Changes in Th1/Th2-related cytokine expression in the saliva of patients with recurrent aphthous stomatitis before and after prednisone treatment

Evaluation of cytokine expressions in patients with recurrent aphthous stomatitis: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to evaluate the expression levels of various T helper (Th) cell-secreted cytokines in recurrent aphthous stomatitis (RAS). Case-control studies comparing the serum or salivary levels of cytokines between RAS patients and healthy controls were searched in PubMed, EMBASE, Web of Science, and Google Scholar prior to September 30, 2023. Cytokines produced by Th1 (interleukin [IL]-1, IL-2, IL-8, IL-12, tumor necrosis factor alpha [TNF-α], interferon gamma [IFN-γ]), Th2 (IL-4, IL-5, IL-6, IL-10, IL-13), and Th17 (IL-17A) cells were investigated. The standard mean difference (SMD) with 95% confidence interval (CI) was calculated to detect the difference. A total of 20 studies comprising 1070 RAS patients and 536 healthy controls were included. RAS patients had significantly higher salivary levels of IL-2 (SMD = 4.15, 95%CI 0.83-7.48), IL-5 (SMD = 0.53, 95%CI 0.05-1.00), IL-6 (SMD = 0.48, 95%CI 0.12-0.84), IL-12 (SMD = 0.94, 95%CI 0.18-1.71), and TNF-α (SMD = 1.31, 95%CI 0.44-2.18) compared to healthy controls. Serum levels of IL-6 (SMD = 0.48, 95%CI 0.30-0.66), TNF-α (SMD = 0.70, 95%CI 0.22-1.17), and IFN-γ (SMD = 0.72, 95%CI 0.17-1.28) were significantly increased, while serum IL-10 levels (SMD = -2.25, 95%CI -3.99 to -0.52) were reduced in RAS patients. Patients diagnosed with major RAS had markedly elevated serum IL-8 levels (SMD = 0.39, 95%CI 0.07-0.71) and a trend toward higher serum IL-6 levels (SMD = 0.51, 95%CI -0.02 to 1.04) than those with minor RAS. In conclusion, Th1/Th2-related cytokines, especially IL-2, IL-6, and TNF-α, are involved in the pathogenesis of RAS development and progression and are potential therapeutic targets for RAS.

Dynamic salivary cytokine profile of recurrent aphthous stomatitis patients in thalidomide maintenance treatment

OBJECTIVE

To dynamically compare the longitudinal (time axis) and transverse (between groups) differences of the salivary cytokines during thalidomide maintenance treatment of recurrent aphthous stomatitis.

METHODS

A randomized, controlled, clinical trial was performed. After the initial prednisone treatment, thalidomide (50 mg/d vs. 25 mg/d) was used as a maintenance drug for 4 or 8 weeks. The salivary IL-4, 5, 6, 10, TNF-α, and IFN-γ were dynamically detected with a cytometric bead array.

RESULTS

Overall, the level of six elevated salivary cytokines after prednisone treatment was significantly downregulated, remained low during thalidomide maintenance, and rebounded at recurrence. The effect of 50 mg/d thalidomide on the salivary cytokines was not superior to 25 mg/d medication. The relapse-free period following drug withdrawal was the longest in the subgroup using 25 mg/d thalidomide for 8 weeks. The order of magnitude of IL-6 was the most obvious, and at week 8, only the level of IL-6 in the group (25 mg/d thalidomide for 8 weeks) continued to decline compared with the other groups.

CONCLUSION

Thalidomide maintenance treatment can effectively sustain low levels of salivary IL-4, 5, 6, 10, TNF-α, and IFN-γ of recurrent aphthous stomatitis patients. IL-6 displayed a good correlation with the disease and is expected to become an index for diagnosis and follow-up.

CLINICAL RELEVANCE

Low-dose long-term thalidomide maintenance treatment was supported for recurrent aphthous stomatitis.

TRIAL REGISTRATION

Trial registration number of ChiCTR-IPR-16009759 at http://www.chictr.org/index.aspx .

Elevated serum fibrinogen levels in Chinese patients with minor recurrent aphthous stomatitis: An observational study

Fibrinogen is a protein that reflects systemic inflammation and regulates the immune response to disease. However, there is a scarcity of data on fibrinogen in recurrent aphthous stomatitis (RAS). We aimed to test the hypothesis that fibrinogen is involved in the aetiology of RAS. Between November 2016 and November 2018, we included 109 minor RAS patients and 29 age- and sex-matched controls in a single-center, observational study. Their clinical history and ulcer manifestations led to the diagnosis of minor RAS. The ulcer severity score (USS) was used to assess disease severity, and fibrinogen was also collected. We conducted three analyses: Analysis 1 (comparison of fibrinogen levels between patients and controls), Analysis 2 (comparison of fibrinogen levels between high and low USS patients) and Analysis 3 (comparison of fibrinogen levels between before and after anti-inflammatory treatment in patients). The fibrinogen levels in the 109 minor RAS patients were statistically higher than in the 29 controls (mean [SD], 2.6 [0.5] vs. 2.3 [0.3]; Student's t-test, p < 0.001). However, there were no significant differences in fibrinogen levels among the 43 patients with high USS and the 39 patients with low USS (mean [SD], 2.7 [0.5] vs. 2.6 [0.4]; Student's t-test, p = 0.278). Furthermore, fibrinogen levels were significantly higher before anti-inflammatory treatment in comparison to those after anti-inflammatory treatment in the 35 paired patients (mean [SD], 2.6 [0.4] vs. 2.5 [0.4]; Student's t-test, p = 0.026). Interestingly, fibrinogen levels were significantly higher in the 35 paired patients after anti-inflammatory treatment compared to the 29 control subjects (mean [SD], 2.5 [0.4] vs. 2.3 [0.3]; Student's t-test, p = 0.026]. Fibrinogen may play a role in the aetiology of RAS and may be a drug target for RAS treatment. Clinicians should be alert that high serum fibrinogen levels might be associated with the risk of RAS.

Expression of Salivary Ceramide Synthase 1 (CERS1) in Recurrent Aphthous Stomatitis (RAS): A Cross-Sectional Institutional Study

Background The increased rate of apoptosis is one of the major causes of ulcer formation. A variety of factors can influence the rate of apoptosis. Ceramide (CER) is one such factor that has been proposed to play a role in signaling apoptosis induced by extracellular agents. Recurrent aphthous stomatitis (RAS) is a common condition that initially presents in children or adolescents. Multiple recurrent small, round, or ovoid ulcers with erythematous haloes and circumscribed margins are its characteristic features. Its pathogenesis is still a mystery. Ceramide synthase 1 (CERS1) aids in the production of C18 CER. Although the role of CERS1 in aphthous is well understood, its possible intricate role in pathogenesis remains unknown. Aim To evaluate the expression of salivary CERS1 in patients with RAS and healthy individuals. Materials and methods 30 patients were included in the present study. Ethical clearance for this study was obtained, and there were no gender or age limits for enrollment. After obtaining informed consent, 30 salivary samples were collected from patients with RAS (n=15) and from healthy individuals (n=15). Enzyme-linked immunosorbent assay (ELISA) was performed using the CERS1 kit by MyBioSource Inc (San Diego, USA) and the results were recorded. The Chi-square test and Independent t-test were used for statistical analysis with SPSS v23.0 (IBM, Chicago, USA) with a significant p-value of <0.05. Results CERS1 expression was identified in the saliva of all participants. There was a decrease in the salivary CERS1 level in RAS patients (7.6 +/- 2.0 pg/ml) when compared to healthy individuals (8.3 +/- 1.8 pg/ml) but it did not achieve statistical significance. Conclusion We found that salivary CERS1 levels decreased in RAS patients. More research is required to understand CERS1's pathogenetic role.

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.