Acute Phase Proteins and Their Role in Periodontitis: A Review

Potential role of NSAIDs loaded nano-formulations to treat inflammatory diseases

Inflammation is a necessary immunological response that promotes survival and preserves tissue homeostasis, a common characteristic linked to various diseases. However, in some circumstances, the inflammatory response is deleterious and contributes to disease pathogenesis. Anti-inflammatory substances have poor affinity for inflamed tissues, resulting in low concentrations in the target tissue and a higher incidence of severe adverse effects. To address this issue, several potential approaches have been proposed, such as chemical modification of drug molecules and the development of nanocarriers for drug delivery. Since the development of nanotechnology at the beginning of the twenty-first century, researchers have been using the pathophysiological characteristics of inflammation, primarily leaky vasculature, and biomarker overexpression to develop nanomedicines that can deliver therapeutics via passive and active targeting mechanisms to sites of inflammation and produce therapeutic effects. Drug carriers based on nanoparticles can enhance the safety and efficacy of drugs by increasing their capacity, enhancing their solubility, combining several drugs, protecting them from metabolism, and regulating their release. An approach that shows promise in the treatment of various inflammatory diseases is the application of nanomedicines. Nanomedicine involves nanoparticles that have been loaded with a therapeutically active component. Nanomedicines can target inflammation by recognizing molecules highly expressed on endothelial cells or activated macrophage surfaces, enhancing the permeability of vessels, or even by biomimicry. A review of the research findings shows significant potential for the use of nanotechnology to enhance the quality of life for people using NSAIDs for chronic disorders by minimizing drug side effects or the duration of administration. After a brief introduction to inflammation, its various forms- acute and chronic inflammation, and the pathophysiology of inflammation, this review highlights the main innovative nanocarriers utilized for carrying various nonsteroidal anti-inflammatory drugs that have been utilized in treating various inflammatory disorders.

Periodontitis increases the risk of gastrointestinal dysfunction: an update on the plausible pathogenic molecular mechanisms

Periodontitis is an immuno-inflammatory disease of the soft tissues surrounding the teeth. Periodontitis is linked to many communicable and non-communicable diseases such as diabetes, cardiovascular disease, rheumatoid arthritis, and cancers. The oral-systemic link between periodontal disease and systemic diseases is attributed to the spread of inflammation, microbial products and microbes to distant organ systems. Oral bacteria reach the gut via swallowed saliva, whereby they induce gut dysbiosis and gastrointestinal dysfunctions. Some periodontal pathogens like Porphyromonas. gingivalis, Klebsiella, Helicobacter. Pylori, Streptococcus, Veillonella, Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus, Haemophilus, Aggregatibacter actinomycetomcommitans and Streptococcus mutans can withstand the unfavorable acidic, survive in the gut and result in gut dysbiosis. Gut dysbiosis increases gut inflammation, and induce dysplastic changes that lead to gut dysfunction. Various studies have linked oral bacteria, and oral-gut axis to various GIT disorders like inflammatory bowel disease, liver diseases, hepatocellular and pancreatic ductal carcinoma, ulcerative colitis, and Crohn's disease. Although the correlation between periodontitis and GIT disorders is well established, the intricate molecular mechanisms by which oral microflora induce these changes have not been discussed extensively. This review comprehensively discusses the intricate and unique molecular and immunological mechanisms by which periodontal pathogens can induce gut dysbiosis and dysfunction.

Changes and Roles of IL-6, hsCRP, and proCT in Patients with Chronic Periodontitis in Head and Neck Cancer Pre/Post Radiotherapy

Background: Head and neck cancer (HNC) patients frequently undergo radiotherapy as a standalone treatment or in combination with chemotherapy. Radiotherapy is associated with adverse effects, including detrimental impacts on periodontal health, which increase the risk of periodontitis. Objective: To investigate the clinical significance of interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP), and procalcitonin (proCT) as prognostic indicators. Methods: 150 participants were divided into three groups: (n=50, HNC post-RT) patients with head and neck cancer who had radiation treatment six months ago (n=50, HNC pre-RT), and individuals with periodontal health as the control group (n=50). Probing pocket depth (PPD), clinical attachment loss (CAL), gingival bleeding index (GBI), plaque index (PI), and hyposalivation were meticulously recorded. To quantify serum concentrations of IL-6, hs-CRP, and proCT, an electrochemiluminescence immunoassay (eCLIA) was used. Results: Serum levels of IL-6, hsCRP, and proCT were significantly elevated in two groups of patients with chronic periodontitis with head and neck cancer post-radiotherapy (CP+HNC post-RT) and patients with chronic periodontitis with HNC pre-radiotherapy (CP+HNC pre-RT) compared to a control group. ROC analysis demonstrated the diagnostic accuracy of IL-6, hsCRP, and proCT for both clinical cases. Furthermore, all clinical periodontal index scores (CAL, PPD, PI, and GBI) were significantly elevated compared to a control group. Conclusions: HNC post-RT patients presented significantly higher serum IL-6, hs-CRP, proCT, and periodontal score levels than HNC pre-RT.

More than just teeth: How oral health can affect the heart

Epidemiological evidence has revealed a potential relationship between periodontal disease and cardiovascular disease (CVD). Consensus regarding a link between these pathologies remains elusive, however, largely secondary to the considerable overlap between risk factors and comorbidities common to both disease processes. This review article aims to update the evidence for an association by summarizing the evidence for causality between periodontitis and comorbidities linked to CVD, including endocarditis, hypertension (HTN), atrial fibrillation (AF), coronary artery disease (CAD), diabetes mellitus (DM) and hyperlipidemia (HLD). This article additionally discusses the role for periodontal therapy to improved management of the comorbidities, with the larger goal of examining the value of periodontal therapy on reduction of CVD risk. In doing so, we endeavor to further the understanding of the commonality between periodontitis, and CVD.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

Mechanism and application of Lactobacillus in type 2 diabetes-associated periodontitis

Type 2 diabetes mellitus (T2DM) accelerates the progression of periodontitis through diverse pathways. Abnormal immune responses, excessive activation of inflammation, increased levels of advanced glycation end products, and oxidative stress have defined roles in the pathophysiological process of T2DM-associated periodontitis. Furthermore, in the periodontium of diabetic individuals, there are high levels of advanced glycation end-products and glucose. Meanwhile, progress in microbiomics has revealed that dysbacteriosis caused by T2DM also contributes to the progression of periodontitis. Lactobacillus, owing to its fine-tuning function in the local microbiota, has sparked tremendous interest in this field. Accumulating research on Lactobacillus has detailed its beneficial role in both diabetes and oral diseases. In this study, we summarize the newly discovered mechanisms underlying Lactobacillus-mediated improvement of T2DM-associated periodontitis and propose the application of Lactobacillus in the clinic.

Efficacy of curcumin gel as an adjunct to scaling and root planing on salivary procalcitonin level in the treatment of patients with chronic periodontitis: a randomized controlled clinical trial

THE AIM OF THE STUDY

To evaluate the effect of curcumin gel combined with scaling and root planing (SRP) on salivary procalcitonin in periodontitis treatment.

MATERIALS AND METHODS

seventy patients were selected from the Department of Oral Medicine and Periodontology, Faculty of Dentistry, Mansoura University, and sixteen patients were excluded. Patients in groups II and III included stage II grade A periodontitis. The participants were classified into three groups: group I as a negative control group (individuals with healthy gingiva), group II (SRP) were treated with SRP, and group III (curcumin gel) which was applied weekly for four weeks after SRP. Clinical indices (plaque index (PI), gingival index (GI), clinical attachment level (CAL), and probing depth (PD)) and saliva samples for procalcitonin (PCT) assessment using an enzyme-linked immunosorbent assay (ELISA) test were collected and measured at both baselines and after six weeks.

RESULTS

This randomized controlled clinical trial registered on ClinicalTrials.gov (NCT05667376) and first posted at 28/12/2022 included Fifty-four patients (20 male; 34 female). Regarding the age and sex distribution, there was no statistically significant difference between the three studied groups (p > 0.05). There was no significant statistical difference regarding PI, GI, PPD, and CAL between group II and group III at baseline p (> 0.05). However, there was a significant statistical difference regarding the clinical parameters at baseline of both group II and group III as compared to group I (p ≤ 0.05). At six weeks after treatment, group III showed greater improvement in the PI, PD, and CAL as opposed to group II (p ≤ 0.05). Regarding PCT values, at baseline, there wasn't a statistically significant difference between group II and group III (p > 0.05). However, there was a significant statistical difference between group II, group III, and group I (p ≤ 0.05). At six weeks after treatment, there was a statistically significant decrease in PCT levels of both group II and III (p ≤ 0.05).

CONCLUSION

The application of curcumin gel was found to have a significant effect on all clinical indices as opposed to SRP.

Association between the severity of periodontitis, COVID-19, C-reactive protein and interleukin-6 levels in hospitalized patients: a case‒control study

BACKGROUND

The COVID-19 pandemic is perhaps one of the most important events of the 21st century. Periodontitis is one of the most prevalent diseases of the oral cavity. Due to possible pathways of interaction between these two diseases, we investigated their association.

METHODS

The study population consisted of hospitalized patients with established COVID-19 diagnoses. Patients with mild to moderate COVID-19 were considered controls, while cases had severe to critical COVID-19. Periodontal examination and serum and saliva sampling were performed for each patient. Relevant medical data were extracted from patients' hospital files.

RESULTS

Of the enrolled patients, 122 were included in the statistical analyses. The severity of periodontitis was directly and significantly correlated with the severity of COVID-19 (P < 0.001). Patients with generalized stage III or IV periodontitis displayed an adjusted odds ratio of 4.24 for severe to critical COVID-19. Salivary and serum interleukin-6 levels were significantly associated with COVID-19 severity (P values: 0.002 and 0.004, respectively). Hospitalization length was significantly associated with the severity of periodontitis (P = 0.004). Clinical attachment level and gingival index were associated with increased odds for adverse events (P values: 0.004 and 0.035, respectively), while number of remaining teeth was associated with decreased odds for adverse events (P = 0.023).

CONCLUSIONS

This study showed that the severity of periodontitis is associated with the severity of COVID-19. This association might manifest as increased odds of adverse events. COVID-19 severity was associated with higher levels of salivary and serum interleukin-6 levels.

Comparison of interleukin expression in gingival crevicular fluid between patients with invisible orthodontics treat-ment and fixed orthodontics treatment

OBJECTIVES

To compare the expression levels of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-16, and IL-18 in gingival crevicular fluid between patients with invisible orthodontics treatment and fixed orthodontics treatment.

METHODS

A total of 67 patients with invisible orthodontic treatment were selected as the observation group, and 40 patients with fixed orthodontic treatment were selected as the control group. The expression levels of IL-1β, IL-6, IL-8, IL-10, IL-16, and IL-18 in gingival crevicular fluid before, 24 h, and 12 months after orthodontic treatment were detected.

RESULTS

No significant difference in basic characteristics and interleukin expression levels in gingival crevicular fluid was observed between the two groups before orthodontic treatment (P>0.05). After 24 h of orthodontic treatment, the expression levels of IL-1β, IL-6, IL-8, IL-10, and IL-18 in gingival crevicular fluid increased in both groups; however, no significant difference was observed between the two groups (P>0.05). After 12 months of orthodontic treatment, the expression levels of IL-1β, IL-6, IL-8, IL-10, and IL-18 in gingival crevicular fluid in the observation group were significantly lower than those in the control group (P<0.05), and no significant difference in the expression level of IL-16 was observed between the two groups (P>0.05).

CONCLUSIONS

Compared with patients with fixed orthodontics treatment, those with invisible orthodontics treatment had weaker oral inflammatory response, which was conducive to the recovery of the oral microenvironment.

Inflammation: A New Look at an Old Problem

Pro-inflammatory stress is inherent in any cells that are subject to damage or threat of damage. It is defined by a number of universal components, including oxidative stress, cellular response to DNA damage, unfolded protein response to mitochondrial and endoplasmic reticulum stress, changes in autophagy, inflammasome formation, non-coding RNA response, formation of an inducible network of signaling pathways, and epigenetic changes. The presence of an inducible receptor and secretory phenotype in many cells is the cause of tissue pro-inflammatory stress. The key phenomenon determining the occurrence of a classical inflammatory focus is the microvascular inflammatory response (exudation, leukocyte migration to the alteration zone). This same reaction at the systemic level leads to the development of life-critical systemic inflammation. From this standpoint, we can characterize the common mechanisms of pathologies that differ in their clinical appearance. The division of inflammation into alternative variants has deep evolutionary roots. Evolutionary aspects of inflammation are also described in the review. The aim of the review is to provide theoretical arguments for the need for an up-to-date theory of the relationship between key human pathological processes based on the integrative role of the molecular mechanisms of cellular and tissue pro-inflammatory stress.

Type 1 Diabetic Patients After Simultaneous Pancreas and Kidney Transplantation Have Less Intense Periodontal Inflammation Compared to Kidney Recipients Treated with Insulin

BACKGROUND Long-term diabetes predisposes to pathological changes in periodontal tissues. Improvement in this respect can be expected in patients after pancreas transplantation. The aim of this study was to assess and compare the intensity of periodontium pathological lesions and inflammation markers concentration in gingival crevicular fluid (GCF) in patients with type 1 diabetes (T1D) after kidney (KTx) or simultaneous pancreas and kidney transplantation (SPK). MATERIAL AND METHODS The study included 20 T1D patients after SPK and 16 after KTx, and 15 non-diabetic kidney recipients (control). Periodontal clinical parameters and concentration of selected biochemical markers of inflammation in GCF were assessed. The following tests were used in statistical data analysis: Shapiro-Wilk test, the t test, the Mann-Whitney U tests, one-way ANOVA with Tukey's post hoc test, and χ² test (also with Yate's correction). Moreover, linear regression and Pearson or Spearman correlation coefficient was used. RESULTS There were no differences in modified Sulcus Bleeding Index (mSBI) and GCF volume between the SPK group and control group, whereas values of these parameters in the KTx group were higher than in the SPK and control groups. Maximal clinical attachment loss and pocket depth and Periotest values were higher in diabetic recipients compared to controls, and did not differ between SPK and KTx. The concentration of IL-1ß, MMP-8, resistin, TNFalpha, and YKL40 in the GCF in the KTx group was higher than in the SPK and control groups. In the combined group of T1D patients, there was a correlation between blood HbA1c and mSBI, GCF volume, and resistin, TNF-alpha and YKL40 concentrations, and between resistin concentration and mSBI. CONCLUSIONS T1D patients after SPK show lower levels of inflammatory markers in GCF and present reduced intensity of periodontitis compared to kidney recipients treated with insulin. The severity of morphological changes in periodontium in T1D patients after KTx or SPK is higher than in non-diabetic kidney recipients.

Estimation and correlation of procalcitonin in saliva and serum of chronic periodontitis patients before and after nonsurgical periodontal therapy: An analytical comparative study

Background

Procalcitonin (ProCT) is an emerging inflammatory biomarker in bacterial infections. Few studies have reported raising salivary ProCT in periodontitis patients. Hence, the study aims to analyze and correlate the changes in saliva and serum ProCT in periodontitis patients before and after nonsurgical periodontal therapy.

Materials and Methods

We have included 15 chronic periodontitis patients of mean age 41.8 ± 6.82 years who satisfy the inclusion criteria in the study. After saliva and serum collection, clinical parameters such as plaque index, gingival index, gingival bleeding index, probing pocket depth, and clinical attachment were recorded, and scaling and root debridement were performed. Reevaluation was done at 1- and 3-month interval. ProCT was estimated using the enzyme-linked immunosorbent assay.

Results

Salivary ProCT was significantly greater than its serum counterpart at baseline and 1 month after periodontal therapy (0.20 vs. 0.26, 0.13 vs. 0.14 ng/ml respectively). We noticed a significant reduction in salivary as well as serum ProCT (35% and 46%, respectively) 1 month after scaling and root debridement. A significant moderate positive correlation was found between paired observations of salivary and serum ProCT at baseline as well as after periodontal therapy (r = 0.61 and 0.7). A further reduction of salivary ProCT was noticed 3 months after nonsurgical therapy (0.11 ng/ml).

Conclusions

Serum ProCT significantly decreases with periodontal treatment, indicating the impact of periodontal therapy on systemic inflammation. Since salivary ProCT is positively correlated with serum ProCT, we can consider it as an alternative biomarker to its serum counterpart.

Suppressed immune profile in children with combined type 1 diabetes and celiac disease

Children diagnosed with a combination of type 1 diabetes (T1D) and celiac disease (CD) show a dysregulated T helper type 1 (Th1)/Th17 response. Besides the cellular involvement, several soluble immune markers are involved in the autoimmune process of both T1D and CD. Only few studies have examined the peripheral pattern of different cytokines, chemokines and acute-phase proteins (APP) in children with combined T1D and CD. To our knowledge, no studies have evaluated the serum levels of adipocytokines and matrix metalloproteinases (MMPs) in this context. The purpose of the present study was to acquire more knowledge and to gain deeper understanding regarding the peripheral immunoregulatory milieu in children with both T1D and CD. The study included children diagnosed with both T1D and CD (n = 18), children with T1D (n = 27) or CD (n = 16) and reference children (n = 42). Sera were collected and analysis of 28 immune markers (cytokines, chemokines, APPs, adipocytokines and MMPs) was performed using the Luminex technique. The major findings showed that children with a double diagnosis had lower serum levels of interleukin (IL)-22, monocyte chemoattractant protein (MIP)-1α, monocyte chemoattractant protein (MCP)-1, procalcitonin, fibrinogen, visfatin and matrix metalloproteinase (MMP)-2. These results indicate a suppressed immune profile in children with combined T1D and CD, including Th17 cytokines, chemokines, APPs, adipocytokines and MMPs. We conclude that, besides cytokines and chemokines, other immune markers, e.g. APPs, adipocytokines and MMPs, are of importance for further investigations to elucidate the heterogeneous immune processes present in patients diagnosed with T1D in combination with CD.

[Research progress of correlation between periodontal pathogens and systemic diseases]

Periodontal pathogens are the main pathogenic factor of periodontitis. Periodontal pathogens have a large variety of virulence factors such as lipopolysaccharide, fimbriae and proteases, which enables the pathogens to infect periodontal tissues and stimulate the secretion of inflammatory cytokines, causing chronic systemic inflammation. Periodontal pathogens may invade multiple systems such as the circulatory system, immune system, respiratory system and digestive system to cause systematic diseases. Recent studies have shown that periodontal pathogens may have close relations with systemic diseases such as cardiovascular disease, diabetes, rheumatoid arthritis, and cancer. Among the periodontal pathogens, Porphyromonas gingivalis can be found in atherosclerotic plaques to impairing the function of the vascular endothelium; Porphyromonas gingivalis may also increase the level of inflammatory factors such as TNF-α to promote insulin resistance and diabetes. Many of the periodontal pathogens such as Porphyromonas gingivalis, Tannerella forsythia and Prevotella intermedia can be detected in the synovial fluid of rheumatoid arthritis patients, suggesting their involvement in the pathogenesis of rheumatoid arthritis. Fusobacterium nucleatum may cause alterations in the intestinal microbiome in mice and promote the occurrence of intestinal tumors. Herein we review the recent progresses in the relationship between periodontal pathogens and systemic diseases.

[Anemia in the aged]

Anemia in the aged is still often an underestimated clinical problem; however, in recent years increasing research on this topic has permitted deeper insights, allowing a differentiated approach to anemia in the aged. Meanwhile, multicausality and a negative impact on functional outcome have become characteristics of anemia in older people. This has led to a scientific discussion on the question of accepting anemia as a geriatric syndrome. The present article gives a concise overview of the current state of research on this clinically relevant subject.

Association between Periodontal Health Status and Cognitive Abilities. The Role of Cytokine Profile and Systemic Inflammation

Background:

Contemporary neurobiology, periodontal medicine, and immunology are now focusing on the relationship between chronic periodontitis and systemic diseases, which also include Alzheimer’s disease (AD). However a causative relationship between dementia and periodontitis has yet to be confirmed.

Objective:

The aim of the study was to determine whether periodontal health status and cognitive abilities are correlated with the relative changes in systemic measures of pro- and anti-inflammatory cytokines as a reflection of systemic inflammation. We hypothesized that poor periodontal health status may be associated with cognitive impairment and dementia via the exacerbation of systemic inflammation.

Methods:

Based on the periodontal and psychiatric examinations and the cytokine levels produced by unstimulated and LPS-stimulated PBL isolated from 128 participants, we have examined if the coexisting of these two clinically described conditions may have influence on the systemic inflammation. Mini-Mental State Examination (MMSE) and Bleeding on Probing (BoP) test results were combined into the one mathematical function U, which determines the severity of specific condition, called Cognitive and periodontal impairment state. Similarly, the levels of cytokines were combined into the one mathematical function V, whose value determines the level of Inflammatory state. The correlation between U and V was determined.

Results:

These results confirm that the presence of cognitive decline and the additional source of pro-inflammatory mediators, like periodontal health problems, aggravate the systemic inflammation.

Conclusion:

It is most likely that the comorbidity of these two disorders may deepen the cognitive impairment, and neurodegenerative lesions and advance to dementia and AD.

Effect of scaling and root planing on gingival crevicular fluid level of YKL-40 acute phase protein in chronic periodontitis patients with or without type 2 diabetes mellitus: A clinico-biochemical study

BACKGROUND

The aim of the present study was to evaluate the gingival crevicular fluid (GCF) levels of YKL-40 acute phase protein in chronic periodontitis (CP) with and without type 2 diabetes and also to assess the effect of periodontal therapy (scaling and root planing [SRP]) on this GCF biomarker and the clinical parameters. YKL-40 is derived from tyrosine (Y), lysine (K), and leucine (L) with a molecular weight of 40 kDa.

MATERIALS AND METHODS

A total of 105 individuals (30-60 years) were grouped as 35 individuals each in three groups (Group I - healthy; Group II - CP with diabetes mellitus [DM]; and Group III - CP). Clinical parameters including plaque index, gingival index, probing pocket depth, and clinical attachment level followed by GCF sample collection from test sites were done at baseline and 6 weeks after SRP (among Group II and Group III patients). GCF YKL-40 level was determined by enzyme-linked immunosorbent assay.

RESULTS

The mean GCF YKL-40 level at baseline was significantly lower for Group I (309.81 ± 124.93 pg/ml) as compared to Group II (924.88 ± 415.28 pg/ml) and Group III (834.08 ± 270.42 pg/ml), respectively (P < 0.001). The level reduced significantly 6 weeks after SRP for Group II (507.6 ± 265.03 pg/ml) and Group III (499.54 ± 293.38 pg/ml) (P < 0.001).

CONCLUSION

The level of GCF YKL-40 in CP patients with or without DM is higher than healthy individuals and the level reduced 6 weeks post-SRP among Group II and Group III. Hence, YKL-40 can be considered as an important biomarker in the diagnosis of CP.

Association of circulating leptin and adiponectin with periodontitis: a systematic review and meta-analysis

BACKGROUND

This study aimed to assess the difference in serum levels of leptin and adiponectin in patients with periodontitis and in periodontally healthy individuals and evaluate the changes in circulating leptin and adiponectin after periodontal therapy. Leptin and adiponectin are the most generally studied adipokines that function as inflammatory cytokines. Although the association between periodontitis and serum levels of leptin and adiponectin has been studied extensively, the results were not consistent.

METHODS

A systematic search of the Pubmed, Embase, Web of Science, and Cochrane Library up to September 2016 was conducted. The studies were screened and selected by two writers according to the specific eligibility criteria. The quality of included cross-sectional studies was assessed using the quality assessment form recommended by the Agency for Healthcare Research and Quality and Methodological Index for Nonrandomized Studies. The meta-analyses were conducted using the STATA 12.0 software.

RESULTS

A total of 399 manuscripts were yielded and 25 studies were included in the present meta-analysis. Significantly elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis were observed in the subgroup analysis of body mass index (BMI) <30. The overall and subgroup analyses showed no significant change in the serum levels of leptin in patients with periodontitis after periodontal treatment. The subgroup analysis of systemically healthy patients showed no significant change in serum levels of adiponectin in patients with periodontitis after periodontal treatment.

CONCLUSIONS

The present meta-analysis supported elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis compared with controls in the BMI <30 population. In systemically healthy patients with periodontitis, serum levels of leptin and adiponectin do not significantly change after periodontal treatment.

The Infectious Etiology of Alzheimer's Disease

BACKGROUND

Inflammation is a part of the first line of defense of the body against invasive pathogens, and plays a crucial role in tissue regeneration and repair. A proper inflammatory response ensures the suitable resolution of inflammation and elimination of harmful stimuli, but when the inflammatory reactions are inappropriate it can lead to damage of the surrounding normal cells. The relationship between infections and Alzheimer's Disease (AD) etiology, especially lateonset AD (LOAD) has been continuously debated over the past three decades.

METHODS

This review discusses whether infections could be a causative factor that promotes the progression of AD and summarizes recent investigations associating infectious agents and chronic inflammation with AD. Preventive and therapeutic approaches to AD in the context of an infectious etiology of the disease are also discussed.

RESULTS

Emerging evidence supports the hypothesis of the role of neurotropic viruses from the Herpesviridae family, especially Human herpesvirus 1 (HHV-1), Cytomegalovirus (CMV), and Human herpesvirus 2 (HHV-2), in AD neuropathology. Recent investigations also indicate the association between Hepatitis C virus (HCV) infection and dementia. Among bacteria special attention is focused on spirochetes family and on periodontal pathogens such as Porphyromonas gingivalis or Treponema denticola that could cause chronic periodontitis and possibly contribute to the clinical onset of AD.

CONCLUSION

Chronic viral, bacterial and fungal infections might be causative factors for the inflammatory pathway in AD.

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

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

Effect of non-surgical periodontal treatment on transferrin serum levels in patients with chronic periodontitis

Background. Transferrin is a negative acute phase protein, which decreases during inflammation and infection. The aim of the present investigation was to evaluate changes in the transferrin serum levels subsequent to non-surgical treatment of chronic periodontal disease. Methods. Twenty patients with chronic periodontitis and 20 systemically healthy subjects without periodontal disease, who had referred to Tabriz Faculty of Dentistry, were selected. Transferrin serum levels and clinical periodontal parameters (pocket depth, clinical attachment level, gingival index, bleeding index and plaque index) were measured at baseline and 3 months after non-surgical periodontal treatment. Data were analyzed with descriptive statistical methods (means ± standard deviations). Independent samples t-test was used to compare transferrin serum levels and clinical variables between the test and control groups. Paired samples t-test was used in the test group for comparisons before and after treatment. Statistical significance was set at P < 0.05. Results. The mean transferrin serum level in patients with chronic periodontitis (213.1 ± 9.2 mg/dL) was significantly less than that in periodontally healthy subjects (307.8 ± 11.7 mg/dL). Three months after periodontal treatment, the transferrin serum level increased significantly (298.3 ± 7.6 mg/dL) and approached the levels in periodontally healthy subjects (P < 0.05). Conclusion. The decrease and increase in transferrin serum levels with periodontal disease and periodontal treatment, respectively, indicated an inverse relationship between transferrin serum levels and chronic periodontitis.