Association between recurrent aphthous stomatitis and inheritance of a single‐nucleotide polymorphism of the NOS2 gene encoding inducible nitric oxide synthase

J Oral Pathol Med (2011) 40 : 715–720 Background: Recurrent aphthous stomatitis is a common ulcerative disease of the oral mucosa. Recurrent oral aphthous ulceration is also a feature of the more serious and systemic Behçet’s disease. Nitric oxide is a free radical synthesized by one of a family of nitric oxide synthase (NOS) enzymes and is an important regulator of inflammation and immunity. Association of NOS3 gene polymorphisms encoding endothelial nitric oxide synthase has been reported in Behçet’s disease but not recurrent aphthous stomatitis. The aim of this study was to investigate any association between NOS2 gene polymorphisms that encode inducible nitric oxide synthase and recurrent aphthous stomatitis. Methods: This is a case control association study. Eighty‐three Jordanian recurrent aphthous stomatitis patients and 83 age, gender and ethnically matched controls were genotyped for three NOS2 single‐nucleotide polymorphisms, rs10459953, rs1060822 and rs2297518. Chi‐squared analysis was used to compare the allele frequencies and genotypes. Results: There was a significant association between recurrent aphthous stomatitis and inheritance of single‐nucleotide polymorphism rs2297518 (P = 0.006). Although no direct association was demonstrated between rs10459953 or rs1060822 and recurrent aphthous stomatitis, a strong linkage disequilibrium was identified between rs1060822 and rs2297518. Conclusion: Inheritence of a NOS2 single‐nucleotide polymorphism rs2297518 is associated with increased risk of recurrent aphthous stomatitis in a Jordanian population. Confirmatory studies in other populations and investigation of other NOS2 gene polymorphisms will enhance our understanding of the functional basis of this association and help elucidate the role of inducible nitric oxide synthase in recurrent aphthous stomatitis.     

Interleukin-6 gene polymorphism in Saudi population with recurrent aphthous stomatitis

IntroductionRecurrent aphthous ulcers are common but poorly understood mucosal disorder. Local and systemic conditions, genetic, immunological, and microbial factors may play a role in the pathogenesis of recurrent aphthous ulceration (RAS). Different aetiologies and mechanisms might be involved in the aetiopathogenesis of aphthous ulceration. Cytokines are thought to play an important role and high levels of interleukin (IL)-6, a pro-inflammatory cytokine, have been detected in the circulation of ulcer tissue. The purpose of the present study was to investigate if polymorphisms of IL-6 gene are associated with RAS in a cohort of specific population.MethodologyA total of 37 RAS patients and 18 healthy controls were included in the study. The genotypes of IL-6 gene −174G\C polymorphisms were determined using polymerase chain reaction and sequencing.ResultsFour SNPs were analyzed, one known mutation which been evaluated as a risk factor for RAS, and three new mutations were investigated. The genotype frequencies of −174G\C polymorphism showed no statistically significant differences between RAS patients and controls (p\ 0.629). Polymorphisms of Rs1800795 heterozygous genotype were found in 21.62% of cases, and 33.33% of controls. Homozygous mutant genotype was found in 5.41% of cases and no homozygous mutant genotype was found in control group. The normal alleles were found in 72.97% of cases and 66.67% of control.ConclusionThus, according to our study, IL-6 gene polymorphism is not involved in RAS pathogenesis. Further studies should be done on large sample size to detect any association with pathogenesis. However, an alternative reasoning could point out to a complex interactive effect on IL-6 expression that might exist between any of the detected polymorphisms.     

Lack of association between Streptococcus oralis and recurrent aphthous stomatitis

In the present study, the potential involvement of Streptococcus oralis in the aetiology of recurrent aphthous stomatitis (RAS) was investigated using the polymerase chain reaction (PCR). Biopsies from 28 RAS patients were analysed, in addition to 20 oral lichen planus (OLP) and 13 normal biopsies that were used as controls. PCR was carried out using a primer pair that targets the D-alanine:D-alanine ligase gene and detects DNA from both S. oralis and the closely related species Streptococcus mitis. Discrimination between these two species was achieved by digestion of PCR products with the restriction endonucleases HaeIII and HindIII, which both give distinct restriction profiles for each species. S. oralis DNA was detected in 8 of 28 (29%) RAS samples, 10 of 20 (50%) OLP samples and 6 of 13 (46%) normal samples. These results suggest that S. oralis is not of primary aetiological significance in RAS.     

The recurrent aphthous stomatitis frequency in the smoking cessation people

This study was aimed to evaluate the frequency of recurrent aphthous stomatitis (RAS) within the 6-week period after quitting smoking. The study group consisted of 90 subjects. Oral, medical findings and tobacco habits were recorded for all subjects. Nicotine replacement therapy (NRT) and behavioral treatment were applied to some of the subjects by a family physician. All subjects were evaluated for their RAS and periodontal measurements on baseline, 1, 3, 6 weeks by a periodontist. While the subjects were in this smoking cessation programme, 64 of the 90 smokers successfully quit smoking within the 6 weeks and 26 smokers dropped out during the third week of the study. Point prevalence of RAS among the subjects on the first day of the quitting period and at the end of the first, third and sixth week after smoking cessation was 3.3% (3/90), 18.9% (17/90), 21.1% (19/90) and 17.1 (11/64), respectively. In the following weeks, aphthous ulcer point prevalence was significantly higher than the quitting level (p < 0.05). As the time after quitting increased, the incidence of aphthous ulcer decreased. Of 64 patients, 35 (54.6%) completed the 6 weeks using NRT and 29 (45.4%) of them did not use any medication. The aphthous ulcer frequency observed in the patients taking NRT [11.4% (4/35)] was lower when compared with the subjects taking no NRT [24.1% (7/29)] (p > 0.05). The results of this study confirm that RAS is a complication of quitting smoking. Further studies are needed to identify the effects of NRT on RAS.     

The effect of bee propolis on recurrent aphthous stomatitis: a pilot study

Recurrent aphthous stomatitis (RAS) is a common, painful, and ulcerative disorder of the oral cavity of unknown etiology. No cure exists and medications aim to reduce pain associated with ulcers through topical applications or reduce outbreak frequency with systemic medications, many having serious side effects. The purpose of this pilot study was to evaluate the potential of a product to reduce the number of outbreaks of RAS ulcers. Propolis is a bee product used in some cultures as treatment for mouth ulcers. In this randomized, double-blind, placebo-controlled study, patients were assigned to take 500 mg of propolis or a placebo capsule daily. Subjects reported a baseline ulcer frequency and were contacted biweekly to record recurrences. Data were analyzed to determine if subjects had a decrease of 50% in outbreak frequency. The data indicated a statistically significant reduction of outbreaks in the propolis group (Fisher’s exact test, one sided, p = 0.04). Patients in the propolis group also self-reported a significant improvement in their quality of life (p = 0.03). This study has shown propolis to be effective in decreasing the number of recurrences and improve the quality of life in patients who suffer from RAS. Propolis should be evaluated further in a larger sample clinical trial.     

Association of interleukin-1beta 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.     

Salivary cortisol and anxiety in recurrent aphthous stomatitis

Anxiety and salivary cortiso) were measured in two groups of patients with recurrent aphthous ulceration. One group of patients had persistent aphthae (Group 1) and the others had been relieved of their aphthae following correction of delected haematinic deficiency states (Group 2). Anxiety was measured using the Hospital Anxiety and Depression scale and radioimmunoassay of salivary cortisol. There was a statistically significant increased proportion of borderline or clinically anxious patients in Group 1 compared to Group 2 ( P <0.05). Median salivary' cortisol levels also showed a statistically significant elevation in Group 1 (P<0.0 1). It is concluded that stress may play a role in the aetiology of recurrent aphthous stomatitis, particularly in patients who have an underlying anxiety trait.     

Helicobacter pylori DNA in recurrent aphthous stomatitis

BACKGROUND: Considering not only the fact that recurrent aphthous stomatitis (RAS) and stomach ulcers are immunologically mediated ulcers associated with Helicobacter pylori, but also the recent evidence that anaemia can be associated with both diseases, and the discovery of H. pylori in the oral mucosa led us to hypothesize that this bacteria may be related to RAS pathogenesis. METHODS: Thirty-six consecutive subjects affected by minor and major forms of RAS and 48 healthy volunteers were included in the present study. The nested polymerase chain reaction (PCR) technique was used to detect the presence of H. pylori in the oral lesion, the normal contralateral mucosa of patients affected by RAS and the oral mucosa of control subjects. The chi2- and Fisher's tests were used for statistical analysis. RESULTS: No association between RAS lesions and H. pylori was observed. However, 14 out of 36 (38.9%) of the patients with RAS were found to show the presence of H. pylori DNA in the lesion and/or contralateral mucosa. Sixteen out of 48 (33.3%) of the patients without RAS (control subjects) were positive (P > 0.05). CONCLUSION: The present study does not give support to the assumption that H. pylori could be involved in RAS development.     

Effect of Zendium toothpaste on recurrent aphthous stomatitis

Abstract – A Double-blind clinical trial with cross-over was conducted for a period of 12 months in 25 patients with recurrent aphthous stomatitis (RAS). The effect of the amyloglucosidase and glucoseoxidase containing Zendium toothpaste on the discomfort, number of exacerbations, duration of exacerbation, number of ulcers and number of days with pain caused by RAS was studied. The use of Zendium significantly reduced the sensation of discomfort from RAS as compared to the use of placebo toothpaste (0.025>p>0.01). However, the patients were unable to discriminate significantly between Zendium and placebo when asked to choose one of the toothpastes (0.10>p>0.05) and no significant differences were demonstrated as far as the above mentioned parameters of disease serverity were concerned. Therefore, it is concluded that the reducing effect of Zendium containing amyloglucosidase and glucoseoxidase on RAS is weak as compared to a similar toothpaste without these enzymes.     

Helicobacter pylori and gastric hyperacidity,and their association with recurrent aphthous stomatitis

Helicobacter pylori is an established cause of gastric ulcers. Its role in causing recurrent aphthous stomatitis (RAS) remains controversial. Fifty-two RAS patients and 52 sex-matched controls were recruited in this case–control study. All subjects were screened for hematinic deficiencies and H. pylori. The latter was assessed quantitatively using the ¹⁴C-urea breath test. The χ² test and Wilcoxon signed ranks test were used to compare H. pylori and hematinic indices between cases and controls, while conditional logistic regression was used to assess the associations between the occurrence of RAS and independent factors. H. pylori was positive in 56.7% of the overall sample, with no difference between RAS patients (50.8%) and controls (49.2%) (P = 0.843). The median H. pylori and haematological indices values did not show any association with ulcer diameter, number, or frequency. Interestingly, gastric hyperacidity was significantly associated with RAS, and this association was independent from tobacco smoking, alcohol drinking, and H. pylori (odds ratio 14.99, 95% confidence interval 2.47–90.95; P = 0.003). This study found no association between H. pylori and RAS. The association between RAS and gastric hyperacidity suggests that gastric refluxate, not H. pylori, has an effect on the oral mucosa that favours an ulcerative change.     

Topical minocycline for managing symptoms of recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is a common ulcerative condition of the oral mucosa. In this study, minocycline oral rinses were compared to a placebo in patients suffering from frequent episodes of RAS. Thirty‐three patients with RAS were randomly allocated to topical therapy with 0.2% minocycline or a placebo aqueous solution mouthwash. Seven patients also participated in a blind crossover study. The intensity of pain was recorded daily using a visual analogue scale. Minocycline mouthwashes resulted in significant reduction in the severity and duration of pain due to RAS. The findings in the subgroup that participated in the crossover were consistent with outcomes in the randomized study. The findings of this study show that minocycline oral rinses reduce pain in patients with RAS and may have implications for the use of minocycline in other non‐infectious inflammatory ulcerative oral mucosal diseases.     

Polymorphonuclear neutrophil function in recurrent aphthous stomatitis

Polymorphonuclear neutrophils (PMN) are the predominant cell type in the established lesion of recurrent aphthous stomatitis (RAS). The function of these cells was studied in 15 patients with RAS and 15 age and sex matched controls. Production of oxygen radicals was assessed using cytochrome-c and nitroblue tetrazolium dye (NBT) reduction assays. Oxidative metabolism was found to be similar for experimental and control groups in both stimulated and non-stimulated assays. Adherence to glass surfaces by PMN was also measured. Adherence of PMN, both from patients and controls, was significantly reduced by serum, but to a lesser extent by serum from patients compared to controls. This effect of serum on adherence was reversed by phorbol myristate acetate (PMA) stimulation. These studies suggest that increased adherence of stimulated PMN, due to humoral factors, may be involved in perpetuating ulcerative lesions in RAS.     

Recurrent aphthous stomatitis: a review

J Oral Pathol Med (2012) 41: 577-583 Recurrent aphthous stomatitis (RAS) is a common clinical condition producing painful ulcerations in oral cavity. The diagnosis of RAS is based on well-defined clinical characteristics but the precise etiology and pathogenesis of RAS remain unclear. The present article provides a detailed review of the current concepts and knowledge of the etiology, pathogenesis, and management of RAS.     

Urban legends: recurrent aphthous stomatitis

Oral Diseases (2011) 17 , 755–770 Recurrent aphthous stomatitis (RAS) is the most common idiopathic intraoral ulcerative disease in the USA. Aphthae typically occur in apparently healthy individuals, although an association with certain systemic diseases has been reported. Despite the unclear etiopathogenesis, new drug trials are continuously conducted in an attempt to reduce pain and dysfunction. We investigated four controversial topics: (1) Is complex aphthosis a mild form of Behçet’s disease (BD)? (2) Is periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome a distinct medical entity? (3) Is RAS associated with other systemic diseases [e.g., celiac disease (CD) and B12 deficiency]? (4) Are there any new RAS treatments? Results from extensive literature searches, including a systematic review of RAS trials, suggested the following: (1) Complex aphthosis is not a mild form of BD in North America or Western Europe; (2) Diagnostic criteria for PFAPA have low specificity and the characteristics of the oral ulcers warrant further studies; (3) Oral ulcers may be associated with CD; however, these ulcers may not be RAS; RAS is rarely associated with B12 deficiency; nevertheless, B12 treatment may be beneficial, via mechanisms that warrant further study; (4) Thirty‐three controlled trials published in the past 6 years reported some effectiveness, although potential for bias was high.     

Increased odds ratio for COVID‐19 in patients with recurrent aphthous stomatitis

The ACE2 receptor, the binding sites for the COVID‐19, is expressed abundantly in the oral cavity, raising the question of whether the mouth is a target for the virus in addition to organs such as kidneys and lungs. Recently, a flurry of individual case reports on oral manifestation of COVID‐19 including ulceration, blistering lesions, and stomatitis were published. However, it is not clear whether the oral presentations that are not unique to the virus are indeed related to the virus and appear at a higher prevalence than in the general population. We used the i2b2 platform of hospital patient's registry to determine the odds ratio for COVID‐19 in patients that were diagnosed with recurrent aphthous stomatitis, an entity restricted to the oral cavity. The overall odds ratio for COVID‐19 in patients with recurrent aphthous stomatitis before adjustments was 14 and after adjustment for gender, race, and age was 13.9, 6.5, and 2.93, respectively. The odds ratio remained increased after adjustments of the comorbidities such as respiratory disease, endocrine disease, obesity, diabetes, circulatory disease, and smoking and was 3.66, 7.46, 4.6, 10.54, 7.37, and 7.52, respectively. When adjusted for recurrent aphthous stomatitis, the respiratory disease had an odd ratio of 8.56 to be associated with COVID‐19. African American race and age‐group 18‐34 were additional significant risk factors. The present study has demonstrated a significant association between COVID‐19 and RAS; however, additional longitudinal and laboratory studies are necessary to establish a cause and effect relationship between these 2 conditions.