Elevated serum IgE in recurrent aphthous stomatitis and associations with disease characteristics

The peripheral immune cell counts and mouth ulcers: A two-sample Mendelian randomization study

Objective

This study explored the causal association of peripheral immune cell counts with mouth ulcers (MUs) by two-sample Mendelian Randomization.

Design

The counts of 12 circulating immune cell types (leukocytes, lymphocytes, monocytes, eosinophils, neutrophils, basophils, CD4+ cells, CD8+ cells, unswitched memory B cells, NK cells, B cells and a derived ratio (CD4+/CD8+)) were determined as the exposure. MUs were the outcome. The analysis was conducted mostly using the inverse-variance weighted (IVW) approach. MR Egger, weighted median, weighted mode and simple mode were used to detect the horizontal pleiotropy.

Results

The IVW results for leukocytes and lymphocyte counts were OR = 0.93, 95 % CI = 0.88-0.98, p = 0.0115 and OR = 0.91, 95 % CI: 0.84-0.98, p = 0.0150, respectively. The Wald ratio result for CD4+ cell and CD8+ cell counts were OR = 0.70, 95 % CI: 0.65-0.75, p = 1.05 × 10-20 and OR = 1.25, 95 % CI: 1.19-1.31, p = 9.99 × 10-21, respectively.

Conclusions

This study supports a causal effect of peripheral immune cell counts on MUs. Higher leukocyte, lymphocyte and CD4+ cell counts can protect against MUs, but higher CD8+ cell counts enhance the risk of MUs. This finding confirms host immune factors play a crucial role in the aetiology of MUs.

Correlating Salivary Levels of Immunoglobin E and Human Eosinophil Cationic Protein in the Aseer Cohort with Recurrent Apthous Stomatitis

Background

Repeated Aphthous Stomatitis (RAS) is the most prevalent inflammatory disorder of the oral mucosa, characterized by recurrent emergence of single or numerous painful ulcers. RAS usually affects healthy people without systemic illnesses. There is evidence linking atopy to the progression of this illness. Immunoglobulin E (IgE) and human eosinophil cationic protein (HECP) levels in the saliva of individuals with aphthous stomatitis were assessed as allergy-related indicators.

Materials and Methods

Sixty people were assessed for this study. 30 patients with RAS were included in the patient group, while 30 healthy individuals made up for the control group. Sixty participants' non-stimulated saliva was taken and IgE and HECP were evaluated using enzyme-linked immunosorbent assay (ELISA). Data were analyzed in SPSS 20 through the Mann-Whitney test and p<0.05 was considered significant.

Results

The salivary level of HECP was significantly (p 0.05) higher among cases (0.83 0.70) compared to controls (0.170 0.15), whereas the salivary level of IgE was not significantly (p = 0.41) higher among cases (35.60 11.19) compared to controls (67.42 18.34).

Conclusion

Even though this study found a positive correlation between elevated HECP levels and RAS, additional research with larger sample sizes is required to identify the biological mechanisms responsible for the observed associations and to include salivary HECP levels in the RAS patient's evaluation.

Integrating GWAS and proteome data to identify novel drug targets for MU

Mouth ulcers have been associated with numerous loci in genome wide association studies (GWAS). Nonetheless, it remains unclear what mechanisms are involved in the pathogenesis of mouth ulcers at these loci, as well as what the most effective ulcer drugs are. Thus, we aimed to screen hub genes responsible for mouth ulcer pathogenesis. We conducted an imputed/in-silico proteome-wide association study to discover candidate genes that impact the development of mouth ulcers and affect the expression and concentration of associated proteins in the bloodstream. The integrative analysis revealed that 35 genes play a significant role in the development of mouth ulcers, both in terms of their protein and transcriptional levels. Following this analysis, the researchers identified 6 key genes, namely BTN3A3, IL12B, BPI, FAM213A, PLXNB2, and IL22RA2, which were related to the onset of mouth ulcers. By combining with multidimensional data, six genes were found to correlate with mouth ulcer pathogenesis, which can be useful for further biological and therapeutic research.

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.

Characterization of immune landscape and development of a novel N7-methylguanine-related gene signature to aid therapy in recurrent aphthous stomatitis

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is the most common inflammatory disease of the oral mucosa resulting in an impaired life quality and even leading to tumors in susceptible populations. N7-Methylguanine (m7G) plays a vital role in various cellular activities but has not yet been investigated in RAS. We aimed at picturing the immune landscape and constructing an m7G-related gene signature, and investigating candidate drugs and gene-disease association to aid therapy for RAS.

METHODS

For our study, m7G-related differentially expressed genes (DEGs) were screened. We outlined the immune microenvironment and studied the correlations between the m7G-related DEGs and immune cells/pathways. We performed functional enrichment analyses and constructed the protein-protein interaction (PPI) and multifactor regulatory network in RAS. The m7G-related hub genes were extracted to formulate the corresponding m7G predictive signature.

RESULTS

We obtained 11 m7G-related DEGs and studied a comprehensive immune infiltration landscape, which indicated several immune markers as possible immunotherapeutic targets. The PPI and multifactor regulatory network was constructed and 4 hub genes (DDX58, IFI27, IFIT5, and PML) were identified, followed by validation of the corresponding m7G predictive signature for RAS. GO and KEGG analyses revealed the participation of JAK-STAT and several immune-related pathways. Finally, we suggested candidate drugs and gene-disease associations for potential RAS medical interventions.

CONCLUSIONS

The present study pictured a comprehensive immune infiltration landscape and suggested that m7G played a vital role in RAS through immune-related pathways. This study provided new insight for the future investigation of the mechanisms and therapeutic strategies for RAS.

Detection of the peripheral blood antigens and clinical value in recurrent aphthous ulcer: A cross-section study

Abstract Background/purpose

Recurrent aphthous ulcer (RAU) is one of the most common diseases of oral mucosa, which is generally believed to be related to immunity, though the etiology is still unclear. It is suspected that allergies are directly related to RAU. So we sought to explore the relationship between hypersensitivity and RAU.

Materials and methods

40 RAU patients who were in ulceration period and 40 people who were in good health were selected from Jan 2016 to Feb 2017, matched in age and sex. The peripheral blood antigens of 40 RAU patients and 40 healthy people was tested, and serum specific IgE (sIgE) with 6 groups of antigens and total IgE (tIgE) analysis was performed to identify IgE-mediated allergic reaction possibly affecting RAU. We then investigated the food intolerance and IgG levels to discover the correlation between non-IgE mediated allergic reaction and RAU.

Results

The positive cases and rate of sIgE in RAU group was higher than that of control, but the difference was not statistically significant (P＞0.05). Positive grade of animal fur scraps (EX1), house dust mixed (HX2) and the serum tIgE concentration of the RAU group were significantly higher than the control group (P＜0.05).The number of food intolerance in RAU group was significantly higher than that in control group (P＜0.05).

Conclusion

Our findings suggested certain correlation between RAU and anaphylaxis. Daily contact allergens and food intolerance may be one of the causes of RAU. Moreover, this provides reference value for clinical diagnosis and treatment.

Relationships of interleukin-17 polymorphisms with recurrent aphthous ulcer risk in a Han Chinese population

Objective

Interleukin (IL)-17 is a multifunctional cytokine with important roles in inflammatory and autoimmune diseases. This case–control study explored the relationships of IL-17A rs2275913 and IL-17F rs763780 single-nucleotide polymorphisms (SNPs) with recurrent aphthous ulcer (RAU) morbidity and severity.

Methods

IL-17A rs2275913 and IL-17F rs763780 SNPs were measured in 125 patients with RAU and 116 healthy control participants. The genotype distributions, disease risks, and relationships with RAU severity were analyzed.

Results

RAU risk was associated with rs2275913 after adjustment for age, body mass index, sex, smoking status, and drinking status (AA vs. GG: odds ratio [OR], 2.759; 95% confidence interval [CI], 1.381–5.512; A allele vs. G allele: OR, 1.783; 95% CI, 1.242–2.560). TC and CC genotypes in rs763780, and the corresponding C allele, demonstrated greater prevalence among patients with RAU, compared with the TT genotype (TC vs. TT, OR: 1.895; 95% CI: 1.088–3.301; CC vs. TT, OR: 4.080, 95% CI: 1.079–15.425; C allele vs. T allele, OR: 1.969, 95% CI: 1.257–3.083). Serum IL-17 concentrations were also higher in patients with RAU than in control participants. These concentrations were associated with IL-17 polymorphisms.

Conclusions

IL-17 polymorphisms might be associated with greater risk of RAU pathogenesis.

Recent advances in the aetiology of recurrent aphthous stomatitis (RAS)

Recurrent aphthous stomatitis (RAS) is the most common disease of oral mucosa, which almost attacks each individual once in their lifespan. Although plenty of factors have been suggested to play a role in the pathogenesis of RAS, the aetiology of RAS is still controversial, which might lead to limited clinical therapies in accordance with each RAS patient. This review mainly illustrates recent advances in potential causes associated with RAS in detail. Deeper comprehension of the aetiology of RAS will support doctors and researchers to make a better management of RAS patients and to discover new treatments. The aetiology of RAS is complicated, hence we should take a comprehensive view into its aetiology, with multiple potential factors being considered. Sample collection of RAS patients have greatly limited the progress in the aetiology of RAS. A research model of multiagency cooperation can help achieve perfect sample collection of year-round and multiposition.

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.

Recurrent Aphthous Stomatitis

Recurrent aphthous stomatitis is a chronic inflammatory disease of the oral mucosa. It is characterized by painful mouth ulcers that cannot be explained by an underlying disease. Recurrent oral mucosal ulcers require a proper differential diagnosis to rule out other possible causes before recurrent aphthous stomatitis is diagnosed. The condition is common, with prevalence rates ranging from 5 to 60% in different series. Its pathogenesis is unknown, but multiple factors are considered to play a part. There are no standardized treatments for this condition and none of the treatments are curative. The goal of any treatment should be to alleviate pain, reduce the duration of ulcers, and prevent recurrence.

Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis

Background

Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis.

Material and Methods

In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant.

Results

The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 Iu/ml and 21.97±6.72 ng/ml in the control group. There was a significant difference between the two groups in terms of salivary levels of IgE and ECP (p=0.001).

Conclusions

The results showed that patients with oral aphthous had higher levels of salivary IgE and ECP than controls. Therefore, measurement of these biomarkers may be useful in the initial evaluation of patients with aphthous stomatitis. Key words:Recurrent aphthous stomatitis, saliva, immunoglobulin E, eosinophil cationic protein.

Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis

Background

Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis.

Material and Methods

In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant.

Results

The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 Iu/ml and 21.97±6.72 ng/ml in the control group. There was a significant difference between the two groups in terms of salivary levels of IgE and ECP (p=0.001).

Conclusions

The results showed that patients with oral aphthous had higher levels of salivary IgE and ECP than controls. Therefore, measurement of these biomarkers may be useful in the initial evaluation of patients with aphthous stomatitis.

Key words:Recurrent aphthous stomatitis, saliva, immunoglobulin E, eosinophil cationic protein.

Recurrent aphthous stomatitis - Etiology, serum autoantibodies, anemia, hematinic deficiencies, and management

Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal diseases characterized by recurrent and painful ulcerations on the movable or nonkeratinized oral mucosae. Clinically, three types of RAS, namely minor, major, and herpetiform types, can be identified. RAS more commonly affects labial mucosa, buccal mucosa, and tongue. Previous studies indicate that RAS is a multifactorial T cell-mediated immune-dysregulated disease. Factors that modify the immunologic responses in RAS include genetic predisposition, viral and bacterial infections, food allergies, vitamin and microelement deficiencies, systemic diseases, hormonal imbalance, mechanical injuries, and stress. Our previous study found the presence of serum gastric parietal cell antibody, thyroglobulin antibody, and thyroid microsomal antibody in 13.0%, 19.4%, and 19.7% of 355 RAS patients, respectively. We also found anemia, serum iron, vitamin B12, and folic acid deficiencies, and hyperhomocysteinemia in 20.9%, 20.1%, 4.8%, 2.6%, and 7.7% of 273 RAS patients, respectively. Therefore, it is very important to examine the complete blood count, serum autoantibody, hematinic, and homocysteine levels in RAS patients before we start to offer treatments for RAS. Because RAS is an immunologically-mediated disease, topical and systemic corticosteroid therapies are the main treatments of choice for RAS.

Recurrent aphthous stomatitis and gene variability in selected interleukins: a case-control study

Genetic factors, especially those related to immune system functioning, have been intensively studied to determine their role in the development of recurrent aphthous stomatitis (RAS). The aim of the present study was to analyze gene variability in interleukin (IL)2, IL4 (and its receptor α, IL4Rα), IL10, and IL13, which were selected based on literature review and/or their functional relevance, in Czech patients with RAS and in healthy controls. In total, 252 subjects (178 controls and 74 patients with RAS) were enrolled in this case-control study, and their detailed anamnestic, clinical, and laboratory data were obtained. Nine polymorphisms in the genes encoding interleukins were determined using PCR techniques. There were no significant differences in allele or genotype frequencies of the IL2, IL4, IL4Rα, IL10, and IL13 polymorphisms rs2069762/rs2069763, rs2243250/rs79071878, rs1801275, rs1800896, and rs1800925, respectively, between controls and patients with RAS. The minority alleles rs1800871 and rs1800872, which encode variants of IL10, were associated with a statistically significantly higher risk of RAS, as confirmed by the results of genotype and haplotype analyses. We suggest that variability in the IL10 gene may play an important role in the development of RAS in the Czech population.

Frequencies of abnormal humoral and cellular immune component levels in peripheral blood of patients with recurrent aphthous ulceration

BACKGROUND/PURPOSE

Recurrent aphthous ulceration (RAU) has an incidence of approximately 20% in general population. However, its exact cause remains unknown. Increasing evidence suggests that immunologic mechanisms may play crucial roles in the etiology of this disease.

MATERIALS AND METHODS

The peripheral blood samples were obtained from 85 patients with RAU during acute phase and 87 healthy controls. The serum levels of IgG, IgA, IgM, C3 and C4 were measured by immunoturbidimetry. In addition, the serum IgE levels were measured by electro-chemiluminescence immunoassay. Furthermore, the percentages of B, T, CD4+ T, CD8+ T lymphocytes and natural killer (NK) cells in peripheral blood were determined by flow cytometry.

RESULTS

Our findings showed that the serum IgG, IgA, IgE, C3 and C4 levels of RAU patients were significantly higher than those of healthy controls. The percentages of CD4+ T cells and B cells in peripheral blood of RAU patients were significantly decreased, whereas the percentages of CD8+ T cells and NK cells of RAU patients were remarkably increased. Our results indicated that the IgG level was elevated in 18 patients (21.2%) and that the IgE level was increased in 21 patients (24.7%). Our results also showed that the frequency of abnormal IgG or IgE levels were significantly correlated with that of abnormal CD8+ T cell percentage in RAU patients.

CONCLUSION

The levels of both humoral and cellular immune components could be altered in RAU. The relationship between humoral and cellular immune may be potentially important immunologic aspects involved in the pathogenesis of RAU.

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.

Immune response of patients with recurrent aphthous stomatitis challenged with a symbiotic

BACKGROUND

There are indications that Th1 polarization of immune response plays an important role in the pathogenesis of recurrent aphthous stomatitis (RAS), and that the use of probiotics can stimulate immune regulatory activity, influencing the course of the disease. The aim of this study was to characterize the initial immune profile of RAS patients and evaluate clinical and serological response following a challenge with symbiotic treatment containing fructooligosaccharide, Lactobacillus, and Bifidobacterium.

METHODS

The immune responses of the 45 patients with RAS, submitted to symbiotic or placebo for 120 days, in relation to 30 RAS-free controls, were evaluated over a period of 6 months. Peripheral blood was collected from all patients at 0 (T0), 120 (T4), and 180 days (T6) after the start of treatment and Th1 (IL12-p70, IFN-γ), Th2 (IL-4), Treg (IL-10), Th17 (IL-17A), inflammatory (TNF-α, IL-6)-associated cytokines, and clinical parameters were quantified.

RESULTS

At T0, significant differences were found in the serological levels of the IFN-γ, IL-4, and IL-6 cytokines of the RAS patients in comparison with the controls. It was observed that the cytokine profile of the RAS group was comprised of 2 distinct clusters: a pure Th2 and a Mixed (Th1/Th2) subtype and that symbiotic treatment induced an improvement in pain and an increase in IFN-γ levels, producing a reduction in Th2 response.

CONCLUSIONS

In RAS, symbiotic treatment based on a fructooligosaccharide, Lactobacillus, and Bifidobacterium composition produced an alteration in the Th2 serological immune profile in the direction of Th1 and improved pain symptomatology.

Resolution of recurrent aphthous ulcers after discontinuation of cow's milk protein intake

BACKGROUND AND OVERVIEW

Authors of published studies have reported elevated levels of circulating antibodies to cow's milk protein (CMP) in patients with recurrent aphthous ulcers (RAUs), and authors of case reports have described resolution of RAU after dairy elimination.

CASE DESCRIPTION

A 10-year-old girl and an 11-year-old boy, both with 5-year histories of frequent RAU episodes, with multiple ulcerations, underwent dairy elimination trials. Both were free of oral ulcers within 2 weeks of discontinuing CMP and remained so with a CMP-free diet. In addition, the first patient had recurrence of ulcerations after occasional ingestion of CMP-containing foods. She showed elevated blood levels of immunoglobulin E in reaction to CMP and soy. Soy intake did not trigger the ulcerations.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The proportion of patients with RAU in whom CMP acts as a trigger is unknown. However, CMP elimination trials are safe and feasible and, therefore, should be considered, particularly before use of medications with potential side effects.

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.