Association study of interleukin-1 family and interleukin-6 gene single nucleotide polymorphisms in recurrent aphthous stomatitis

Assessing the thyroid autoimmunity association with recurrent aphthous stomatitis

BACKGROUND

Recent investigations have highlighted autoimmune origins and abnormal immune responses; particularly those related to T cell-mediated immunity and elevated T lymphocyte cells in the oral mucosa. Therefore, we investigated the relationship between recurrent aphthous stomatitis (RAS) and autoimmune thyroid diseases (ATDs) in an Iranian population.

METHODS

A cross-sectional study was performed on 102 patients diagnosed with ATD (cases) and 102 healthy patients (controls) who had been referred for the routine dental treatment. All participants were asked for the history of RAS and their age, gender, other systemic diseases, medications, and frequency of RAS in a year. Matching was performed based on the propensity scores for age and sex. In addition, the number of lesions in each recurrence in both groups was assessed and compared. The type of thyroid disease has been assessed for case participants and has been confirmed by the endocrinologist. The chi-square test, t-test, and Mann-Whitney U test were used to analyze the data using SPSS 18.

RESULTS

Patients with ATD had higher RAS than healthy controls (P = 0.040). ATD patients had 1.93 times more risk for RAS, and the frequency of RAS in a year was 3.15times higher in these patients (P = 0.011). Moreover, the frequency of RAS was higher in patients with hypothyroidism than in those with hyperthyroidism. However, there were no significant differences in the size and the number of lesions between the groups.

CONCLUSION

The risk and frequency of RAS were significantly higher in patients with ATDs. This would provide valuable insights into the underlying mechanisms and potential treatment strategies for both conditions.

Association of Surfactant Protein D Single Nucleotide Polymorphisms rs721917, rs2243639, rs3088308 with Recurrent Aphthous Stomatitis in Pakistani Population

Recurrent aphthous stomatitis (RAS) is a benign ulcerative condition, defined by the recurrent formation of non-contagious mucosal ulcers. Surfactant protein D (SP-D) is secreted frequently at surfaces exposed directly to body fluids. This study aims to investigate the association of SP-D single nucleotide polymorphisms (SNPs) with the onset of RAS. Blood samples from 212 subjects (106 cases/controls each) were collected during 2019 and genotyped for SP-D SNPs (rs721917, rs2243639, rs3088308) by polymerase chain reaction and restriction fragment length polymorphism followed by 12% polyacrylamide gel electrophoresis. Minor aphthous (75.5%) was the commonly observed ulcer type as compared to herpetiform (21.7%) and major aphthous ulcers (2.8%). A family history of RAS was reported in 70% of cases. RAS was found significantly associated with rs3088308 genotypes T/A (95% (Cl): 1.57-5.03, p = 0.0005), A/A (95% (Cl): 1.8-6.7, p = 0.0002), T-allele (95% (Cl): 1.09-2.36, p = 0.01), A-allele (95% (Cl): 1.42-3.91, p = 0.01), rs721917 genotype T/T (95% (Cl): 1.15-25.35, p = 0.03), and T-allele (95% (Cl): 1.28-3.10, p = 0.002). Female gender and obese body mass index (BMI) were significantly associated with rs3088308 genotypes T/A (95% (CI): 1.89-15.7, p = 0.001), T/T (95% (Cl): 1.52-11.9, p = 0.005), A-allele (95% (Cl): 1.65-7.58, p < 0.001), and T-allele (95% (Cl): 1.4-10.1, p <0.001) and rs721917 genotype T/T (95% (CI) = 1.3-33, p = 0.02), respectively. This study describes the association of SP-D SNPs (rs721917, rs3088308) with RAS in the Pakistani population.

The expression of TNF-α in recurrent aphthous stomatitis: A systematic review and meta-analysis

OBJECTIVE

The pathogenesis of recurrent aphthous stomatitis (RAS) is related to an increase of pro-inflammatory cytokine, namely tumor necrosis factor α (TNF-α). This cytokine plays an important role in the development of ulcer lesions, both in saliva, tissues and blood. This systematic review analyzed the differences of TNF-α in lesions, salivary and blood and can be used as a reliable method of diagnosis for RAS.

METHODS

A comprehensive search of PubMed, Scopus databases, Web of Science, Scielo, Google Scholar and Embase with keywords. The inclusion criteria were studies that assessed the saliva, serum, and RAS lesion, with the outcome reporting the mean of saliva, serum and tissue expression of TNF-α. The risk of bias was also assessed.

RESULT

Healthy individuals showed significantly lower TNF-α than RAS (SMD = -1.517, 95% CI [-2.25, -0.78]). Although there is a significant difference between sample (i.e., saliva, serum) and detection type (i.e., cytometry bead array, ELISA), both methods can detect a significant difference in TNF-α between healthy individuals and RAS patients.

CONCLUSIONS

The TNF-α is a useful diagnostic marker for RAS. We encourage saliva to detect changes in TNF-α during ulceration as it provides accuracy, reliability, and non-invasive procedure compared to a blood draw.

Risk of cancer in patients with recurrent aphthous stomatitis in Korea: A nationwide population-based study

The relationship between recurrent aphthous stomatitis (RAS), a common mucosal lesion, and cancer has not been demonstrated. This study investigated the risk for developing cancer in patients with RAS, based on data from Korea's National Health Insurance Sharing Service (NHISS). Nationwide population-based cohort data from 2005 to 2009 provided by the NHISS was used. The group diagnosed with RAS for 5 years and an undiagnosed control group were constructed through 1:1 propensity score matching (PSM). The experimental design compared the incidence rate of a cancer diagnosis from 2010 to 2015 between these 2 groups. After identifying 13,808 people that met our inclusion criterion from a 1 million cohort group, 13,808 controls were included in the study through PSM. Among all cancers, pancreatic cancer had an adjusted hazard ratio of 1.26 (95% confidence interval: 1.01-1.57, P < .041). For the rest of the cancers, there was no significant incidence rate. RAS was associated with an increased risk of pancreatic cancer in the analysis using large population-based cohort data. Further long-term follow-up studies are needed.

The Impact of DNA Methylation on IL6 mRNA Levels in Hematinic Deficiency and Atopy-Associated Recurrent Aphthous Stomatitis Patients

Objective

To investigate the DNA methylation using pyrosequencing and its effects on the upregulation of IL6 mRNA in patients with recurrent aphthous stomatitis (RAS) in connection with hematinic deficiency and atopy. Material and Methods. This cross-sectional study was conducted at Dr. Hasan Sadikin Hospital, Bandung, from January–March 2019 and was approved by the Health Research Ethics Committee of Universitas Padjadjaran (Ethics No. 990/UN6.KEP/EC/2018). Furthermore, the subjects had RAS ulcers with a history of at least twice a year along with atopy and dietary imbalance with no history of recurrent intraoral herpes or any systemic diseases. This study was performed on 23 RAS patients and 21 healthy subjects, and the sampling was carried out consecutively. The blood samples were collected from all the subjects, and then, the DNA and RNA were extracted from the peripheral blood mononuclear cells (PBMCs). Consequently, the bisulfite-modified DNA was used to confirm the methylation status of the IL6 gene promoter through the pyrosequencing method. The methylation levels of the IL6 promoter were assessed by a reverse transcriptase-polymerase chain reaction technique. The gene expression of RAS and the control group was analyzed by the 2^−ΔΔC_T method. The statistical analysis using the Mann–Whitney U test was conducted to evaluate IL6 mRNA levels and DNA methylation with p value <0.05 considered to be statistically significant.

Result

The IL6 mRNA levels were approximately 1.88-fold in RAS patients, and there was a significant relationship between the expression of the IL6 gene and the increased risk of RAS (p < 0.001). It was reported that four out of six sites in the cytosine phosphate guanine (CpG) island IL6 promoter had a lower degree of methylation, and two other sites in patients with RAS had greater methylation compared with control, but not statistically significant.

Conclusion

This study showed the upregulation of IL6 mRNA levels in RAS patients compared to control. DNA methylation in the present study is at sites 566–658, whereas the location of the IL6 promoter is at sites 1–1684. Thus, it would be necessary conducting some research at other CpG sites of IL6 promoter islands to determine the status of DNA methylation.

Analysis of Interleukin-1 Receptor Antagonist Variable Number Tandem Repeat Variant in Recurrent Aphthous Stomatitis

BACKGROUND/AIMS

Recurrent aphthous stomatitis (RAS) is one of the common oral inflammatory diseases. As immunological and genetic factors have been held responsible for the pathogenesis of RAS, the objective of this study was to determine whether the interleukin-1 receptor antagonist (IL-1Ra) gene variable number tandem repeat (VNTR) variant is a risk factor for the development of RAS in Turkish patients and to define its contribution to the increased risk.

METHODS

The IL-1Ra VNTR variant was evaluated in 169 RAS patients and 171 healthy controls by the polymerase chain reaction (PCR) method.

RESULTS

No statistically significant difference was found in the genotype distributions and allele frequencies of IL-1Ra VNTR variant between RAS patients and healthy controls.

CONCLUSION

Lack of association between IL-1Ra VNTR variant and RAS could indicate that IL-1Ra has no significant role in the pathophysiology of RAS. However, it still appears to be very worthwhile to continue to search for cytokine gene variants in order to predict the development of such disease.

Recurrent Aphthous Stomatitis in Children: A Practical Guideline for Paediatric Practitioners

Recurrent aphthous stomatitis (RAS) is the most common chronic oral mucosal lesion affecting up to 25% of the population. The diagnosis is based on well-defined clinical characteristics, but the precise aetiology and pathogenesis remain unclear. The treatment of RAS should be based on the identification and control of possible predisposing factors. A wide range of topical medicaments is available as antiseptics, anti-inflammatory drugs and corticosteroids. The systemic treatment is indicated in patients with continuous and aggressive manifestation, which is extremely rare in children. The present article provides a review of the current concept and knowledge of the aetiology, pathogenesis, and management of RAS in the paediatric population.

Success of dental implant osseointegration in a florid cemento-osseous dysplasia: A case report with 8-year follow-up

Florid cemento-osseous dysplasia (FCOD) is a rare benign fibro-osseous lesion which affects multiple quadrants and predominantly the mandible. This case report presents a successful implant placement with 8-year of follow-up in a 44-yearold woman asking for a fixed restoration in mandibular right posterior edentulous area. Radiographic images showed lobular, irregularly shaped radiopacities and radiolucencies almost symmetrically observed in the premolar-molar area of the right and left regions of the mandible. The findings of Xray images were attributable to FCOD. Minimally invasive two-stage surgery with strict infection control was followed to place two implants in lower right posterior region. The implants demonstrated clinically rigid fixation and restored successfully after 6 months. A direct functional connection between dysplastic bone and the implant load bearing surface was evidenced by the lack of symptoms, and the lack of soft tissues inflammation or peri-implant bone loss up to 8 years follow-up.

A family-based genome-wide association study of recurrent aphthous stomatitis

OBJECTIVES

The aetiology of recurrent aphthous stomatitis (RAS) remains unknown. Individuals may share features of genetic susceptibility, and there may also be a hereditary component. The aim was to identify patterns of association and segregation for genetic variants and to identify the genes and signalling pathways that determine the risk of developing RAS, through a family-based genome-wide association study (GWAS).

SUBJECTS AND METHODS

DNA was extracted from buccal swabs of 91 individuals in 16 families and analysed in an Illumina core exome single nucleotide polymorphism (SNP) array. A family-based association test (dFAM) was used to derive SNP association values across all chromosomes.

RESULTS

None of the final 288,452 SNPs reached the genome-wide significant threshold of 5 × 10^-8 . The most significant pathways were the Ras and PI3K-Akt signalling pathways, pathways in cancer, circadian entrainment and the Rap 1 signalling pathway.

CONCLUSIONS

This confirms that RAS is not monogenic but results as a consequence of interactions between multiple host genes and possibly also environmental factors. The present approach provides novel insights into the mechanisms underlying RAS and raises the possibility of identifying individuals at risk of acquiring this condition.

Oral Mucosal Injury Caused by Targeted Cancer Therapies

Targeted cancer therapies have fundamentally transformed the treatment of many types of cancers over the past decade, including breast, colorectal, lung, and pancreatic cancers, as well as lymphoma, leukemia, and multiple myeloma. The unique mechanisms of action of these agents have resulted in many patients experiencing enhanced tumor response together with a reduced adverse event profile as well. Toxicities do continue to occur, however, and in selected cases can be clinically challenging to manage. Of particular importance in the context of this monograph is that the pathobiology for oral mucosal lesions caused by targeted cancer therapies has only been preliminarily investigated. There is distinct need for novel basic, translational, and clinical research strategies to enhance design of preventive and therapeutic approaches for patients at risk for development of these lesions. The research modeling can be conceptually enhanced by extrapolating "lessons learned" from selected oral mucosal conditions in patients without cancer as well. This approach may permit determination of the extent to which pathobiology and clinical management are either similar to or uniquely distinct from oral mucosal lesions caused by targeted cancer therapies. Modeling associated with oral mucosal disease in non-oncology patients is thus presented in this context as well. This article addresses this emerging paradigm, with emphasis on current mechanistic modeling and clinical treatment. This approach is in turn designed to foster delineation of new research strategies, with the goal of enhancing cancer patient treatment in the future.

Interleukin-4 and Interleukin-4 Receptor Alpha Gene Polymorphisms in Recurrent Aphthous Stomatitis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common oral condition with a major impact on the quality of life. The condition is thought to be due to the overexpression of T helper-1(Th1)-related cytokines. Since interleukin-4 (IL-4) and its receptor (IL-4Rα) are antagonistic to Th-1 pathways, polymorphisms in their genes may also be involved in the pathogenesis of aphthous stomatitis.

METHODS

Sixty-four patients diagnosed with minor RAS and 141 (age- and sex-matched) healthy controls were assessed for 3 single-nucleotide polymorphisms (SNPs) within the promoter region of the IL-4 gene (-1098G/T, -590C/T, and -33C/T), and 1 SNP in IL-4Rα gene (+1902 A/G).

RESULTS

No significant differences were detected between the patient and the control group regarding IL-4 allele frequencies. However, the patient group demonstrated a higher frequency of IL-4 -590 CC genotype and a lower rate of IL-4 -590 TC genotype. The TCT, GTT, GCT, and GTC haplotypes of the IL-4 gene (-1098, -590, -33) were significantly more frequent in the patients and the GCC, and TTT haplotypes were more common in healthy controls. No significant differences were found in IL-4Rα gene polymorphism between the 2 groups.

CONCLUSIONS

Certain polymorphisms of IL4 gene could predispose individuals to RAS.

The association between interleukin polymorphism and recurrent aphthous stomatitis: A meta-analysis

OBJECTIVE

To assess the association between interleukin gene polymorphism and recurrent aphthous stomatitis (RAS).

DESIGNS

Two electronic databases, PubMed and Embase, were utilized to assemble potentially relevant studies meeting the inclusion criteria. A meta-analysis was conducted using Revman 5.3 software (London, UK), and the pooled odds ratio (OR) and 95% confidence interval (CI) were then used to evaluate the strength of the relationship between the gene polymorphisms of IL-1beta(-511C/T), IL-1beta(+3954C/T), IL-6(-174G/C) and IL-10(-1082G/A) and the risk of RAS.

RESULTS

Ten studies were included in the final meta-analysis, with 884 cases and 1104 controls participating. The results demonstrated that the polymorphism of IL-1beta(-511C/T) significantly increased the probability of the development of RAS in Europeans. (T vs. C: OR = 1.35, 95%CI = 1.09-1.67; CC vs. CT + TT: OR = 1.77, 95%CI = 1.24-2.53; CC vs. TT: OR = 1.86, 95%CI = 1.18-2.95). Furthermore, the C allele in IL-1beta(+3954C/T) was determined to be related to the risk of RAS in Americans (C vs. T: OR = 1.52, 95%CI = 1.07-2.17) and the presence of the C gene was considered a risk variant (CC + CT vs. TT: OR = 1.46, 95%CI = 1.01-2.11), but no relationship was found between the polymorphism of IL-10(-1082G/A) and the risk of RAS.

CONCLUSIONS

The meta-analysis suggested that the mutation of IL-1beta(-511C/T) in Europe and IL-1beta(+3954C/T) in America tend to increase the risk of RAS, but the polymorphism of IL-10(-1082G/A) appears to have no association with RAS risk in America. Further study is required to confirm the above conclusions.

Associations of IL-1, 6, and 10 Gene Polymorphisms with Susceptibility to Recurrent Aphthous Stomatitis: Insights from a Meta-Analysis

AIM

To determine if there are significant associations between polymorphisms of the IL-1, IL-6, and IL-10 genes and susceptibility to recurrent aphthous stomatitis (RAS).

METHODS

The PubMed, Embase, and Web of Science databases were searched for all eligible studies using both medical subheadings and free terms through December 2016. A total of 226 citations were retrieved. Odds ratios were used to quantitatively evaluate the associations of IL-1, IL-6, and IL-10 gene polymorphisms with RAS risk. A meta-analysis was performed, and heterogeneity, sensitivity, and subgroup analyses were carried out to clarify and validate the pooled results.

RESULTS

A total of 11 studies were identified that met the inclusion criteria and were included in the meta-analysis. This current systematic review indicated that the IL-1b+3954 C/T polymorphism was significantly associated with an elevated risk of RAS onset for all inheritance models, except for the dominant model. For the IL-10-592 C/A polymorphism, protective associations with RAS were found using both the additive and recessive models, while it increased the risk of RAS in the codominant model. In Asian populations, the IL-10-1082 G/A polymorphism was associated with a protective effect for RAS using the allelic, additive, and recessive models. The IL-6-174 G/C polymorphism was not statistically associated with RAS risk.

CONCLUSION

The IL-1b+3954 C/T polymorphism significantly increases RAS risk. In addition, the IL-10-1082 G/A polymorphism provided protective effects for RAS in the Asian population.

Salivary metabolomics profile of patients with recurrent aphthous ulcer as revealed by liquid chromatography-tandem mass spectrometry

Objective We compared the salivary nontargeted metabolite profiles between patients with recurrent aphthous ulcer (RAU) and healthy individuals to investigate the metabolic alterations associated with RAU. Methods Saliva samples were collected from 45 patients with RAU and 49 healthy individuals, and the salivary metabolites were quantified using liquid chromatography-tandem mass spectrometry. The metabolomic profiles were then analyzed using multivariate and univariate statistical methods, and enrichment of the metabolites in various biological pathways was assessed. Results In total, 206 significant differentiating metabolites (Wilcoxon test, false discovery rate [FDR] of <0.05) were identified between patients with RAU and healthy individuals. These metabolites were implicated in tryptophan metabolism, steroid hormone biosynthesis, and other metabolic pathways. Two commonly circulating steroids, estrone sulfate and dehydroepiandrosterone sulfate, were significantly lower in the saliva of patients with RAU (Wilcoxon test, FDR < 0.05, power > 0.9). Principal component analysis and partial least-squares discriminant analysis revealed metabolic perturbations involving RAU, and receiver operating characteristic curve analysis with several metabolites showed good diagnostic ability for RAU. Conclusions The results of this study indicate that patients with RAU are characterized by metabolic imbalances. Psychogenic factors, endocrinopathies, and immunosuppression may contribute to the onset of RAU.

Successful Implant Placement in a Case of Florid Cemento-Osseous Dysplasia: A Case Report and Literature Review

Florid cemento-osseus dysplasia (FCOD) has been described as a reactive process in which normal bone is replaced by fibrous connective tissues and cementum-like materials. Radiographically it appears as dense, lobulated masses, often occurring bilaterally with symmetric involvement. In this case report, a successful implant placement has been reported in a 62-year-old Caucasian woman with a chief complaint of mandibular partial edentulous. Radiographic images showed the bilateral radiopaque lesions in edentulous regions of mandible, and mandibular anterior teeth alike. All mandibular teeth were vital and no root resorption was detected. The findings of X-ray images were attributable to FCOD. A highly conservative step-by-step 2-stage implant surgery was performed. After 6 months the implants loaded with fixed prosthesis. 2, 4, 6, 12, and 18 months after the surgery radiographic images were taken, which revealed an optimal functional rehabilitation and complete integration of implants. This report confirms that treating the edentulous area near the FCOD lesions could be planned, if conservative step- by-step implant placement been considered. To the best of our knowledge, a case of FCOD with successful implant placement has not been reported previously. More studies in more patients are needed to confirm results of such a therapeutic modality.

Recurrent aphthous ulceration: a review of potential causes and novel treatments

Purpose of article: This review examines studies published between May 2012 and 2017 with a specific interest in potential recurrent aphthous ulceration (RAU) etiologies and treatment modalities/efficacy, including topical treatments, systemic regimens, vitamin repletion, and laser therapy, among others.

MATERIALS AND METHODS

PubMed MEDLINE and Cochrane Database of Systematic Reviews were searched using various combinations of: 'aphthous', 'ulcer', and 'treatment'. The titles and abstracts from the initial literature search were appraised to identify articles for full review and reference sections from each article were searched manually for relevant publications. Both randomized controlled trials and observational reports were included in this review, as some treatment types have not been formally examined in randomized trials. Relevant studies were reviewed, compared, and summarized.

RESULTS

RAU can result from systemic disease and trauma, but recent studies have shown a variety of potential etiologies, ranging from vitamin deficiencies, oral microbiota derangements, hematological considerations, stress, genetic polymorphisms to oxidant-antioxidant imbalances, among others. Many modalities of therapy are available and have proven efficacious.

CONCLUSIONS

As the exact etiology of RAU is still unknown, therapy is based on symptomatic relief.

Systemic bioinformatics analysis of recurrent aphthous stomatitis gene expression profiles

Recurrent aphthous stomatitis (RAS) represents the most common chronic oral diseases with the prevalence ranges from 5% to 25% for different populations. Its pathogenesis remains poorly understood, which limits the development of effective drugs and treatment methods. In this study, we conducted systemic bioinformatics analysis of gene expression profiles from the Gene Expression Omnibus (GEO) to identify potential drug targets for RAS. We firstly downloaded the gene microarray datasets with the accession number of GSE37265 from GEO and performed robust multi-array (RMA) normalization with affy R programming package. Secondly, differential expression genes (DEGs) in RAS samples compared with control samples were identified based on limma package. Enriched gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of DEGs were obtained through the Database for Annotation, Visualization and Integrated Discovery (DAVID). Finally, protein-protein interaction (PPI) network was constructed based on the combination of HPRD and BioGrid databases. What’s more, we identified modules of PPI network through MCODE plugin of Cytoscape for the purpose of screening of valuable targets. As a result, 915 genes were found to be significantly differential expression in RAS samples and biological processes related to immune and inflammatory response were significantly enriched in those genes. Network and module analysis identified FBXO6, ITGA4, VCAM1 and etc as valuable therapeutic targets for RAS. Finally, FBXO6, ITGA4, and VCAM1 were further confirmed by real time RT-PCR and western blot. This study should be helpful for the research and treatment of RAS.

Association of IL-6-174 G/C and IL10-1082 G/A polymorphisms with recurrent aphthous stomatitis risk: A meta-analysis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common oral disease with unknown etiology. The association between IL-6-174 G/C and IL10-1082 G/A polymorphisms and the risk of RAS remains controversial. Therefore, we conducted this meta-analysis to gain more evidence-based information.

METHODS

Four online databases, PubMed, Embase, Web of Science, and Cochrane Library, were searched, and the relevant publications were collected. An odds ratio (OR) with a 95% confidence interval (CI) was applied to assess the association of the IL-6-174 G/C and IL10-1082 G/A polymorphisms with RAS susceptibility.

RESULTS

Nine published case-control studies with 779 patients and 1016 controls were collected. The overall analysis proved that the IL10-1082 G/A polymorphism was significantly associated with the risk of RAS in a dominant model (GG + AG vs AA: OR = 1.49, 95% CI = 1.10-2.01, P = .01). A subgroup analysis based on ethnicity revealed significant associations in Asian populations in allelic, heterozygote, and dominant models (G vs A: OR = 1.55, 95% CI = 1.04-2.31, P = .03; AG vs AA: OR = 1.76, 95% CI = 1.16-2.67, P = .01; GG + AG vs AA: OR = 2.04, 95% CI = 1.37-3.03, P = .00). The association in Caucasians and people of mixed ethnicity requires further study. No significant association was detected between the IL-6-174 G/C polymorphism and RAS in any of the genetic models. However, subgroup analysis by ethnicity revealed that the Caucasians were more likely to develop RAS in 4 genetic models (G vs C: OR = 2.36, 95% CI = 1.26-4.41, P = .01; GG vs CC: OR = 7.05, 95% CI = 3.50-14.18, P = .00; GG + CG vs CC: OR = 4.28, 95% CI = 2.17-8.45, P = .00; GG vs CG + CC: OR = 2.59, 95% CI = 1.05-6.41, P = .04). In addition, a significantly decreased risk of RAS susceptibility was found in Asians (CG vs CC: OR = 0.27, 95% CI = 0.07-0.99, P = .049; GG + CG vs CC: OR = 0.27, 95% CI = 0.07-0.98, P = .047).

CONCLUSION

Our meta-analysis indicated that the IL10-1082 G/A polymorphism is associated with RAS susceptibility, especially in Asians. In contrast, the IL-6-174 G/C polymorphism does not have a statistically significant association with RAS susceptibility. However, it may play a different role during the development of RAS in different ethnicities.

Preventive effects of mouthguard use while sleeping on recurrent aphthous stomatitis: Preliminary interventional study

Recurrent aphthous stomatitis (RAS) is the most common inflammatory ulceration in the oral mucosa of otherwise healthy individuals and is often accompanied by severe pain. However, the etiology of RAS is not completely understood, and currently, no therapy can completely prevent RAS recurrence. In our clinical experience, we noticed that patients using a night guard, which is often used for bruxism treatment, did not develop RAS. Therefore, the aim of this study was to determine whether mouthguard use can suppress RAS development. The cohort of this interventional, prospective, single-center, and self-controlled study included 20 subjects who developed RAS at least once a month. The oral health of all the subjects was recorded for 60 days before and after intervention with a mouthguard. The average number of RAS incidences decreased from 5.5 to 1.0, the average days until healing decreased from 7.3 to 5.6, and the period with RAS decreased from 31.5 to 5.0 with mouthguard use. Mouthguard use may be beneficial for preventing RAS development.

The absence of an association between Interleukin 1β gene polymorphisms and recurrent aphthous stomatitis (RAS)

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a chronic, ulcerative disease with a probable polygenic mode of inheritance and complex etiology with a strong immunological background. The aim of the present study was to determine the possible association between two single nucleotide polymorphisms (SNPs) of the IL-1β gene: IL-1β-511 T>C (rs16944) and IL-1β+3954C>T (rs1143634) and RAS susceptibility in a moderately large group of patients.

DESIGN

One hundred and four patients with minor, major and herpetiform RAS and 75 healthy volunteers were genotyped at IL-1β-511 T>C (rs16944) and IL-1β+3954C>T (rs1143634) using the PCR-RFLP approach. The results were statistically analysed with chi-square test and test of difference between two rates of structure, with p<0.05 assumed to be a statistically significance level (Statistica 10, StatSoft^®, Kraków, Poland).

RESULTS

There were no statistically significant differences in the genotype distribution for the IL-1β C[+3954]T polymorphism between the RAS and control groups. The frequency of IL-1β*T[-511]/*T[-511] homozygotes among the patients was significantly higher when compared to our study control (p<0.0347). The results after stratification into carriers and non-carriers of C and T alleles did not clearly indicate which SNP may be considered a risk factor for RAS.

CONCLUSIONS

The genetic association between the studied SNPs of the IL-1β gene and RAS remains controversial and requires further investigation.

Interleukin-2, Interferon-gamma Gene Polymorphisms in Recurrent Aphthous Stomatitis

Recurrent aphthous stomatitis (RAS) is the most common oral ulcerative inflammatory disease with unknown etiology. IL-2 and IFN-γ are secreted by Th1 cells and the elevated levels of them have been reported in RAS. Single nucleotide polymorphisms (SNPs) of IL-2 and IFN-γ genes could alter the cytokine production. The aim of this study was to investigate frequencies of IL-2 and IFN-γ alleles and genotypes in a group of patients with minor-RAS (MiRAS). PCR-SSP method used to type genomic DNA of 64 Iranian patients with MiRAS for IL-2 gene (G –330 T) and (G +166 T) and IFN-γ gene at position UTR5644 (A/T). Frequency of each allele and genotype was compared with control group. IL-2 +166 G allele was significantly lower among patients which was reflected in significantly decreased of GG genotype at this position, while IL-2 +166 T allele was significantly higher among patients, IL-2 GT genotype was also significantly higher in RAS patients. No significant differences were found regarding IL-2 –330 G/T allele frequencies, while IL-2 GT genotype at this position was significantly higher among patients and IL-2 –330 TT genotype was significantly lower among RAS patients. Although no significant differences were found in IFN-γ allele frequencies at UTR5644 (A/T), AT genotype at this position was significantly overrepresented among patients compared with controls. Results of this study suggest that certain SNPs of IL-2 and IFN-γ genes have association with predisposition of individuals to RAS. More studies in different ethnic groups are needed to confirm results of this study.

Association study of interleukin-1 family, interleukin-6, and its receptor gene polymorphisms in patients with recurrent aphthous stomatitis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is one of the most common oral chronic ulcerative disease in which proinflammatory cytokines such as interleukin-1 (IL-1) and interleukin-6 (IL-6) are thought to play an important role. The aim of this study was to investigate the possible association between polymorphisms in the IL-1 cytokine family, IL-6 or its receptor and RAS in the Czech population.

METHODS

A total of 248 subjects, 184 healthy controls, and 64 patients with RAS were genotyped for IL-1A-889C>T, IL-1B-511C>T, IL-1B+3953C>T, IL-1RN86 bp variable number of tandem repeats (VNTRs) in intron 2, IL-6-597G>A, IL-6-572G>C, IL-6-174G>C, and IL-6R+48992A>C by polymerase chain reaction (PCR) methods.

RESULTS

No significant differences between investigated polymorphisms in healthy subjects and patients with RAS were detected (P>.05). In addition, complex analysis also revealed similar IL-1 or IL-6 haplotype frequencies between both groups (P>.05).

CONCLUSIONS

In conclusion, IL-1 and IL-6 or its receptor gene variants cannot be used as markers for identification of Czech patients with increased risk of recurrent aphthous stomatitis.