Serotonin transporter gene polymorphism (5-HTTLPR) in patients with recurrent aphthous stomatitis

Recurrent Oral Ulcers and Its Association With Stress Among Dental Students in the Northeast Indian Population: A Cross-Sectional Questionnaire-Based Survey

Aim The term "aphthous" is derived from the Greek word "aphtha," which means ulceration. The cause of aphthous ulcers is multifactorial, but emotional stress is one of the most important risk factors for its occurrence in young individuals. The aim of this study was to evaluate the association of recurrent oral ulcers (ROUs) with stress among dental students in the Northeast Indian Population. Materials and methods A total of 1,134 students were recruited for the study. Two sets of questionnaires were designed. The first set consisted of 11 questions related to demographic data and information about recurrent oral ulcers. The second set of questionnaire had 14 questions related to stress symptoms. Google Forms (Google, Inc., Mountain View, CA, USA) was used for recording the responses of the study participants. Questionnaires were sent to the participants through e-mail, and responses were recorded. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 21 (IBM SPSS Statistics, Armonk, NY, USA) and Microsoft Office Excel (Microsoft Corp., Redmond, WA, USA). The chi-square test was used to compare categorical variables. Results Among the 1,134 participants, 32.7% (371 students) reported a previous history of recurrent oral ulcers. Out of 371 participants who had given a history of oral ulcers, only 27.2% exhibited direct stress to ulcer association. On further assessment using the Perceived Stress Scale (PSS), it was found that a far greater percentage of students (i.e., more than 27.2%) were under some form of stress or the other. Conclusions The results of this study will help improve the quality of life among the study population, either by tackling their stress levels or by identifying adequate interventions.

Insight into the Role of Psychological Factors in Oral Mucosa Diseases

With the development of psychology and medicine, more and more diseases have found their psychological origins and associations, especially ulceration and other mucosal injuries, within the digestive system. However, the association of psychological factors with lesions of the oral mucosa, including oral squamous cell carcinoma (OSCC), burning mouth syndrome (BMS), and recurrent aphthous stomatitis (RAS), have not been fully characterized. In this review, after introducing the association between psychological and nervous factors and diseases, we provide detailed descriptions of the psychology and nerve fibers involved in the pathology of OSCC, BMS, and RAS, pointing out the underlying mechanisms and suggesting the clinical indications.

Exploring the Relationship Between Psychiatric Traits and the Risk of Mouth Ulcers Using Bi-Directional Mendelian Randomization

Background

Although the association between mouth ulcers and psychiatric traits has been reported by observational studies, their causal relationship remains unclear. Mendelian randomization (MR), powered by large-scale genome-wide association studies (GWAS), provides an opportunity to clarify the causality between mouth ulcers and psychiatric traits.

Methods

We collected summary statistics of mouth ulcers (sample size n = 461,106) and 10 psychiatric traits from the largest publicly available GWAS on Europeans, including anxiety disorder (n = 83,566), attention deficit/hyperactivity disorder (n = 53,293), autism spectrum disorder (n = 46,350), bipolar disorder (n = 51,710), insomnia (n = 1,331,010), major depressive disorder (n = 480,359), mood instability (n = 363,705), neuroticism (n = 168,105), schizophrenia (n = 105,318), and subjective wellbeing (n = 388,538). We applied three two-sample bi-directional MR analysis methods, namely the Inverse Variance Weighted (IVW) method, the MR pleiotropy residual sum and outlier (MR-PRESSO) method, and the weighted median method, to assess the causal relationship between each psychiatric trait and mouth ulcers.

Results

We found significant effects of autism spectrum disorder, insomnia, major depressive disorder, and subjective wellbeing on mouth ulcers, with the corresponding odds ratio (OR) from the IVW method being 1.160 [95% confidence interval (CI): 1.066–1.261, P = 5.39 × 10^–4], 1.092 (1.062–1.122, P = 3.37 × 10^–10), 1.234 (1.134–1.342, P = 1.03 × 10^–6), and 0.703 (0.571–0.865, P = 8.97 × 10^–4), respectively. We also observed suggestive evidence for mood instability to cause mouth ulcers [IVW, OR = 1.662 (1.059–2.609), P = 0.027]. These results were robust to weak instrument bias and heterogeneity. We found no evidence on causal effects between other psychiatric traits and mouth ulcers, in either direction.

Conclusion

Our findings suggest a protective effect of subjective wellbeing and risk effects of autism spectrum disorder, insomnia, major depressive disorder, and mood instability on mouth ulcers. These results clarify the causal relationship between psychiatric traits and the development of mouth ulcers.

Investigation of CD40 gene rs4810485 and rs1883832 mutations in patients with recurrent aphthous stomatitis

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a common painful disorder affecting oral health, mucosa and overall quality of life. The etiopathogenesis of RAS remains unclear. RAS shows a large genetic diversity among the patients. In present study, we investigated whether CD40 gene rs4810485 and rs1883832 are associated with RAS and its clinical findings in Turkish patients.

MATERIALS AND METHODS

Genomic DNA obtained from 387 individuals (160 patients with RAS and 227 healthy controls) were used in the study. CD40 gene rs4810485 and rs1883832 mutations were determined by using polymerase chain reaction with the specific primers.

RESULTS

There was no statistically significant difference between the groups with respect to genotype and allele distribution (p>0.05, OR 0.94, 95% CI 0.70-1.28, OR 1.01 95% CI 0.75-1.37, respectively). Additionally, there was no statistically significant difference in the combined genotype analysis of CD40 gene rs4810485 and rs1883832 mutations (p>0.05).

CONCLUSIONS

According to our results, we found that CD40 gene mutations are not associated with RAS. We are convinced that CD40 gene mutations do not predispose to develop RAS in Turkish population. To our knowledge, this is the first study regarding CD40 gene rs4810485 and rs1883832 mutations investigated in RAS patients.

Association between serotonin transporter gene polymorphism and recurrent aphthous stomatitis

Background:

Anxiety-related traits have been attributed to sequence variability in the genes coding for serotonin transmission in  the brain. Two alleles, termed long (L) and short (S) differing by 44 base pairs, are found in a polymorphism identified in the promoter region of serotonin transporter gene. The presence of the short allele  and SS and LS genotypes is found to be associated with the reduced expression of this gene decreasing the uptake of serotonin in the brain leading to various anxiety-related traits. Recurrent aphthous stomatitis (RAS) is an oral mucosal disease with varied etiology including the presence of stress, anxiety, and genetic influences. The present study aimed to determine this serotonin transporter gene polymorphism in patients with RAS and compare it with normal individuals.

Materials and Methods:

This study included 20 subjects with various forms of RAS and 20 normal healthy age- and gender-matched individuals. Desquamated oral mucosal cells were collected for DNA extraction and subjected to polymerase chain reaction for studying insertion/deletion in the 5-HTT gene-linked polymorphic region. Cross tabulations followed by Chi-square tests were performed to compare the significance of findings, P < 0.05 was considered statistically significant.

Results:

The LS genotype was the most common genotype found in the subjects with aphthous stomatitis (60%) and controls (40%). The total percentage of LS and SS genotypes and the frequency of S allele were found to be higher in the subjects with aphthous stomatitis as compared to the control group although a statistically significant correlation could not be established, P = 0.144 and 0.371, respectively.

Conclusion:

Within the limitations of this study, occurrence of RAS was not found to be associated with polymorphic promoter region in serotonin transporter gene.

Anxiety, Depression and Quality of Life among Patients with Recurrent Aphthous Ulcers

BACKGROUND

Recurrent aphtous ulcers (RAUs) are of the most painful and common oral mucosal diseases with uncertain etiology including trauma, genetics, stress, immune dysfunction, and vitamin deficiencies. The aim of this study was to investigate the relationship between oral health impacts, patients' oral health-related quality of life and anxiety and depression in patients with recurrent aphtous ulcers.

SUBJECTS AND METHODS

Sixty patients were diagnosed RAU (30 men and 30 women, mean age: 29.5 ± 9.6 years) and sixty controls, who matched the patients with age and gender, participated in this study. Participants completed hospital anxiety and depression (HAD) scale, oral health impact profile (OHIP-14), and United Kingdom oral health related quality of life measure (OHQoL-UK). The statistically significance levels were set at p ≤ 0.05.

RESULTS

Both patients and controls reported comparable depression and anxiety scores (p > 0.05). Ulcer patients reported worse oral health impacts and inferior quality of life in comparison to controls (p < 0.001). Among both groups, no relationships were detected between HAD scores on one hand and OHIP and/or OHQoL-UK on the other hand (p > 0.05).

CONCLUSIONS

Recurrent aphthous ulcers increase the negative oral health impacts on patients and consequently cause inferior quality of life. Stressful situations and conditions (including anxiety and depression) were not related to oral health impacts and quality of life in patients with RAUs.

Prevalence of recurrent aphthous ulceration in the Indian Population

Objective: Patients with an oral ulcer may present initially to a general physician or a dental practitioner. Majority of the ulcers are benign and resolve spontaneously but small proportions are malignant. The aim of the present study was to determine the prevalence of recurrent aphthous ulcerations in the Indian population. Material and Methods: 3244 patients attending the Department of Oral Medicine and Radiology during the period from November, 2010 to December, 2012 with various complaints were examined. Of the patients examined 1669 were females and 1575 were males. Results: 705 patients presented with recurrent aphthous ulceration (21.7%). Females (56.3%) were more commonly affected than males (43.7%). Patients in the third and fourth decade were most commonly affected. Stress was the most common factor associated with recurrent aphthous stomatitis (386 patients). 54.5% patients did not take any medications and 72.9% patients opined that the condition needed no dental consultation. Conclusion: The results of the present study indicate that recurrent aphthous ulceration is a common mucosal disorder in the Indian population. The early and proper diagnosis of the ulcers will help the dental practitioner in providing information to the patient regarding awareness and management of the condition.

Key words:Recurrent aphthous ulcers, prevalence, Indian population.

Etiopathogenesis of recurrent aphthous stomatitis and the role of immunologic aspects: literature review

Recurrent aphthous stomatitis (RAS; recurrent aphthous ulcers; canker sores) belongs to the group of chronic, inflammatory, ulcerative diseases of the oral mucosa. Up to now, the etiopathogenesis of this condition remains unclear; it is, however, considered to be multifactorial. The results of currently performed studies indicate that genetically mediated disturbances of the innate and acquired immunity play an important role in the disease development. Factors that modify the immunologic response in RAS include: food allergies, vitamin and microelement deficiencies, hormonal and gastrointestinal disorders (e.g., celiac disease, Crohn’s disease, ulcerative colitis), some viral and bacterial infections, mechanical injuries and stress. In this paper, we presented the main etiopathogenetic factors of RAS with a special emphasis on the mechanisms of the immune response modification. Moreover, we discussed the crucial clinical symptoms and types of RAS together with epidemiologic data based on the current medical literature reports and our own observations.

Association between interleukin 4 gene intron 3 VNTR polymorphism and recurrent aphthous stomatitis in a cohort of Turkish patients

OBJECTIVE

Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal diseases, with a multifactorial etiopathogenesis, an interaction between predisposing factors and/or systemic conditions and immunological components in genetically predisposed subjects. Although there is no clear genetic mode of inheritance, there is evidence that inheritance of specific gene polymorphisms may predispose individuals to RAS. The purpose of the present study was to investigate a possible association between the functional interleukin 4 (IL4) VNTR genetic polymorphism and RAS in a sample of Turkish patients.

METHODS

The study included 145 unrelated patients with a clinical diagnosis of RAS and 150 unrelated healthy controls. Genomic DNA was isolated and IL4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers.

RESULTS

The distribution of genotype and allele frequencies of IL4 gene intron 3 VNTR polymorphism was statistically different between RAS patients and control group (p<0.0001 and p<0.0001, respectively) P2P2 genotype and P2 allele were also found to be protective with a lower risk for susceptibility to RAS (p<0.0001).

CONCLUSION

The results of this study suggest that intron 3 VNTR polymorphism in the IL4 gene is associated with RAS susceptibility in Turkish population.

Recurrent aphthous stomatitis: genetic aspects of etiology

Recurrent aphthous stomatitis (RAS; recurrent aphthous ulcers - RAU; canker sores) is a chronic inflammatory, ulcerative condition of the oral mucosa. Its prevalence in the general population ranges between 5% and 20%, depending on the method and group studied. The etiopathogenesis of the disease is considered to be multifactorial, but remains still not fully understood. In patients with RAS, an enhanced immunologic response occurs to some trigger factors that may include: mechanical injury, stress or bacterial and viral antigens. Higher prevalence of aphthae in relatives may also indicate the genetic background of the condition. The inheritance of some specific gene polymorphisms, especially those encoding proinflammatory cytokines, which play a role in the formation of aphthous ulcer, may predispose family members to RAS. The purpose of this paper was to present the main clinical features of recurrent aphthous stomatitis, epidemiologic data and crucial etiopathogenetic factors with a special emphasis on genetic background of the condition.

Analysis of the normative conditions of oral health, depression and serotonin-transporter-linked promoter region polymorphisms in an elderly population

AIM

To investigate the association between depression, the normative conditions of oral health and serotonin-transporter-linked promoter region (5-HTTLPR) polymorphisms in a community-dwelling elderly sample.

METHODS

Elderly adults living in a community (n=200) were submitted to an oral clinical examination. Depression was assessed using the 15-item Geriatric Depression Scale. The 5-HTTLPR was analyzed by polymerase chain reaction-restriction fragment length polymorphism. Associations between the biomarkers and clinical covariates were assessed by bivariate and multivariate statistical tests. Statistical significance was set at P<0.05.

RESULTS

The prevalence of dental caries, periodontal disease, edentulism and oral mucosal lesions was 51.2%, 20.8%, 58.0% and 21.5%, respectively. The prevalence of depression was 21.5%. A higher frequency of the S allele was recorded in older individuals with depression (P=0.017). The present findings showed no significant association between depression and the normative conditions of oral health. The observed allelic polymorphisms were 44% S and 56% L, respectively. Genotypic variants were 33.5% LL, 45.0% SL and 21.5% SS. Individuals carrying the SS genotype showed a significantly high prevalence of periodontal disease (prevalence ratio=3.077, CI 95%=1.008-9.393, P=0.048).

CONCLUSION

The present findings suggest that depressive community-dwelling older individuals did not show any association with alterations of oral health normative conditions. However, the SS genotypic polymorphic variant of 5-HTTLPR seems to contribute to the occurrence of periodontal disease in the elderly.

Serotonin transporter gene polymorphisms: a case-control study

Considerable evidence indicates that serotonergic mechanisms, particularly the serotonin transporter, are involved in alcoholism and tobacco use and are influenced by polymorphism of the promoter region of 5HTT (5-HTTLPR). As alcohol and tobacco consumption have been implicated in the pathogenesis of oral cancer, the purpose of this study was to investigate 5-HTTLPR polymorphism in patients with oral squamous cell carcinoma (OSCC) compared with a control group in a sample of Brazilian patients. One hundred and three patients affected by OSCC and 103 volunteers without OSCC were genotyped for 5-HTTLPR. Both groups were matched for age, sex and tobacco use. The chi-squared test was used for statistical analysis (α=0.05). There was no statistically significant difference in 5-HTTLPR genotypes between case and control group (p= 0.408). In conclusion, the present investigation demonstrated that serotonin transporter polymorphisms are not implicated in the OSSC development.

Effect of stressful life events on the onset and duration of recurrent aphthous stomatitis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common and painful oral mucosal disease. Possible etiologies include genetics, vitamin deficiencies, trauma, immune dysfunction, and stress. The goal of this study was to examine the relationship between the occurrence, type, and magnitude of stressful events and the onset and duration of RAS episodes.

METHODS

One hundred and sixty subjects with a history of RAS completed a weekly phone survey for up to 1 year, providing data on the occurrence of RAS episodes and details of any stressful events they experienced during the previous week. During RAS episodes, subjects also completed daily paper diaries that recorded incidence and duration of the RAS episode. Stressful events were quantified using the validated Recent Life Changes Questionnaire (RLCQ) and were classified as mental or physical stressors.

RESULTS

Stressful life events were significantly associated with the onset of RAS episodes (P < 0.001), however, not with the duration of the RAS episodes. Experiencing a stressful life event increased the odds of an RAS episode by almost three times (OR = 2.72; 95% CI = 2.04-3.62). When controlled for each other, mental stressors had a larger effect (OR = 3.46, 95% CI = 2.54-4.72) than physical stressors (OR = 1.44; 95% CI = 1.04-1.99) on the occurrence of RAS episodes. RAS episodes did not occur more frequently or last longer with increasing stress severity.

CONCLUSIONS

In patients with a history of RAS, stressful events may mediate changes involved in the initiation of new RAS episodes. Mental stressors are more strongly associated with RAS episodes than physical stressors.

Possible Association between Th1 Immune Polarization and Epithelial Permeability with Toll-Like Receptors 2 Dysfunction in the Pathogenesis of the Recurrent Aphthous Ulceration

Recurrent Aphthous Ulceration (RAU) is a chronic oral inflammatory disease that affects approximately 25% of the general population. The etiology of the disease is unknown; however, factors that favor the onset of RAU have been correlated with a Th1 immune polarization, while factors that reduce RAU episodes have been associated with down regulation of immune reaction or stimulation of the peripheral tolerance. In this context, the integrity of the epithelial barrier is also fundamental for the prevention of the disease and conditions that augment its permeability or produce disruption are considered potential triggers. The key factor responsible for increased susceptibility is unclear, though a deficiency of Toll-like receptor (TLR) activity seems to be a good candidate. TLRs are a group of membrane proteins that recognize conserved molecules derived from bacterial, virus, fungal, or host tissues. Particularly, the TLR2 is involved in both immune regulation and control of epithelial barrier integrity. Thus, based on literature review, we showed evidences that correlate the TLR2 dysfunction and the diverse predisposing factors with the elements considered critical for disease pathogenesis: the Th1 immune reaction and the increased epithelial permeability.

Serotonin transporter gene polymorphism (5-HTTLPR) in patients with oral lichen planus

BACKGROUND

Considerable evidence indicates that serotonergic mechanisms, particularly the serotonin transporter (5-HTT) may be involved in psychiatric alterations. Recent findings have demonstrated that depression and stress are influenced by polymorphism of the promoter region of 5-HTT (5-HTTLPR) and that the short allele (S) is associated with reduced transcriptional efficiency resulting in reduced serotonin expression and uptake. As psychiatric and genetic factors have been implicated in the pathogenesis of oral lichen planus (OLP), the purpose of the present study was to investigate 5-HTTLPR polymorphism in patients with OLP compared to control subjects.

SUBJECTS AND METHODS

Fifty-four subjects affected by OLP and 54 healthy volunteers were genotyped at 5-HTTLPR. The chi-squared test was used for statistical analysis. To investigate the association between the single nucleotide polymorphisms and risk of OLP, binary logistic regression models were fitted.

RESULTS

No statistical difference was observed between the genotype and allele frequency in the group of OLP and controls (p=0.51). Moreover no association between 5HTTLPR alleles and OLP was found in the multivariate analyses.

CONCLUSION

Our study demonstrates that polymorphism on the 5-HTTLPR is not associated with OLP pathogenesis.

Investigation of functional gene polymorphisms IL-1β, IL-6, IL-10 and TNF-α in individuals with recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is characterized by recurrent episodes of oral ulceration in an otherwise healthy individual. Some reports in the literature indicate that RAS may have immunological, psychological, genetic and microbiological bases.

OBJECTIVE

The purpose of the present study was to investigate, using binary logistic regression analyses, a possible association between the functional IL-1beta +3954 (C/T), IL-6 -174 (G/C), IL-10 -1082 (G/A) and TNF-alpha -308 (G/A) genetic polymorphism and RAS in a sample of Brazilian patients, using a multivariate statistical analysis.

DESIGN

Sixty-four consecutive subjects affected by minor and major forms of RAS and 64 healthy volunteers were genotyped. To investigate the association between the single nucleotide polymorphisms and risk of RAS, binary logistic regression models were fitted. The associations were expressed by odd ratios (ORs) and adjusted for age and gender, with the corresponding 95% CIs. P-values less than 0.05 were considered significant.

RESULTS

A significant increase in the IL-1beta and TNF-alpha heterozygous genotypes were associated with an increased risk of RAS development (OR 2.40 and 3.07, respectively), in the multivariate model.

CONCLUSION

Our findings demonstrate that polymorphisms of high IL-1beta and TNF-alpha production were associated with an increased risk of RAS development. Our findings also give additional support to a genetic basis for RAS pathogenesis.

Association of interleukin-1? polymorphism with recurrent aphthous stomatitis in Brazilian individuals

BACKGROUND

Recurrent aphthous stomatitis (RAS) is characterized by recurrent episodes of oral ulceration in an otherwise healthy individual. Some reports in the literature indicate that RAS may have immunological, psychological, genetic and microbiological bases. The purpose of the present study was to investigate the possible association between interleukin-1beta (IL-1beta) +3954 (C/T) genetic polymorphism and RAS in a sample of Brazilian patients.

SUBJECTS AND METHODS

Sixty-two consecutive subjects affected by minor and major forms of RAS and 62 healthy volunteers were genotyped at IL-1beta (+3954). The chi-squared test was used for statistical analysis.

RESULTS

A significant increase in the high production of IL-1beta genotype CT was observed in the group with RAS (P = 0.01). After stratifying RAS patients according to the mean number of lesions per episode, a significant difference was only observed between patients with >or=3 lesions in each episode and control.

CONCLUSION

There is an increased frequency of polymorphism associated with high IL-1beta production in RAS patients.

Interleukin-1β and Serotonin Transporter Gene Polymorphisms in Burning Mouth Syndrome Patients

Burning mouth syndrome (BMS) is a chronic pain syndrome that encompasses all forms of burning sensations in the oral cavity when the oral mucosa is clinically normal. Neural, psychologic, and cytokine factors may be implicated in the pathogenesis of BMS. There are no studies of genetic factors associated with psychologic behavior and cytokine pain sensitivity in BMS patients. The purpose of the present study was to investigate a possible association between functional genetic polymorphisms, +3,954 (C/T) interleukin-1beta, and the polymorphic site on promoter region of the serotonin transporter gene (5-HTTLPR) in a sample of Brazilian patients. Thirty patients affected by BMS and 31 healthy volunteers were genotyped for 5-HTTLPR and IL-1beta gene. The chi-squared test was used for statistical analysis. There was no statistical difference in 5-HTTLPR genotypes between the case and control groups (P = .60), however a significant increase was observed in the IL-1beta high production genotype CT in BMS subjects (P = .005). In conclusion, the present study shows association between BMS and IL-1beta high producer genotype.

PERSPECTIVE

This article shows evidence that genetic polymorphisms associated with IL-1beta high production genotype are implicated on the pathogenesis of BMS. The modulation of IL1beta production may be an interesting tool in BMS management.