contributing to systemic diseases. On the basis of this mechanism, chronic periodontitis has been suggested as a risk factor for cardiovascular diseases associated with atherosclerosis, bacterial endocarditis, diabetes mellitus, respiratory disease, preterm delivery, rheumatoid arthritis, and, recently, osteoporosis, pancreatic cancer, metabolic syndrome, renal diseases and neurodegenerative diseases such as Alzheimer's disease. Various hypotheses, including common susceptibility, systemic inflammation, direct bacterial infection and cross-reactivity, or molecular mimicry, between bacterial antigens and self-antigens, have been postulated to explain these relationships. In this scenario, the association of periodontal disease with systemic diseases has set the stage for introducing the concept of periodontal medicine. This narrative review summarizes the evolution of focal infection theory up to the current pathophysiology of periodontal disease, and presents an update on the relationships between chronic periodontitis and systemic diseases.

Inhibition of allogeneic inflammatory responses by the Ribonucleotide Reductase Inhibitors, Didox and Trimidox

Background

Graft-versus-host disease is the single most important obstacle facing successful allogeneic stem cell transplantation (SCT). Even with current immunosuppressive therapies, morbidity and mortality rates are high. Current therapies including cyclosporine A (CyA) and related compounds target IL-2 signaling. However, although these compounds offer great benefit, they are also associated with multiple toxicities. Therefore, new compounds with a greater efficacy and reduced toxicity are needed to enable us to overcome this hurdle.

Methods

The allogeneic mixed lymphocyte reaction (MLR) is a unique ex vivo method to study a drug's action on the initial events resulting in T-cell activation and proliferation, synonymous to the initial stages of tissue and organ destruction by T-cell responses in organ rejection and Graft-versus-host disease. Using this approach, we examined the effectiveness of two ribonucleotide reductase inhibitors (RRI), Didox and Trimidox, to inhibit T-cell activation and proliferation.

Results

The compounds caused a marked reduction in the proliferative responses of T-cells, which is also accompanied by decreased secretion of cytokines IL-6, IFN-γ, TNF-α, IL-2, IL-13, IL-10 and IL-4.

Conclusions

In conclusion, these data provide critical information to justify further investigation into the potential use of these compounds post allogeneic bone marrow transplantation to alleviate graft-versus-host disease thereby achieving better outcomes.

Effect of periodontal treatment on glycemic control of diabetic patients: a systematic review and meta-analysis

OBJECTIVE

There is growing evidence that periodontitis may affect general health. This study was assigned to explore the robustness of observations that periodontal therapy leads to the improvement of glycemic control in diabetic patients.

RESEARCH DESIGN AND METHODS

A literature search (until March 2009) was carried out using two databases (MEDLINE and the Cochrane Library) with language restriction to English. Selection of publications was based on 1) original investigations, 2) controlled periodontal intervention studies where the diabetic control group received no periodontal treatment, and 3) study duration of > or =3 months.

RESULTS

Screening of the initial 639 identified studies and reference checking resulted in five suitable articles. A total of 371 patients were included in this analysis with periodontitis as predictor and the actual absolute change in A1C (DeltaA1C) as the outcome. The duration of follow-up was 3-9 months. All studies described a research population of type 2 diabetic patients in whom glycemic control improved after periodontal therapy compared with the control group (range DeltaA1C: Delta-1.17 up to Delta-0.05%). The studies in a meta-analysis demonstrated a weighted mean difference of DeltaA1C before and after therapy of -0.40% (95% CI -0.77 to -0.04%, P = 0.03) favoring periodontal intervention in type 2 diabetic patients. Nevertheless, this improvement in %A1C must be interpreted with care due to limited robustness as evidenced by heterogeneity among studies (59.5%, P = 0.04).

CONCLUSIONS

The present meta-analysis suggests that periodontal treatment leads to an improvement of glycemic control in type 2 diabetic patients for at least 3 months.

Inflammation in renal transplantation

BACKGROUND AND OBJECTIVES

Renal transplant recipients experience premature cardiovascular disease and death. The association of inflammation, all-cause mortality, and cardiovascular events in renal transplant recipients has not been examined in a large prospective controlled trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

ALERT was a randomized, double-blind, placebo-controlled study of the effect of fluvastatin on cardiovascular and renal outcomes in 2102 renal transplant recipients. Patients initially randomized to fluvastatin or placebo in the 5- to 6-yr trial were offered open-label fluvastatin in a 2-yr extension to the original study. The association between inflammation markers, high-sensitivity C-reactive protein (hsCRP), and IL-6 on cardiovascular events and all-cause mortality was investigated.

RESULTS

The baseline IL-6 value was 2.9 +/- 1.9 pg/ml (n = 1751) and that of hsCRP was 3.8 +/- 6.7 mg/L (n = 1910). After adjustment for baseline values for established risk factors, the hazard ratios for a major cardiac event and all-cause mortality for IL-6 were 1.08 [95% confidence interval (CI), 1.01 to 1.15, P = 0.018] and 1.11 (95% CI, 1.05 to 1.18, P < 0.001), respectively. The adjusted hazard ratio for hsCRP for a cardiovascular event was 1.10 (95% CI, 1.01 to 1.20, P = 0.027) and for all-cause mortality was 1.15 (95% CI, 1.06 to 1.1.25, P = 0.049).

CONCLUSIONS

The inflammation markers IL-6 and hsCRP are independently associated with major cardiovascular events and all-cause mortality in renal transplant recipients.

Cardiovascular disease and periodontitis: an update on the associations and risk

BACKGROUND

Associations between periodontitis and cardiovascular diseases have been recognized.

MATERIAL AND METHODS

New literature since the last European Workshop on Periodontology has been reviewed.

RESULTS

The lack of reliable epidemiological data on disease prevalence makes an assessment of the associations and risks between periodontitis and cardiovascular diseases difficult. Two recent meta-analysis reports have identified associations between periodontitis and cardiovascular diseases (odds ratios: 1.1-2.2). Different surrogate markers for both disease entities, including serum biomarkers, have been investigated. Brachial artery flow-mediated dilatation, and carotid intima media thickness have in some studies been linked to periodontitis. Studies are needed to confirm early results of improvements of such surrogate markers following periodontal therapy. While intensive periodontal therapy may enhance inflammatory responses and impair vascular functions, studies are needed to assess the outcome of periodontal therapies in subjects with confirmed cardiovascular conditions. Tooth eradication may also reduce the systemic inflammatory burden of individuals with severe periodontitis. The role of confounders remain unclear.

CONCLUSIONS

Periodontitis may contribute to cardiovascular disease and stroke in susceptible subjects. Properly powered longitudinal case-control and intervention trials are needed to identify how periodontitis and periodontal interventions may have an impact on cardiovascular diseases.

A systematic review and meta-analyses on C-reactive protein in relation to periodontitis

AIM

Elevated plasma C-reactive protein (CRP) is regarded as a risk predictor for cardiovascular diseases. This systematic review explored the robustness of observations that CRP is elevated in periodontitis. Similarly, the effect of periodontal therapy on CRP levels was investigated.

MATERIAL AND METHODS

Selection of publications was based on: (1) cross-sectional (case-control) studies; (2) longitudinal (treatment) studies; (3) high-sensitivity CRP measurement; (4) median and/or mean (+/-SD) values presented; and (5) subjects with no systemic disorders.

RESULTS

Screening of the initially 448 identified studies and reference checking resulted in 18 suitable papers. The majority of the studies showed that CRP levels are higher in patients than in controls. Often, studies showed that patients had CRP levels >2.1 mg/l. A meta-analysis of 10 cross-sectional studies showed that the weighted mean difference (WMD) of CRP between patients and controls was 1.56 mg/l (p<0.00001). Evidence from available treatment studies (n=6) showed lower levels of CRP after periodontal therapy. Eligible treatment studies in a meta-analysis demonstrated a WMD of reductions of CRP after therapy of 0.50 mg/L (95% CI 0.08-0.93) (p=0.02).

CONCLUSIONS

There is strong evidence from cross-sectional studies that plasma CRP in periodontitis is elevated compared with controls. There is modest evidence on the effect of periodontal therapy in lowering the levels of CRP.