Interleukin 4 haplotypes of susceptibility to chronic periodontitis are associated with IL-4 protein levels but not with clinical outcomes of periodontal therapy

Inflammatory mediators for predicting the risk of trauma‐induced root resorption: A systematic review

BACKGROUND/AIM

External inflammatory root resorption (EIRR) and external replacement root resorption (ERRR) are the most common adverse outcomes after luxation injuries or dental injuries. They are usually detected radiographically after considerable progression. It can be envisaged that evaluation of inflammatory mediators might serve as an objective and reliable method of predicting the risk of resorption. The aim of this systematic review was to assess the evidence regarding the risk of resorption and to provide future research directions.

METHODS

An a priori protocol was prepared by a multidisciplinary expert group, as per the Cochrane handbook and PRISMA guidelines. The systematic search was conducted in six databases and grey-literature sources. Scrutiny of titles and abstracts, and later full-text articles was performed, and data were extracted. Risk of bias analysis was done by using the Joanna Briggs Institute's Critical Appraisal Checklist for analytical cross-sectional and cohort studies.

RESULTS

Eight studies were included in the systematic review and could be categorized as per the source of biomarkers, namely epithelial cells from mucosa, gingival crevicular fluid and extracted teeth. The studies utilizing epithelial cells had been conducted between 2015 and 2018 in Brazil and did not find any correlation with EIRR. Two of the studies with extracted teeth found differences in the immunologic profiles of teeth with resorption. Three studies evaluating gingival crevicular fluid found increased levels of dentine sialoprotein and Interleukin-1-α.

CONCLUSION

Among the three sources, the inflammatory gingival crevicular fluid appeared to be the most non-invasive source of biomarkers for predicting trauma-induced root resorption, although the evidence about this came from two studies with moderate and one study with high risk of bias. The primary studies in this systematic review showed variability in terms of the sample sizes, age of the patients, the grading/classification of trauma-induced resorption and the evaluation methods which must be addressed by future researchers.

Types of External Root Resorption of Replanted Teeth: Analysis of the Clinical Aspects and of Interleukin-4 Gene Polymorphisms Involvement

INTRODUCTION

The absence or presence of root resorption on the surface of a replanted tooth indicates an immune-inflammatory reaction. Recent research even suggests the participation of host predominant immunologic profile on types of resorptions detected on the root surface. Because interleukin 4 (IL-4) is an important anti-inflammatory cytokine, this study aimed to investigate the association of clinical variables and polymorphisms in IL4 with types of resorption of replanted teeth after 1 year of follow-up.

METHODS

One hundred twenty-seven avulsed teeth that were replanted were selected. Periapical radiographs were taken after replantation and for 1 year to detect the types of root resorption. Real-time polymerase chain reaction was used to genotype IL4 polymorphisms. The χ² and Z tests were performed to verify the association of clinical and genetic variables with the outcomes of replanted teeth (P < .05).

RESULTS

An association was observed of extra-alveolar time, storage medium, and development of the root (P < .05), but not of IL4 polymorphisms, with the outcomes of replanted teeth (P > .05).

CONCLUSIONS

Extraoral time, storage medium, and development of the root, but not IL4 polymorphisms, may influence the types of resorption of avulsed and replanted teeth in the first year after trauma.

Clinical response to non-surgical periodontal treatment in patients with interleukin-6 and interleukin-10 polymorphisms

Background

Genetic polymorphisms are commonly associated with altered transcriptional activity and possibly make individuals more susceptible to periodontal disease development, increased disease severity and poor treatment outcome. The study aimed to determine the effect of Interleukin-6 (IL-6) -572 G/C (rs1800796) and IL-10 -592 C/A (rs1800872) polymorphisms on the outcomes of non-surgical periodontal therapy in a Caucasian population.

Material and Methods

Sixty-eight patients with chronic periodontal disease were grouped according to their genotype: IL-6, IL-10, IL-6 and IL-10 susceptible (SCP) and non-susceptible (NSCP). All individuals were clinically evaluated at the first visit, and blood sample were collected from patients after checking the inclusion and exclusion criteria of the study. All patients received non-surgical periodontal therapy from a single-blinded periodontist. Clinical periodontal measurements were repeated 45 days after therapy.

Results

This population mean aged 47.63 years included 52.2% females and 58.2% non-smokers. Following DNA separation and genotyping, 65.7% of patients were homozygous carriers of the IL-6 - 572G; 49.3% were carriers of the IL-10 -592A- allele (AA and CA genotypes); and 35.8% carried SCP genotypes for both polymorphisms. The clinical parameters after therapy were not associated with the genotype status. The multiple logistic regression analysis did not show any statistically significant association between the genotypes and the variables tested.

Conclusions

Within the limitations of this longitudinal study, it can be suggested that IL-6 -572 G/C and IL-10 -592 C/A polymorphisms as well as their combination do not influence the outcome of nonsurgical periodontal therapy in Caucasian patients diagnosed with chronic periodontal disease.

Key words:Gene polymorphism, genetics, interleukins, periodontal disease, treatment outcome.

Analysis of the association of clinical factors and IL4 gene polymorphisms with root resorption in avulsed teeth after 1 year of replantation

AIM

To investigate the association of clinical variables and polymorphisms (tag SNPs) in the interleukin 4 (IL4) gene, with the prognosis of avulsed and replanted teeth.

METHODOLOGY

Ninety-four patients who suffered avulsion and had their teeth replanted and endodontically treated were included. Periapical radiographs were obtained soon after tooth replantation and after 1 year. For genotypic IL4 gene analysis, the DNA from oral mucosa cells was collected, and polymorphisms were investigated by real-time PCR. Univariate and multivariate analyses were performed to verify the association of clinical and genetic variables and the outcome of the replanted teeth (P < 0.05).

RESULTS

After multivariate analysis, extra-alveolar time longer than 1 h was significantly associated with external root resorption. No significant association was observed between IL4 gene polymorphisms and root resorption.

CONCLUSION

No association between root resorption and IL4 gene polymorphisms was observed. An extra-alveolar time of more than 1 h was associated with a susceptibility for external root resorption. Replanting the tooth in its socket immediately is the most important factor to maintain a healthy root surface.

Functional Haplotypes in Interleukin 4 Gene Associated with Periodontitis

Chronic periodontitis (CP) is an infectious inflammatory disease that affects tooth-supporting structures and in which dental plaque bacteria, immune mechanisms and genetic predisposition play important roles. Interleukin 4 (IL-4) is a key anti-inflammatory cytokine with relevant action in imbalances in inflamed periodontal tissue. Individuals carrying the TCI/CCI genotype (S-haplotype) of the IL-4 gene are 5 times more susceptible to CP, whereas the CTI/TTD genotype (P-haplotype) confers protection against CP. Compared with the S-haplotype, subjects with the P-haplotype produce higher levels of the IL-4 protein after non-surgical periodontal therapy. The present in vitro study aimed to investigate the functionality of IL-4 haplotypes in immune cells to obtain insight into the influence of these genetic variations in regulating immune responses to CP-associated bacteria. Peripheral blood was collected from 6 subjects carrying each haplotype, and their immune cells were challenged with periodontopathogens to compare responses of the different haplotypes with regard to gene expression, protein secretion and the immunophenotype of T helper responses. We found higher IL-4 mRNA and protein levels in the P-haplotype, which also presented higher levels of anti-inflammatory cytokines. In contrast, cells from S-haplotype subjects responded with higher levels of pro-inflammatory cytokines. S-haplotype individuals exhibited significantly greater polarization toward the Th1 phenotype, whereas the P-haplotype was associated with an attenuated response to periodontopathogens, with suggestive skewing toward Th2/M2 phenotypes. In conclusion, IL-4 genetic variations associated with susceptibility to or protection against chronic periodontitis are directly associated with influencing the response of immune cells to periodontopathogens.

Gingival crevicular fluid levels of cytokines/chemokines in chronic periodontitis: a meta-analysis

AIMS

To compare gingival crevicular fluid (GCF) cytokines/chemokines levels between periodontally healthy subjects and subjects diagnosed with chronic periodontitis (ChP), before and after non-surgical periodontal treatment, and to establish their predictive value for periodontal disease progression.

METHODS

Studies indexed in MEDLINE and EMBASE published in English, Portuguese and Spanish were eligible for this review. Database searches up to December 2015, and manual search of the reference list from reviews and selected articles was performed. Only studies providing data on GCF cytokines/chemokines levels in subjects diagnosed with ChP and periodontally healthy controls were included. Cross-sectional, case series, single-arm clinical studies, randomized controlled trials and prospective/retrospective cohort studies were included. Meta-analyses were conducted for those cytokines/chemokines with at least three available studies.

RESULTS

GCF levels of IL-1β, IL-6, IFN-γ and MCP-1/CCL2 were significantly higher in subjects diagnosed with ChP than periodontally healthy subjects. A significant decrease in GCF levels of IL-1β and IL-17 was observed after non-surgical periodontal treatment, whereas a significant increase was observed for IL-4.

CONCLUSION

Evidence for significant differences between periodontal health and ChP was observed for a few cytokines and one chemokine. No conclusions could be drawn with regards to increased risk of disease progression.

Association of susceptible genotypes to periodontal disease with the clinical outcome and tooth survival after non-surgical periodontal therapy: A systematic review and meta-analysis

Background

The real clinical utility of genetic testing is the prognostic value of genetic factors in the clinical outcome of periodontal treatment and the tooth survival. A meta-analysis was undertaken to estimate the effect of a susceptible genotype to periodontitis on the clinical outcomes of non-surgical periodontal therapy and the tooth survival.

Material and Methods

A systematic search of MEDLINE-Pubmed, Cochrane Library and Scopus was performed. Additionally, a hand search was done in three journals. No specific language restriction was applied. Two reviewers screened independently titles and abstracts or full text copies. Quality assessment of all the included studies was held.

Results

Initial screening of electronic databases resulted in 283 articles. Ten studies met the inclusion criteria, nine of them examined the clinical outcome, while the other one investigated the tooth survival in susceptible individuals after non-surgical periodontal therapy. Eight of included studies were selected for the meta-analysis. IL-1 positive genotypes increase the risk of tooth loss, while no association found between the bleeding on probing (BOP), clinical attachment loss (CAL) and plaque index (PI) with the genotype status. Probing pocket depth (PPD) reduction in the first three months and in long-term results found to have a significant association with the genotype.

Conclusions

There is no difference in the clinical measurements after non-surgical periodontal treatment, apart from PPD. More publications are needed to identify a cause-effect relationship.

Key words:Periodontal disease, periodontitis, periodontal therapy, clinical outcome, tooth loss, susceptibility, polymorphism, genotype, meta-analysis, systematic review.