Oral lichen planus: focus on etiopathogenesis

Role of Oral Microbiota Dysbiosis in the Development and Progression of Oral Lichen Planus

Oral lichen planus (OLP) is a chronic inflammatory autoimmune disease of the oral cavity with malignant potential affecting 1.01% of the worldwide population. The clinical patterns of this oral disorder, characterized by relapses and remissions of the lesions, appear on buccal, lingual, gingival, and labial mucosa causing a significant reduction in the quality of life. Currently, there are no specific treatments for this disease, and the available therapies with topical and systemic corticosteroids only reduce symptoms. Although the etiopathogenesis of this pathological condition has not been completely understood yet, several exogenous and endogenous risk factors have been proposed over the years. The present review article summarized the underlying mechanisms of action involved in the onset of OLP and the most well-known triggering factors. According to the current data, oral microbiota dysbiosis could represent a potential diagnostic biomarker for OLP. However, further studies should be undertaken to validate their use in clinical practice, as well as to provide a better understanding of mechanisms of action and develop novel effective intervention strategies against OLP.

Integrative Approaches for the Diagnosis and Management of Erosive Oral Lichen Planus

Erosive oral lichen planus (EOLP) represents a significant challenge in dental and medical management due to its chronic inflammatory nature, painful symptoms, and impact on quality of life. This study aims to evaluate the current diagnostic approach with novel non-invasive techniques, such as dermoscopy, and also the landscape of treatment options for EOLP, focusing on its efficacy, safety, and the challenges that it present in clinical practice. Through a comprehensive literature review, we explored the use of topical corticosteroids, systemic immunosuppressants, biologics, and Janus kinase (JAK) inhibitors in treating EOLP, alongside examining patient compliance, psychological impacts, and the risk of adverse effects and recurrence. Our findings reveal that while topical corticosteroids are the cornerstone of EOLP treatment, offering symptomatic relief, their long-term use is limited by side effects and tolerance development. Systemic therapies and biologics provide alternatives for refractory cases but necessitate careful adverse effect monitoring. JAK inhibitors show promise as an innovative treatment avenue but require more evidence on long-term safety and efficacy. This study highlights the necessity of personalized treatment approaches due to the variable disease course and response to treatment, underscoring the importance of a multidisciplinary strategy in managing EOLP. The complexity of EOLP treatment, compounded by its psychological and quality of life impacts, demands ongoing research into targeted therapies, the establishment of standardized treatment protocols, and the development of effective outcome measures to improve patient care and treatment outcomes.

Evaluation of the association between TNF-α-1031 T/C polymorphism with oral lichen planus disease

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated autoimmune disease that affects the epithelial cells of the oral cavity. This study was performed to investigate any possible relationship between - 1031(T/C) polymorphism (rs1799964) of the tumor necrosis factor α (TNF-α) gene with the risk and severity of oral lichen planus (OLP) disease among an Iranian population.

METHOD

Saliva samples were collected from 100 patients with OLP and a similar number of healthy controls (age and sex-matched). Then, DNA was extracted from the collected samples for genotyping TNF-α-1031 T/C polymorphism using the PCR-CTPP method. The results were assessed using SPSS software.

RESULTS

The findings revealed a significantly higher prevalence of the C allele in OLP patients (53%) compared to healthy controls (36%), suggesting an association between TNF-alpha gene polymorphism and OLP. A multivariate logistic regression analysis supported this finding, as the presence of the C allele was significantly associated with an increased risk of OLP [χ2 = 4.17, p = 0.04, 95% CI = 1.01-2.65, OR = 1.64]. However, our data indicated no significant association between TNF-alpha-1031 T/C gene polymorphism and OLP severity.

CONCLUSIONS

These findings provide the first evidence supporting a possible role of TNF-α-1031 T/C gene polymorphism in OLP susceptibility in the Iranian population. The findings of this study demonstrate a positive association between TNF-α-1031 C/T allele distribution and the risk of OLP disease in the Iranian population. Therefore, carrying the C allele may increase the susceptibility to OLP disease.

Crossroads between Skin and Endocrine Glands: The Interplay of Lichen Planus with Thyroid Anomalies

In this narrative review, we aimed to overview the interplay between lichen planus (LP) and thyroid conditions (TCs) from a dual perspective (dermatologic and endocrine), since a current gap in understanding LP-TC connections is found so far and the topic is still a matter of debate. We searched PubMed from Inception to October 2023 by using the key terms "lichen planus" and "thyroid", (alternatively, "endocrine" or "hormone"). We included original clinical studies in humans according to three sections: LP and TC in terms of dysfunction, autoimmunity, and neoplasia. Six studies confirmed an association between the thyroid dysfunction (exclusively hypothyroidism) and LP/OL (oral LP); of note, only one study addressed cutaneous LP. The sample size of LP/OLP groups varied from 12-14 to 1500 individuals. Hypothyroidism prevalence in OLP was of 30-50%. A higher rate of levothyroxine replacement was identified among OLP patients, at 10% versus 2.5% in controls. The highest OR (odd ratio) of treated hypothyroidism amid OLP was of 2.99 (p < 0.005). Hypothyroidism was confirmed to be associated with a milder OLP phenotype in two studies. A single cohort revealed a similar prevalence of hypothyroidism in LP versus non-LP. Non-confirmatory studies (only on OLP, not cutaneous LP) included five cohorts: a similar prevalence of hypothyroidism among OLP versus controls, and a single cohort showed that the subjects with OLP actually had a lower prevalence of hypothyroidism versus controls (1% versus 4%). Positive autoimmunity in LP/OLP was confirmed in eight studies; the size of the cohorts varied, for instance, with 619 persons with LP and with 76, 92, 105, 108, 192, 247, and 585 patients (a total of 1405) with OLP, respectively; notably, the largest control group was of 10,441 individuals. Four clusters of approaches with respect to the autoimmunity in LP/OLP were found: an analysis of HT/ATD (Hashimoto's thyroiditis/autoimmune thyroid diseases) prevalence; considerations over the specific antibody levels; sex-related features since females are more prone to autoimmunity; and associations (if any) with the clinical aspects of LP/OLP. HT prevalence in OLP versus controls was statistically significantly higher, as follows: 19% versus 5%; 12% versus 6%; and 20% versus 9.8%. A single study addressing LP found a 12% rate of ATDs. One study did not confirm a correlation between OLP-associated clinical elements (and OLP severity) and antibody values against the thyroid, and another showed that positive TPOAb (anti-thyroperoxidase antibodies) was more often found in erosive than non-erosive OLP (68% versus 33%). Just the reverse, one cohort found that OLP subjects had a statistically significantly lower rate of positive TPOAb versus controls (9% versus 15%). Five case-control studies addressed the issue of levothyroxine replacement for prior hypothyroidism in patients that were diagnosed with OLP (no study on LP was identified); three of them confirmed a higher rate of this treatment in OLP (at 8.9%, 9.7%, and 10.6%) versus controls. In conclusion, with regard to LP/OLP-TC, we note several main aspects as practical points for multidisciplinary practitioners: OLP rather than LP requires thyroid awareness; when it comes to the type of thyroid dysfunction, mostly, hypothyroidism should be expected; female patients are more prone to be associated with ATDs; a potential higher ratio of OLP subjects taking levothyroxine was found, thus a good collaboration with an endocrinology team is mandatory; and so far, OLP individuals have not been confirmed to be associated with a higher risk of thyroid nodules/cancer.

Systemic non-steroidal immunomodulators for oral lichen planus treatment-a scoping review

OBJECTIVE

The aim of this scoping review was to evaluate the efficacy and safety of the use of systemic nonsteroidal immunomodulators (SNSI) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

This review was conducted according to PRISMA-ScR guidelines and registered at PROSPERO (CRD42021243524). Consulted databases were Pubmed, Embase, Scopus, and Web of Science. The inclusion criteria was as follows: clinical trials, case series, prospective, and retrospective studies conducted with participants presenting OLP of any sex and age.

RESULTS

Thirty-two studies were selected, assessing 9 different SNSI: methotrexate, dapsone, levamisole, hydroxychloroquine, thalidomide, metronidazole, azathioprine, mycophenolate mofetil, and colchicine. Methotrexate and dapsone were the drugs with the best evidence among the options included, regarding number and quality of studies. Methotrexate resulted in significant improvement in the clinical condition and remission of symptoms, ranging between 63 and 93% of cases. Dapsone presented a similar effect to the use of topical corticosteroids and tacrolimus CONCLUSION: Among SNSI therapeutic options, methotrexate, and dapsone showed promising efficacy and safety. However, large-scale randomized clinical trials are still needed.

CLINICAL RELEVANCE

SNSI have been used in the treatment of recalcitrant OLP; however, so far, it is not clear which are the best options. This scoping review highlights the potential use of methotrexate and dapsone.

Analysis of oral lichen planus severity on micro-RNA linked with malignant transformation risks

OBJECTIVE

The present study evaluated the oral tissue expression of micro-RNA (miRNAs) linked to the potential malignant evolution of oral lichen planus (OLP). Furthermore, the correlation between OLP severity and miRNAs expression was assessed, and possible predictors of miRNAs in OLP patients were identified.

METHODS

The present study enrolled 41 patients with OLP (median age 58 years) and 42 healthy controls (median age 59 years). In each patient, miRNA levels (miR-7a-3p,-7a2-3p,-7a-5p,-21-3p,-21-5p,-100-3p,-100-5p,-125b-2-3p,-125b-5p,-200b-3p,-200b-5p) were assessed and analyzed through reverse transcription polymerase chain reaction. Clinical parameters and the eventual presence of OLP symptoms, signs, and disease severity scores in each patient were reported using an anamnestic questionnaire.

RESULTS

In comparison with healthy controls, OLP patients showed significantly higher miR-7a-3p,-7a-2-3p,-21-3p, miR-21-5p and miR-100-5p levels (p < 0.05) and significantly lower miR-125b-2-3p,-125b-5p,-200b-3p, and -200b-5p levels (p < 0.05). Furthermore, OLP symptoms and signs and disease severity scores were significantly correlated and were also predictors of all analyzed miRNAs (p < 0.05).

CONCLUSIONS

In comparison with healthy subjects, OLP patients exhibited unbalanced oral miRNAs expression linked to the risk of potential malignant evolution of OLP. Furthermore, some miRNAs were correlated with OLP extent and were significant predictors of OLP symptoms, signs, and disease severity scores.

Upregulation of IL-37 in epithelial cells: A potential new mechanism of T cell inhibition induced by tacrolimus

Oral lichen planus (OLP) is a chronic T cell-mediated mucocutaneous disease characterized by T cell infiltration at the connective tissue-epithelium interface. Traditionally, topical corticosteroids are used as the first-line drugs to treat OLP. However, long-term use of corticosteroids may lead to drug tolerance, secondary candidiasis, and autoimmune adrenal insufficiency. Although topical tacrolimus has often been recommended for short-term use in corticosteroid-refractory OLP, the precise role of tacrolimus in epithelial cells remains elusive. This study showed that tacrolimus could directly upregulate the expression of IL-37 in human gingival epithelial cells by promoting the TGF-βRI/Smad3 pathway independently of calcineurin inhibition and MAPKs. In contrast, dexamethasone, one of the corticosteroids, did not have the same effect. Moreover, IL-37 could inhibit the proliferation of activated T cells and the secretion of effector cytokines and alleviate epithelial cell apoptosis and death caused by activated T cells ina co-culturesystem. Furthermore, compared with healthy controls, IL-37 and p-Smad3 levels significantly increased in the oral mucosa affected by OLP, especially in the epithelium. IL-37 might have mediated a negative feedback mechanism to curb excessive inflammation in OLP. However, the expression of IL-37 was not associated with the infiltration of CD8+ T cells and Tregs in OLP, implying that IL-37 might mostly affect T cell activation rather than T cell differentiation and migration. Overall, this study discovered a potential novel mechanism by which tacrolimus might indirectly inhibit T cell-mediated immune damage by upregulating IL-37 in human gingival epithelial cells.

Evaluation of the salivary level of glutathione reductase, catalase and free thiol in patients with oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is a usual chronic inflammatory disease of the oral mucosa with malignant capacity, whose pathogenesis is not yet well known. Free radicals and reactive oxygen species may have a vital role in the pathogenesis of oral lichen planus. This study aimed to assess Glutathione reductase, catalase, and free thiol levels in the saliva of OLP patients and compare it with healthy people.

METHODS

In this cross-sectional study, 35 patients with OLP and 20 healthy people were involved. Five mL of whole, unstimulated saliva samples were collected in the morning, and the salivary levels of antioxidants were measured by ELISA technique. In this experiment, sex, age and OLP types were also evaluated.

RESULTS

There was a significant decrease in the patients' salivary level of Glutathione reductase (0.2043 mU/ml in patients and 0.3901 mU/ml in the control group) and catalase (0.1525 mU/ml in patients and 0.2700 mU/ml in the control group) (p = 0.001). But there were no differences between the two groups regarding free-thiol levels (0.0586 mU/ml in patients and 0.0569 mU/ml in the control group) (p = 0.7). However, there was no correlation between age and gender with the antioxidants' contents. There was a significant decrease in glutathione reductase and catalase in the erosive type than in the non-erosive type.

CONCLUSIONS

In this study, we found that the salivary levels of Glutathione reductase and Catalase were lower in OLP patients than in the healthy group, which means these antioxidants were affected by OLP and also associated with the type of it. So salivary Glutathione reductase and Catalase levels may be used as biomarkers for OLP monitoring and treatment.

The correlation between human papillomavirus and oral lichen planus: A systematic review of the literature

INTRODUCTION

Oral lichen planus (OLP) is a chronic inflammatory disorder with cell-induced immunopathological responses and is considered a potential malignancy disorder in the oral cavity. Due to the high prevalence of OLP as well as the potential for malignancy, human papillomaviruses (HPVs) may play an important role in it. Although previous studies have explored the possible relationship between HPV and OLP, the findings have been conflicting and nonconclusive. This study aims to review the studies that investigated HPV-16 and HPV-18 in OLP.

METHODS AND MATERIALS

The research protocol followed the Preferred Reporting Items for Systematic Reviews (PRISMA2020) checklist. The online databases Pubmed, Scopus, Embase, Google Scholar, and Cochrane were searched using the following individual keywords: "OLP" OR "Oral Lichen Planus" OR "HPV" OR "Human Papillomavirus." The search strategy resulted in the selection of 80 articles. The articles were evaluated, and after duplication removal, 53 abstracts were reviewed, resulting in the selection of 25 studies according to inclusion and exclusion criteria. The risk of bias assessment was done by using the Modified Newcastle-Ottawa quality assessment scale. The overall prevalence of HPV in OLP lesions varied from 2.7% to 70%, depending on the type of diagnostic method used.

CONCLUSION

Despite the studies conducted on the relationship between OLP and HPV infection, there is still no conclusive evidence that HPV can play a role in the etiopathogenesis of OLP, either in clinical manifestations or in the malignant transformation of lesions.

The potential roles of Th17 cells in the pathogenesis of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated chronic autoimmune disease, whose pathogenesis and etiology are not entirely understood. OLP is characterized by subepithelial lymphocyte infiltration and elevated intra-epithelial lymphocytes. The majority of lamina propria lymphocytes are CD4⁺ T cells. CD4⁺ helper T (Th) cells play a crucial role in activating CD8⁺ cytotoxic T cells (CTLs) through interactions and cytokine production. Th1 and Th2 cells are well-accepted to be associated with OLP pathogenesis. However, OLP treatment is challenging yet, the more information we have about the pathology of OLP, the easier it will be treated. With the discovery of Th17 cells in recent years and the demonstration of their role in autoimmune disease, many researchers started to investigate the role of Th17 in the pathogenesis of OLP.

METHODS

To make up this review, studies covering the role of TH17 in different types of lichen planus were selected from major databases.

RESULTS

As we review in this article, Th17 cells and their signature cytokines play an important role in OLP pathogenesis. As well, utilizing some anti-IL-17 antibodies showed promising results in improving the disease; however, more studies are still needed to better understand and treat OLP.

Cathepsins in oral diseases: mechanisms and therapeutic implications

Cathepsins are a type of lysosomal globulin hydrolase and are crucial for many physiological processes, including the resorption of bone matrix, innate immunity, apoptosis, proliferation, metastasis, autophagy, and angiogenesis. Findings regarding their functions in human physiological processes and disorders have drawn extensive attention. In this review, we will focus on the relationship between cathepsins and oral diseases. We highlight the structural and functional properties of cathepsins related to oral diseases, as well as the regulatory mechanisms in tissue and cells and their therapeutic uses. Elucidating the associated mechanism between cathepsins and oral diseases is thought to be a promising strategy for the treatment of oral diseases and may be a starting point for further studies at the molecular level.

Analysis of the response to two pharmacological protocols in patients with oral lichen planus: A randomized clinical trial

OBJECTIVE

To evaluate the effectiveness of two different therapies on oral lichen planus (OLP) treatment through the analysis of OLP symptoms and signs and to analyze the risk of side effects related to the adopted protocols.

METHODS

Thirty-eight patients with OLP were selected according to van der Meij and van der Waal clinical and histopathological criteria. Through a randomized design, 19 patients received Tacrolimus 0.1% ointment (T group) and 19 an anti-inflammatory mouthwash (M group) composed of calcium hydroxide 10%, hyaluronic acid 0.3%, umbelliferone, and oligomeric proanthocyanidins. The patients were examined on a regular basis for OLP symptoms, signs, and disease severity score changes over a 3-month follow-up period.

RESULTS

Both treatments were effective in the reduction of OLP signs and symptoms. However, at 3 months (T3), in comparison with the M group, T group patients showed significantly lower mean values of OLP signs (p = 0.035), symptoms (p = 0.045), and disease severity scores (p = 0.041). Moreover, the Spearman test showed that there was a significant correlation between OLP signs and symptoms at each follow-up session in all patients.

CONCLUSIONS

Both treatments demonstrated a significant approach to control OLP. However, tacrolimus determined a more effective improvement in OLP signs and symptoms compared to anti-inflammatory mouthwash at 3-month follow-up.

Updates on immunological mechanistic insights and targeting of the oral lichen planus microenvironment

Oral lichen planus (OLP) is a chronic immune inflammatory disease that is an oral potentially malignant disorder (OPMD), occurs in the oral mucosa and affects approximately 0.5% to 4% of the general population. There are usually five types of OLP: reticular/papular, plaque-like, atrophic/erythematous, erosive/ulcerative, and bullous. Furthermore, the chance of causing oral squamous cell carcinoma (OSCC) is 1.4%. Although the etiology of OLP is still unknown, accumulating evidence supports that immune dysregulation may play a vital role in the pathogenesis of OLP, especially the massive production of various inflammatory cells and inflammatory mediators. In this review, we focus on the relationship between OLP and its immune microenvironment. We summarize current developments in the immunology of OLP, summarizing functional cell types and crucial cytokines in the OLP immune microenvironment and the underlying mechanisms of key signaling pathways in the OLP immune microenvironment. We highlight the application potential of targeted immune microenvironment therapy for OLP.

Oral immune-mediated disorders with malignant potential/association: An overview

A group of oral disorders or conditions, which may result from, or could be triggered by an abnormality in the normal immune response of an individual are known as oral immune-mediated disorders. Some of these disorders have malignant potential, while others are associated with malignancy. In this overview, we will discuss a few of the oral diseases (such as oral lichen planus, primary Sjogren's syndrome, systemic lupus erythematosus, dermatitis herpetiformis, and linear immunoglobulin A bullous dermatosis, to name a few), which are caused due to irregularity in the immune system and are either associated with malignancy or capable of undergoing malignant transforming, thereby increasing the morbidity and mortality rate.

Lymphocyte and CD62E expression in lichen planus and lichenoid reaction

Background

It is difficult to distinguish the clinical and histopathological aspects of oral lichen planus lesions from those of oral lichenoid reaction. Some criteria were proposed to distinguish them, mainly because they have different biological behaviors. The aim of the present study was to compare the lymphocyte population and the expression of E-selectin between these lesions.

Methods

Participants with a clinical diagnosis of oral lichen planus (GOLP) and oral lichenoid reaction (GOLR) who needed to perform a biopsy were selected. The tissue was frozen and immunostaining was performed for CD3/CD4, CD3/CD8, CD4/CLA, CD8/CLA, and CD62E. The analysis of each immunostaining was accomplished using the ImageJ program.

Results

In total, 25 participants with oral lichen planus and 11 with oral lichenoid reaction were seen. In the evaluation of CD3 + CD4+/CD3 + and CD3 + CD8+/CD3 + proportions, there was a higher percentage of these cells in the oral lichen planus group when compared with the oral lichenoid reaction group (p = 0.027 and p = 0.038 respectively). The average number of CLA + lymphocytes for CD4+/CLA + and CD8+/CLA + in both groups was not statistically significant (p = 0.840; d = 0.363). In GOLP, the number of CD4 + CLA+/E-selectin and CD8 + CLA+/E-selectin was not statistically significant (p = 0.951 and p = 0.454 respectively); neither in GOLR (p = 0.454 and p = 0.989 respectively).

Conclusion

Our results indicate that CD3 + CD4+, CD3 + CD8+, CD4 + CLA+, CD8 + CLA + lymphocytes and E-selectin are present in both lesions. However, the proportion of CD3 + CD4+/CD3 + and CD3 + CD8/CD3 + cells is higher in the oral lichen planus group when compared with the oral lichenoid reaction group, suggesting that these cells may be important for the etiopathogenic mechanism of these lesions.

Correlation between Oral Lichen Planus and Viral Infections Other Than HCV: A Systematic Review

OBJECTIVES

This review aimed to evaluate the correlation between viral infections (HPV, EBV, HSV-1, CMV) other than HCV and oral lichen planus to assess if there is sufficient evidence to establish if these viruses can play a role in the etiopathogenesis of the disease.

MATERIALS AND METHODS

We reviewed the literature using different search engines (PubMed, ISI Web of Science, and the Cochrane Library), employing MeSH terms such as "oral lichen planus" and "OLP" in conjunction with other terms. We utilized the Population, Intervention, Comparison, Outcomes, and Study design (PICOS) method to define our study eligibility criteria.

RESULTS

A total of 43 articles of the 1219 results initially screened were included in the study. We allocated the 43 selected items into four groups, according to each related virus: HPV, EBV, HSV-1, and CMV.

CONCLUSIONS

Heterogeneous results neither confirm nor exclude a direct correlation between the investigated viral infections and oral lichen planus etiopathogenesis and its feasible malignant transformation. Many viral agents can cause oral lesions and act as cancerizing agents. Future studies could be desirable to produce comparable statistical analyses and enhance the quantity and quality of the outcomes to promote the translation of research into clinical practice.

The Functional Mechanism of MicroRNA in Oral Lichen Planus

Non-coding RNAs (ncRNAs) are transcribed from the genomes of mammals and other complex organisms, and many of them are alternately spliced and processed into smaller products. Types of ncRNAs include microRNAs (miRNAs), circular RNAs, and long ncRNAs. miRNAs are about 21 nucleotides long and form a broad class of post-transcriptional regulators of gene expression that affect numerous developmental and physiological processes in eukaryotes. They usually act as negative regulators of mRNA expression through complementary binding sequences in the 3’-UTR of the target mRNA, leading to translation inhibition and target degradation. In recent years, the importance of ncRNA in oral lichen planus (OLP), particularly miRNA, has attracted extensive attention. However, the biological functions of miRNAs and their mechanisms in OLP are still unclear. In this review, we discuss the role and function of miRNAs in OLP, and we also describe their potential functional roles as biomarkers for the diagnosis of OLP. MiRNAs are promising new therapeutic targets, but more work is needed to understand their biological functions.

The expression of salivary microRNAs in oral lichen planus: Searching for a prognostic biomarker

Oral lichen planus (OLP) is a premalignant disease with unknown etiology. It has been demonstrated that inflammation and immune activation play a central role in the pathogenesis of OLP. Various cellular and molecular mechanisms are involved in the pathogenesis of OLP. Studies have shown that 2-7% of OLP patients develop oral squamous cell carcinoma (OSCC). As a result, determining the prognosis of the disease will be promising in preventing oral carcinoma. MicroRNAs are involved in the regulation of cytokine expression and cytokines have a central role in the pathogenesis of OLP. As a result, their evaluation in body fluids may be helpful in assessing the disease's status and progression, and facilitating the treatment process. In this regard, much attention has been paid to the saliva of OLP patients as the sampling is cost-effective and non-invasive. Here, we discuss the potential of miRNAs in predicting the disease severity and progression.

Risk of anxiety and depression in patients with lichen planus: A nationwide population-based study

BACKGROUND

This study aims to determine the risk of developing anxiety and/or depression among patients with lichen planus.

METHODS

Based on the Longitudinal Health Insurance Database of Taiwan National Health Insurance Research Database, a total of 4012 patients with lichen planus and 16,048 matched controls (1:4) were enrolled between January 1, 2000, and December 31, 2015. After controlling for the risk variables, multivariate Cox proportional hazard regression and the log-rank test with Kaplan-Meier method were performed to assess the influence of anxiety/depression among individuals with lichen planus under a maximum follow-up period of 16 years.

RESULTS

The subsequent anxiety or depression incidence of the lichen planus group and the comparisons was 19.67% (1962.70 per 10⁵ person-years) and 10.11% (982.23 per 10⁵person-years), respectively. Additionally, after adjustment of the risk variables, the hazard ratios for anxiety, depression, anxiety without depression, depression without anxiety, anxiety or depression, and both anxiety and depression combined were 1.779 (95%CI: 1.289-2.477, p < 0.001), 2.010 (95%CI: 1.454-2.790, p < 0.001), 2.015 (95%CI: 1.463-2.799, p < 0.001), 2.356 (95%CI: 1.705-3.286, p < 0.001), 2.011 (95%CI: 1.457-2.793, p < 0.001), and 1.515 (95%CI: 1.100-2.134, p < 0.001), respectively.

LIMITATIONS

Individuals with lichen planus were unable to be classified into oral subtype and cutaneous subtype based on the ICD-9-CM. Moreover, the results of our study could not demonstrate the mechanism between lichen planus and anxiety and/or depression.

CONCLUSION

Patients with lichen planus was positively associated with developing anxiety or depression. Physicians should to be aware of the signs of anxiety and/or depression while facing the patients with lichen planus during the clinical practices.

Does oral lichen planus aggravate the state of periodontal disease? A systematic review and meta-analysis

BACKGROUND

The objective of this systematic review and meta-analysis (SRM) was to assess the evidence between the association of oral lichen planus and periodontal disease, evaluating the periodontal clinical parameters and biomarkers levels.

METHODS

This systematic review and meta-analysis followed PRISMA and was registered in PROSPERO (CRD42020181513). Searches were accomplished in databases for articles published until June 2021. The meta-analysis was performed with the variables: plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (CAL). The mean difference was applied with a 95% confidence interval.

RESULTS

Six articles were included. Qualitative analysis showed the levels of biomarkers (matrix metalloproteinases, interleukins, and periodontal microbiological profile) are increased in subjects with periodontal disease and oral lichen planus. In the meta-analysis, these subjects also presented increases in all periodontal clinical parameters evaluated: GI-gingivitis 0.22 [0.14, 0.31] p < 0.0001 and periodontitis 0.12 [0.06, 0.19] p = 0.0003; PI-gingivitis 0.22 [0.12, 0.31] p < 0.0001 and periodontitis 0.15 [0.08, 0.23] p < 0.0001; PD-gingivitis 0.27 [0.06; 0.48] p = 0.0107 and periodontitis 0.11 [0.01; 0.21] p = 0.0299; and CA-periodontitis 0.06 [0.01, 0.12] p = 0.0176.

CONCLUSIONS

Evidence suggests a significant relationship between the severity of periodontal disease and the presence of oral lichen planus. Although the association is biologically plausible, further studies are needed using populations and well-defined biochemical and clinical outcomes with consideration of potential confounding factors.

CLINICAL RELEVANCE

This SRM provides information on the interaction between OLP and periodontal disease and guides clinicians to make evidence-based decisions and suggests recommendations for further high-quality studies.

Immune mechanisms in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease of the oral mucosa that has been extensively researched over many years but as yet the mechanisms of pathogenesis are still not fully understood. Whilst the specific etiologic factors driving OLP remain ambiguous, evidence points to the development of a chronic, dysregulated immune response to OLP-mediating antigens presented by innate immune cells and oral keratinocytes leading to increased cytokine, chemokine and adhesion molecule expression. These molecules recruit T-cells and mast cells to the diseased site and orchestrate a complex interplay between cells that culminates in keratinocyte cell death, mucosal basement membrane destruction and long-term chronicity of the disease. The main lymphocytes involved are thought to be CD8+ cytotoxic and CD4+ Th1 polarised T-cells although recent evidence indicates the involvement of other Th subsets such as Th9, Th17 and Tregs, suggesting that a more complex immune cell relationship exists during the disease process. This review provides an overview of the immune mechanisms at play in OLP pathogenesis with particular emphasis on the role of the different Th subsets and how these recent discoveries may guide research toward identifying potential therapeutic targets.

Relevant proteins for the monitoring of engraftment phases after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Hematopoietic Stem Cell Transplant (HSCT) has been successfully used as standard therapy for hematological disorders. After conditioning therapy, patients undergoing allogeneic HSCT, present three different phases of engraftment: early pre-engraftment, early post-engraftment, and late engraftment. Severe complications are associated with morbidity, mortality, and malignancies in these phases, which include effects on the oral cavity.

OBJECTIVES

The changes in the salivary composition after HSCT may contribute to identifying relevant proteins that could map differences among the phases of diseases, driven for personalized diagnostics and therapy.

METHODS

Unstimulated whole saliva was collected from patients submitted to HSCT. The samples were submitted to trypsin digestion for a Mass spectrometry analysis. MaxQuant processed the Data analysis, and the relevant expressed proteins were subjected to pathway and network analyses.

RESULTS

Differences were observed in the most identified proteins, specifically in proteins involved with the regulation of body fluid levels and the mucosal immune response. The heatmap showed a list of proteins exclusively expressed during the different phases of HSCT: HBB, KNG1, HSPA, FGB, APOA1, PFN1, PRTN3, TMSB4X, YWHAZ, CAP1, ACTN1, CLU and ALDOA. Bioinformatics analysis implicated pathways involved in protein processing in the endoplasmic reticulum, complement and coagulation cascades, apoptosis signaling, and cholesterol metabolism.

CONCLUSION

The compositional changes in saliva reflected the three phases of HSCT and demonstrated the usefulness of proteomics and computational approaches as a revolutionary field in diagnostic methods.

Efficacy of Systemic Acyclovir as Adjuvant Therapy for Oral Lichen Planus

Patient: Male, 73-year-old

Final Diagnosis: Oral lichen planus (OLP)

Symptoms: Painful tongue • taste impairment

Medication: Acyclovir • antiseptic • corticosteroids • folic acid • vitamin B12

Clinical Procedure: DASS test • medications • OHIP test • serological examinations

Specialty: Dentistry • General and Internal Medicine • Pathology

Inflammatory and immune-related factor Caspase 1 contributes to the development of oral lichen planus

OBJECTIVE

In this study, we aimed at underlying the potential regulatory mechanism and overall biological functions of caspase 1 (CASP1) in oral lichen planus (OLP).

DESIGN

Buccal mucosa tissue samples were gained from healthy subjects or patients diagnosed with OLP. Immunochemical staining was applied to detect CASP1 in OLP tissues. Lipopolysaccharide (LPS) was used to construct OLP in vitro models. Cell counting kit-8 (CCK-8) and flow cytometry assay were applied to detecte cell viability and apoptosis.

RESULTS

The upregulation of CASP1 in OLP has been identified through comprehensive bioinformatics analysis and verified in clinical samples. In OLP tissues, inflammation-related factors, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-6, and IL-18, were elevated and positively correlated with CASP1. In HaCaT cells, LPS stimulation induced CASP1 upregulation, suppressed cell viability, facilitated cell apoptosis, and elevated the levels of TNF-α, IL-1β, IL-6, and IL-18; silencing of CASP1 attenuated LPS-induced damages to HaCaT cells. Pearson's correlation analysis identified that 45 immune-related genes were positively correlated with CASP1; these 45 genes were enriched in the immune system process, associated with combined immunodeficiency, and spleen-specific and CD56 + NK cell-specific. PPI network among CASP1 and correlated immune-related factors was constructed, and CASP1 was positively correlated with RAC2, CYBB, and ARHGDIB. In HaCaT cells, LPS stimulation induced RAC2, CYBB, and ARHGDIB expression, whereas knocking down CASP1 attenuated LPS-induced increases in RAC2, CYBB, and ARHGDIB.

CONCLUSION

CASP1 is upregulated in OLP tissues. Knockdown of CASP1 in HaCaT cells could protect HaCaT cells from LPS-induced inflammatory injury. Comprehensive bioinformatics indicates that the interaction of CASP1 with RAC2, CYBB, and ARHGDIB, might be the potential molecular mechanism.

[Efficacy and safety of Nocardia rubra cell wall skeleton for the treatment of erosive oral lichen planus]

OBJECTIVE

To observe the efficacy and safety of Nocardia rubra cell wall skeleton (Nr-CWS) for the treatment of erosive oral lichen planus (EOLP).

METHODS

Sixty patients with clinically and pathologically diagnosed EOLP were randomly divided into the experimental group and control group according to the random number. Patients in the experimental group were treated with lyophilized powder containing Nr-CWS combined with normal saline. Patients in the control group received topical placebo without Nr-CWS combined with normal saline. Changes in the EOLP lesion area and the patient's pain level were recorded at the timepoints of weeks 1, 2, and 4 after the two different treatments, respectively. The changes of the patient's REU scoring system (reticulation, erythema, ulceration), the visual analogue scale and the oral health impact score (OHIP-14) were compared between the experimental group and control group after treatment, and the safety indicators of the two groups at the initial diagnosis and after 4 weeks' treatment were also observed, respectively.

RESULTS

Totally, 62 patients with clinically and pathologically diagnosed EOLP were enrolled, 2 of whom were lost to the follow-up, with 31 in the experimental group, and 29 in the control group. The mean age of the experimental group and control group were (52.9±12.4) years and (54.07±12.40) years, respectively. There was no significant difference in the oral periodontal index between the experimental group and control group. In the experimental group, the erosive area of oral lichen planus was significantly reduced 1, 2, and 4 weeks after the Nr-CWS's treatment (P < 0.05), the reduction rate was 81.75%, the patient's pain index was also decreased (P < 0.05), and in addition, the OHIP-14 was reduced (P < 0.05). The changes of the REU scoring system, the visual analogue scale and the OHIP-14 were significantly different between the experimental group and control group after treatment. There was no significant difference in the safety index between the two groups.

CONCLUSION

The priliminary data show that the Nr-CWS is effective and safe to treat EOLP.

Characterization and function of circulating mucosal-associated invariant T cells and γδT cells in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory disease with uncertain aetiology. Mucosal-associated invariant T (MAIT) cells and γδT cells are unconventional, innate-like T cells with immunoregulatory capacity. This study aimed to investigate the potential effects of MAIT and γδT cells on the pathogenesis of OLP.

METHODS

Circulating MAIT cells and γδT cells were identified using flow cytometry. Surface proteins including CD4, CD8, CD69, CD103, CD49d, programmed death-1 (PD-1) and its ligand PD-L1 were assessed. Cytokines containing interleukin (IL)-4, IL-17, interferon (IFN)-γ, granzyme B and tumour necrosis factor (TNF)-α released by MAIT and γδT cells were measured following PMA and ionomycin stimulation.

RESULTS

Circulating MAIT and γδT cells were deficient in OLP. The percentage of CD4⁺ , CD69⁺ , CD103⁺ and PD-1⁺ MAIT cells was increased in OLP, while that of CD8⁺ and CD49d⁺ MAIT cells was decreased. The percentage of CD103⁺ , PD-1⁺ and PD-L1⁺ γδT cells was upregulated in OLP. Both the MAIT and γδT cells in OLP produced less IL-4 than controls. The granzyme B-producing MAIT cells were increased, while γδT cells secreting granzyme B and TNF-α were reduced in OLP. IL-17 and IFN-γ in OLP MAIT and γδT cells were not significantly different from that in controls. The frequency of OLP MAIT cells and the MAIT/γδT rate were positively associated with the disease severity.

CONCLUSION

The deficient MAIT and γδT cells expressing functional proteins and releasing cytokines may play an immunoregulatory role in the pathogenesis of OLP.

Systematic Review and Meta-Analysis of Oxidative Stress and Antioxidant Markers in Oral Lichen Planus

Background

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease of unknown etiology, which might be caused by oxidative stress and impaired antioxidant defense.

Objective

To systematically investigate the markers of oxidative stress and antioxidant systems in the saliva and blood from OLP patients and healthy controls.

Methods

The PubMed, Cochrane Library, and Embase were systematically queried to collect data from studies in which oxidative stress/antioxidant markers from OLP and healthy subjects had been evaluated until March 10, 2021.

Results

A total of 28 studies fulfilled inclusion criteria, and 25 of them, having 849 OLP patients and 1,052 control subjects and analyzing 12 oxidative stress and antioxidant state marker levels, were subjected to meta-analysis. We found a significant decrease in total antioxidant capacity (TAC) and uric acid (UA) and a significant increase in malondialdehyde (MDA) and nitric oxide (NO) levels in the saliva and serum/plasma of OLP patients. Moreover, a significant elevation of 8-hydroxy-deoxyguanosine (8-OHdG) and advanced oxidation protein product (AOOP) level and a decrease in vitamin C were also observed in the saliva of the OLP group. In contrast, salivary vitamin A, zinc, glutathione peroxidase (GPx), vitamin E, and nitrite were not significantly different between the two groups. In single studies, markers of oxidative stresses such as superoxide dismutase (SOD) and 8-isoprostanelevels were elevated in OLP, and antioxidant parameters such as glutathione (GSH) and total protein (TP) levels were dysregulated.

Conclusion

This meta-analysis helps to clarify the profile of oxidative stress and antioxidant state markers in OLP patients although existing evidence is rather heterogeneous and many studies are affected by several limitations. Larger and more standardized studies are warranted to ascertain whether these markers are potential causes or effects of OLP and whether antioxidant therapy improving oxidative stress will be useful.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

RESULTS

The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

CONCLUSIONS

Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

CLINICAL RELEVANCE

TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.

Cross-talk between CXC chemokine ligand 10-CXC chemokine receptor 3 axis and CC chemokine ligand 17-CC chemokine receptor 4 axis in the pathogenesis of oral lichen planus

OBJECTIVES

This study aimed to determine whether a correlation existed between CXC chemokine ligand 10 (CXCL10)-CXC chemokine receptor 3 (CXCR3) and CC chemokine ligand 17 (CCL17)-CC chemokine receptor 4 (CCR4) in the pathogenesis of oral lichen planus (OLP).

METHODS

Peripheral blood of OLP patients (non-erosive and erosive groups) and healthy controls were collected, and T cells were isolated and purified. T cells were co-cultured with three groups: blank, anti-CXCR3, and anti-CCR4. CXCR3 and CCR4 expression were detected by flow cytometry, and CXCL10 and CCL17 were detected by enzyme-linked immunosorbent assay, respectively.

RESULTS

The purities of T cells were all >95% in the three groups (P>0.05). Receptor expression showed that CXCR3 and CCR4 in the anti-CXCR3 group was downregulated in OLP compared with the blank group (P>0.05). The level of CCR4 in the anti-CCR4 group was significantly downregulated (P<0.05), and CXCR3 was upregulated (P>0.05). Ligand analysis results showed that CXCL10 in the anti-CXCR3 group was significantly downregulated in OLP compared with the blank group (P<0.05), and CCL17 was also downregulated (P>0.05). CCL17 in the anti-CCR4 group was significantly downregulated (P<0.05), and CXCL10 was upregulated (P>0.05). The trend of receptors and ligands in controls was consistent with OLP, but no significant difference existed between the antagonistic and the blank groups (P>0.05).

CONCLUSIONS

Two axes interact with each other in the pathogenesis of OLP and may play different roles in its occurrence and development.

An association of the MCP-1 and CCR2 gene polymorphisms with oral lichen planus

OBJECTIVE

The purpose of this study was to investigate the frequency of monocyte chemoattractant protein (MCP)-1 CCR2 gene polymorphisms in Turkish patients with oral lichen planus (OLP).

STUDY DESIGN

A cohort of 50 patients with OLP and 142 control participants without OLP were recruited to investigate the frequency of MCP-1 and CCR2 gene polymorphisms. Chi-square and Fisher's exact tests were used. Student t test and analysis of variance were used to compare demographic data between groups.

RESULTS

The MCP AA genotype was less common in the patient group (52%) than in the control group (66.2%; odds ratio [OR] = 0.553; 95% confidence interval [CI], 0.287-1.065; P = .075). The MCP G allele was higher in the patient group (48%) than in the control group (33.8%; OR = 1.808; 95% CI, 0.939-3.479; P = .075). The frequency of the MCP GG genotype was observed to be higher in the patient group (4%) than in the controls (0.7%; OR: 5.875, 95% CI:0.521-66,24; p = 0.106). The CCR2 64I64I genotype was more common in the patient group (6%) than in the control group (2.8%). All results were not statistically significant.

CONCLUSION

We suggest that the G allele of MCP-1 and 64I64I genotype of CCR2 polymorphisms do not pose an increased risk for Turkish patients with OLP to develop oral squamous cell carcinoma.

Horoscopic role of CD105 (Endoglin) in progression of oral lichen planus: An immunohistochemical study

Context

Role of CD105(Endoglin) in Pathogenesis and progression of OLP.

Aim

To assess the role of neoangiogenesis in the progression of OLP by determining the expression of CD105 in OLP and normal mucosa.

Settings and Design

The present study includes a total of 70 formalin-fixed paraffin-embedded blocks of which the study group comprises 50 tissue sections histopathologically confirmed as OLP. They were subdivided into two groups - Group I (Reticular OLP) and Group II (Erosive OLP) - 25 each. The control group (designated as Group III) included 20 sections of normal mucosa.

Materials and Methods

All the sections were 4 μm thick and stained with CD105 antibodies. After identifying areas of highest vascularity (hot spots) in low power (×10) magnification, individual microvessels were counted manually at high power (×40) magnification.

Statistical Analysis Used

Analysis of variance test was used to determine the difference of microvessel density (MVD) between variants of OLP and normal mucosa and Cohen's kappa statistic was used to check interobserver variability.

Results

CD105 staining showed a mean MVD of 1.31 ± 1.8 in the normal mucosa compared to 1.68 ± 1.4 and 4.14 ± 2.7 in the reticular and erosive variants, respectively, with a P = 0.000*, which is statistically significant (*P < 0.05 is statistically significant).

Conclusion

Based on our observations, it is evident that compared to normal mucosa, MVD is greater in lichen planus. Within the two variants of OLP, MVD is higher in Erosive variant compared with Reticular variant, foreshadowing the role of neoangiogenesis in the progression of OLP and its possible malignant transformation.

New markers of oxidative stress in lichen planus and the influence of hepatitis C virus infection - a pilot study

INTRODUCTION

Lichen planus (LP) is a mucocutaneous T-cell mediated disorder of unknown etiology. There is growing evidence that oxidative stress is an important player in the pathogenesis of LP. Therefore, we have investigated oxidative stress markers in LP and the influence of hepatitis C virus (HCV) infection, a frequently associated condition, on oxidative stress in LP patients.

METHOD

We have determined the serum levels of 4- hydroxynonenal (4-HNE) and symmetric dimethylarginine (SDMA), as markers of oxidative stress, and total antioxidant capacity (TAC), as a marker of the antioxidant defence, in 4 groups: group A - HCV positive patients with LP (n=12), group B - HCV positive patients without LP (n=12), group C - HCV negative patients with LP (n=31) and group D - control group (n=26).

RESULTS

In LP patients, we have identified an increased level of lipid peroxidation (4-HNE - group A - 8.41±1.11 µg/mL, group B - 7.97±2.17 µg/mL, group C - 7.81±1.96 µg/mL and group D - 6.15±1.17 µg/mL) and alterations in arginine methylation (SDMA - group A - 1.10±0.24 µmol/L, group B - 1.03±0.16 µmol/L, group C - 0.84±0.19 µmol/L and group D - 0.50±0.06 µmol/L) associated with a diminished antioxidant defence (TAC - group A - 234,50±49,96, µmol/L group B - 255,83±41,41 µmol/L, group C - 269,83±43,33 µmol/L and group D - 316,46 ±29,33 µmol/L), processes augmented by the association with HCV infection.

CONCLUSION

There is an imbalance between oxidants and antioxidants in patients with LP, an imbalance that is augmented by the presence of HCV infection. SDMA could be regarded as a novel biomarker of oxidative stress among these patients. To the best of our knowledge this is the first study to investigate the influence of HCV infection on oxidative stress in LP patients.

Helicobacter pylori infection is correlated with the incidence of erosive oral lichen planus and the alteration of the oral microbiome composition

BACKGROUND

Oral lichen planus (OLP), a common clinical oral disease, is associated with an increased risk of malignant transformation. The mechanism underlying the pathogenesis of OLP is unknown. Oral dysbacteriosis is reported to be one of the aetiological factors of OLP. Although Helicobacter pylori infection is associated with various oral diseases, the correlation between H. pylori infection and OLP is unclear. This study aimed to investigate the effect of H. pylori infection on OLP pathogenesis and oral microbiome composition in the Chinese population, which has a high incidence of H. pylori infection.

RESULT

In this study, saliva samples of 30 patients with OLP (OLP group) and 21 negative controls (NC group) were collected. H. pylori infection was detected using the carbon-13-labeled urea breath test (UBT). The saliva samples were divided into the following four groups based on the H. pylori status: H. pylori-positive OLP (OLP+), H. pylori-positive NC (NC+), H. pylori-negative OLP (OLP-), and H. pylori-negative NC (NC-). Oral microbiome compositions were significantly different between the OLP and NC groups and between the OLP- and OLP+ groups. Compared with those in the OLP- group, those in the OLP+ group had a higher incidence of erosive OLP and higher levels of salivary cytokines. In contrast, the oral microbiome composition and cytokine levels were not significantly different between the NC- and NC+ groups.

CONCLUSIONS

This is the first report to demonstrate that H. pylori infection is significantly correlated with the pathogenesis of erosive OLP.

The presence of Prevotella melaninogenica within tissue and preliminary study on its role in the pathogenesis of oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is a chronic inflammatory disease that occurs in the oral mucosa with characteristic white striations lesions, recurrent erosions, and pains. The etiology and pathogenesis of OLP are still unclear.

MATERIALS AND METHODS

We analyzed the bacterial community structure of buccal mucosa in patients with OLP and normal controls by high-throughput sequencing. Fluorescence in situ hybridization (FISH) was used to detect Prevotella melaninogenica (P. melaninogenica) in 13 OLP samples and 10 controls. The amounts of P. melaninogenica in OLP buccal mucosa and the expression of inflammatory cytokines in co-culture of mouse-derived macrophages with P. melaninogenica were detected by RT-qPCR.

RESULTS

The P. melaninogenica was more abundant in OLP than in healthy controls, and the differences were significant at the level of the phylum, family, genus, and species (p < .05). FISH showed that P. melaninogenica can invade the epithelium and even the lamina propria of OLP, while no invasion was found in the normal mucosa. Prevotella melaninogenica can adhere to and invade macrophages and then activate the transcription of IL-1β, IL-6, and TNF-α in NF-κB signaling pathway.

CONCLUSION

Prevotella melaninogenica may be involved in the pathogenic process of OLP, and its specific mechanism deserves further study.

Photobiomodulation Therapy/Photodynamic Therapy Versus Steroid Therapy for Oral Lichen Planus: A Systematic Review and Meta-Analysis

Objective: To evaluate the efficiency of photobiomodulation therapy (PBMT) or photodynamic therapy (PDT) in treating oral lichen planus (OLP) as well as identifiy the side effects when compared with steroid therapy. Background: Nowadays, PBMT and PDT are increasingly applied for treating OLP with minimal adverse effects. Methods: The electronic databases of PubMed, Cochrane Central Register of Controlled Trial, Web of Science, and Embase were searched until March 13, 2020. Randomized controlled trials (RCTs) with 1 month of follow-up period were selected. Two reviewers extracted data from selected studies independently. Cochrane collaboration's tool for assessing risk of bias was used for assessing the quality of the RCTs. The random-effects model was employed for meta-analysis. Results: One thousand fifteen studies were initially identified. Finally, nine RCTs were included for quality assessment and seven studies for meta-analysis. Four RCTs were of unclear risk of bias and five were assessed as high risk of bias. The comparison showed no significant differences for pain scores [visual analog scale (VAS)] [mean differences (MD) = 0.38, confidence interval (CI) = 95% -0.64 to 1.40] and severity scores (reticular-atrophic-erosive scores) (MD = 1.67, CI = 95% -1.13 to 4.46) between topical corticosteroid therapy and PBMT after 1 month. For PDT, no significant differences were observed for sign scores (Thongprasm sign scoring) (MD = -0.31, CI = 95% -1.52 to 0.91) and pain scores (VAS) (MD = -2.30, CI = 95% -5.88 to 1.28) of the lesions when compared with topical corticosteroid therapy after 1 month of follow-up period. One study reported the discomfort of the affected area in patients of the PDT group when probe tip was moved. Conclusions: PBMT and PDT could be reliable alternatives to topical corticosteroids for OLP with no or less severe complications in a short-term period. However, further well-designed RCTs with long-term period are recommended to consolidate the conclusions in this regard.

T cell-derived exosomes containing cytokines induced keratinocytes apoptosis in oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is a T cell-mediated inflammatory disease with uncertain etiology. Exosomes are cell-derived vesicles containing biological cargo, being associated with the development of multiple inflammatory diseases. The present study aims to investigate the role of T cell-derived exosomes in the pathogenesis of OLP.

METHODS

Exosomal marker CD63 was detected in OLP lesions by immunohistochemistry. Twenty-three cytokines in T cell-derived exosomes were assessed using luminex xMAP-based assay. After co-incubating with exosomes, the apoptosis of keratinocytes and the proliferation of Jurkat cells were assessed via flow cytometry and cell counting kit-8 assay, respectively.

RESULTS

CD63 was highly expressed in the lymphocyte infiltrated areas of OLP lesions. OLP T cell-derived exosomes contained upregulated interleukin-7, -10, -12, -17 and downregulated interleukin-1β, -5, and interferon-γ. Both exosomes from OLP patients and controls induced the apoptosis of keratinocytes and altered their morphology. Moreover, healthy control-derived exosomes markedly inhibited the proliferation of Jurkat cells, whereas OLP-derived exosomes exhibited no inhibitory effect.

CONCLUSIONS

OLP T cell-derived exosomes have an aberrant cytokine profile and could trigger the apoptosis of keratinocytes in vitro, which may be involved in the pathogenesis of OLP.

Efficacy of platelet-rich fibrin compared with triamcinolone acetonide as injective therapy in the treatment of symptomatic oral lichen planus: a pilot study

OBJECTIVES

Oral lichen planus (OLP) is a chronic immune-mediated disease that affects the oral cavity. Topical steroids are considered the treatment of choice for painful lesions of OLP. The aim of this split-mouth study was to compare the efficacy of platelet-rich fibrin (PRF) and triamcinolone acetonide (TA) injective therapies in patients with symptomatic OLP.

MATERIALS AND METHODS

Participants with symptomatic OLP were recruited in the Academic Hospital of Magna Graecia University of Catanzaro, Italy. Once a week for a month, patients randomly received a 0.5-mL TA injection in one buccal mucosa and 1-mL PRF injection in the opposite side. The measured outcomes were reduction of the lesions area and symptomatology modifications using visual analogue scale (VAS) score RESULTS: Four weeks after the last injections, an average reduction of 59.8% in the lesion extension and an average reduction of 47.6% in the VAS score for PRF-treated sites were observed; the same variation for TA-treated sites was respectively of 59.2% and 40%. There were no statistically significant differences between the two groups.

CONCLUSIONS

PRF was effective in reducing OLP lesions extension and symptomatology, and it seems to be as effective as TA. Additional data should be collected with a larger sample size, at a longer follow-up and on the PRF lowest effective dose.

CLINICAL RELEVANCE

Current treatment options for OLP are limited. The study proved benefits of PRF injections in management of painful lesions of OLP comparable with TA.

Examination of Oral Squamous Cell Carcinoma and Precancerous Lesions Using Proximity Extension Assay and Salivary RNA Quantification

Saliva is an easy-to access body fluid with high diagnostic potential. The utilization of saliva for oral cancer diagnosis can be an attractive possibility. Besides the oral cancer, it is important to better understand the precancerous lesions such as oral lichen planus (OLP) and leukoplakia (OLK). In order to examine the changes of salivary proteins in controls, patients with oral cancer, and patients with precancerous conditions, proximity extension assay was utilized. Some proteins and functions were characteristic to the examined groups and can serve as a starting point for further biomarker studies. The different nature of OLK and OLP was demonstrated, showing the malignant transformation and the inflammation as the prominent biological processes in the OLK and OLP, respectively. The salivary level of IL6 was verified using quantitative ELISA and the mRNA level was also studied. Elevated IL6 levels could be detected in precancerous groups compared to controls.

Treatment trends in oral lichen planus and oral lichenoid lesions (Review)

Oral lichen planus (OLP) is a chronic inflammatory disease, associated with altered cell-mediated immunological function. It has long-term evolution, repeated exacerbations, sometimes painful and resistant to treatment, even all of these, OLP significantly affects patient's life quality. Not least, OLP is accompanied by an increased risk of malignant transformation. A wide spectrum of therapeutic options is available, but none are curative. In this review, 58 structured studies on the clinical symptomatology and treatment strategy of OLP were analyzed. The literature research was performed according to the criteria of the PRISMA system. This study summarizes current knowledge regarding management of OLP and oral lichenoid lesions, discusses the challenges of choosing an adequate treatment and, in attempt to improve the quality of patient life, trying to describe a therapeutic algorithm that takes into consideration the clinical features of the disease. Current OLP therapy aims at eliminating all mucosal-related lesions, reduce symptomatology and decrease the risk of oral cancer and include corticosteroids, immunomodulatory agents, retinoids, ultraviolet irradiation and/or laser therapy.

Photobiomodulation is effective in oral lichen planus: A randomized, controlled, double-blind study

OBJECTIVES

To compare the efficacy of photobiomodulation to that of topical clobetasol 0.05% in patients with symptomatic oral lichen planus (OLP).

SUBJECTS

Thirty-four patients with symptomatic OLP were randomly allocated into two groups: (a) the Control group (n = 17), application of topical clobetasol propionate 0.05% three times a day for 30 consecutive days with laser placebo applied twice a week to mask the treatment, and (b) the photobiomodulation group (n = 17), laser application twice a week, totalling 8 sessions, and gel placebo for 30 consecutive days to mask the treatment. Evaluations were performed once a week during treatment and 30, 60 and 90 days after treatment. The following parameters were evaluated: pain, clinical scores, clinical resolution and recurrence rate.

RESULTS

Photobiomodulation and propionate clobetasol 0.05% were able to significantly decrease pain in oral lichen planus patients and improve clinical scores during treatment and follow-up. Both the Control and photobiomodulation groups presented similar clinical resolution and recurrence rates. Most importantly, no difference was observed between treatments during treatment and follow-up.

CONCLUSIONS

These findings indicate that photobiomodulation twice a week is as effective as corticoid therapy in treating oral lichen planus. Moreover, photobiomodulation is a safe and non-invasive therapy with the remarkable advantage of no adverse effects.

Comparative evaluation of effectiveness of autologous platelet rich plasma and intralesional corticosteroids in the management of erosive oral Lichen planus- a clinical study

Purpose

Oral Lichen planus is a potentially malignant autoimmune disorder, characterized by burning and pain in the affected mucosa which reduces the quality and comfort of patient's life. Various treatment modalities have been documented for OLP but due its malignant potential the alternative therapeutic approaches with least or no side effects are being in demand. One of such, yet unexplored treatment is Platelet rich plasma (PRP). This study aims to evaluate the effectiveness of intralesional PRP as compared to the Intralesional corticosteroids in the management of erosive OLP.

Materials and methods

The study sample consisted of 20 clinically and histopathologically confirmed patients of Erosive OLP among which 10 patients were given intralesional corticosteroids and 10 patients were administered intralesional PRP. All the patients were given weekly injections for 2 months and were followed up till 4 months for assessing the parameters such as pain/burning, erythema and size of the lesions.

Results

The patients in both the groups showed a statistically significant reduction in all the assessed parameters of erosive lichen planus from baseline till 4 months of treatment and follow up. However, on comparison of the pain reduction, size of lesion and erythema scores between the two groups, the difference was found to be statistically insignificant.

Conclusion

The intralesional PRP was found to be of comparative effectiveness with respect to intralesional triamcinolone acetonide in the management of erosive OLP and with an added advantage of having less recurrence and no adverse effects.

Diagnostic Criteria of Oral Lichen Planus: A Narrative Review

Oral lichen planus (OLP) is a disease with unclear etiology or pathogenesis, categorized by the World Health Organization as oral lichenoid lesions (OLL; interface mucositis or lichenoid mucositis) into a group of potentially malignant disorders. The diagnosis of OLP is challenging because the clinical and histopathologic features are frequently seen in OLP, OLL and/or other mucosal diseases with lichenoid characteristics. Furthermore, OLP has a dynamic nature. Finally, an early and precise diagnosis can play a decisive role, allowing timely treatment and thus improving the patient quality of life. This article summarizes the state-of-the-art regarding OLP and OLL and discusses the challenges faced on making an accurate diagnosis, aiming to provide a practical guideline for the postgraduates and oral physicians in reaching the diagnosis of these lesions.

Omega-3 polyunsaturated fatty acids: a promising approach for the management of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease with a risk of malignant transformation. Although the etiology of OLP is still uncertain, growing evidence suggests that oral microbiota, antigen-specific, and non-specific mechanisms are involved in the pathogenesis of OLP. Antigen-specific mechanisms include antigen presentation, T-cell activation, nuclear factor-kappa B signaling pathway, and cytokine secretion, while non-specific mechanisms consist of matrix metalloproteinases (MMP)-9 upregulation, psychological pressure, oxidative damage, aberrant expression of microRNAs (miRNAs), and autophagy. Till now, there is no cure for OLP, and the main purpose of OLP therapy is symptomatic control.

FINDING

Seafood and its derivative omega-3 polyunsaturated fatty acids (n-3 PUFAs) can suppress antigen presentation, T-cell activation, and nuclear factor-kappa B signaling pathway, modulate the overexpressed inflammatory cytokines, inhibit the expression of MMP-9, as well as regulate the expression of miRNAs and autophagy. And they are possible agents for ameliorating psychological disorder and oxidative damage. Moreover, n-3 PUFAs supplementation has a beneficial effect on preventing tumorigenesis.

CONCLUSION

n-3 PUFAs consumption may provide a non-toxic, inexpensive administration for OLP.

Applying dental implant therapy in patients with oral lichen planus: a review of literature

Lichen planus (LP) is a violent, paranormal inflammatory disease that can affect the skin or any lining of the mucous membrane. LPs are a branch of immune-mediated inflammatory disease (IMID) that collaborates with the function and structure of the immune system that are precipitated through various etiological infectious agents. Oral lichen planus (OLP) is one of the most common kinds of IMID. These traumas might limit the normal life of patients and, in some cases, can be treated spontaneously. In patients who are affected by OLP, the dental clinicians must be capable of the proper diagnosis of the disorder. Dental implants are progressively applied for the treatment of partial or complete edentulism. Implant rehabilitation in OLP patients is one of the main challenges for patients and dental clinicians. There is not enough knowledge about this condition, and also medical documents are limited. In this study, by conducting a comprehensive review of literature, we tried to collect related data around the safety and success rate of implant rehabilitation in patients who suffer from OLP disorder. There proved to be no relation between implant survival rate and OLP diseases, but it is proven that some factors such as bone quality and fracture resistance, parafunctional habits, and resection of the marginal mandible could powerfully affect it. For evaluation of the advantages and disadvantages of applying implants in patients with OLP disorders, implementation of controlled studies is required.

Oral lichen planus: a novel staging and algorithmic approach and all that is essential to know

Lichen planus (LP) is a chronic autoimmune disease. Oral lesions may occur in isolation or in combination with other affected muco-cutaneous sites. Oral LP (OLP) may present as one of the various manifestations of LP or may present as a disease sui generis with a broad range of severity. Despite this disease targeting the oral mucosa, its great impact on quality of life is underrated. In this article, we provide an updated review of the pathophysiology and epidemiology of OLP and offer guidance for its diagnosis and management. We also propose an algorithmic approach to the clinical forms of OLP and a novel staging system to facilitate management decisions.

Vitamin D receptor genetic polymorphisms are associated with oral lichen planus susceptibility in a Chinese Han population

BACKGROUND

Vitamin D receptor (VDR) is involved in multiple immune-mediated disorders including oral lichen planus (OLP). This study investigated the association between VDR gene polymorphisms and the risk of OLP.

METHODS

In total, 177 OLP patients and 207 healthy participants were recruited from the Affiliated Hospital of Stomatology, Nanjing Medical University. Eight single nucleotide polymorphisms (SNPs: rs731236, rs739837, rs757343, rs2107301, rs2239185, rs7975232, rs11574129 and rs11568820) in the VDR gene were selected and genotyped.

RESULTS

The results showed that OLP risk was increased in subjects with the rs2239185 TT genotype (Recessive model: adjusted Odd ratio(OR) = 2.68, 95% Confidence interval(CI) = 1.28-5.62, P = 0.009) and rs7975232 CC genotype (Recessive model: adjusted OR = 2.25, 95% CI = 1.10-4.58, P = 0.026). Moreover, rs2239185 and rs7975232 (P < 0.01) showed significant cumulative effects on OLP risk.Haplotype analysis showed that the CC haplotype (rs2239185-rs7975232) was associated with an increased risk of OLP (OR = 3.11, 95% CI = 1.42-6.83, P = 0.005), compared with the AC haplotype.

CONCLUSION

The rs2239185 and rs7975232 variants of VDR may influence OLP susceptibility, and VDR gene polymorphisms may be candidate susceptibility regions for OLP in a Chinese Han population.

Could photodynamic therapy be utilized as a treatment modality for oral lichen planus?

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory disease. There is no standard treatment modality for OLP. Recently, photodynamic therapy (PDT) has been advocated as a new treatment modality for OLP.

AIM

The aim of the present study is to compare the effect of PDT using methylene blue (MB) as a photosensitizer to the effect of topical corticosteroids in the treatment of erosive OLP lesions.

MATERIALS AND METHODS

Our study included 20 patients with erosive OLP. Patients were divided into two groups. The study group included 10 patents which received MB-PDT. Patients were instructed to use MB as mouth path for 5 min. After 10 min, we applied focal red light on OLP lesions (wavelength 660 nm, Intensity 100-130 m W/cm2) for 2 min. The PDT was applied twice a week for four weeks. In the control group, 10 patients were instructed to apply topical betamethasone valerate ointment 100 mg on OLP lesion three times per day for four weeks. Subjective, objective scores and lesion size were recorded at time zero, after 2 weeks and after 4 weeks from the start of treatments.

RESULTS

Both groups showed statistically significant differences between time zero and the 4^th week of treatment in subjective, objective scores and the area of the lesions. MB-PDT showed a higher degree of improvement than topical corticosteroids between time zero and the 4^th week of treatment.

CONCLUSION

Photodynamic therapy can be used as a treatment for erosive OLP. PDT offers improvement of OLP subjective and objective scores without major side effects.

Metabolic changes during malignant transformation in primary cells of oral lichen planus: Succinate accumulation and tumour suppression

Oral squamous cell carcinoma (OSCC) is usually diagnosed at late stages, which leads to high morbidity. There are evidence that chronic inflammation (eg oral lichen planus [OLP]) was a risk factor of OSCC, but often misdiagnosed or ignored until invasion and metastasis. By applying precision medicine, the molecular microenvironment variations and relevant biomarkers for the malignant transformation from OLP to OSCC can be fully investigated. Several studies pointed out that the metabolic pathway were suppressed in OSCC. However, it remains unclear how the systemic profile of the metabolites change during the malignant transformation. In this study, we examined and compared the mucosa samples from 11 healthy individuals, 10 OLP patients and 21 OSCC patients. Based on the results, succinate, a key metabolite of the tricarboxylic acid cycle pathway, was accumulated in the primary cultured precancerous OLP keratinocytes and OSCC cells. Then, we found that succinate activated the hypoxia‐inducible factor‐1 alpha (HIF‐1α) pathway and induced apoptosis, which could also be up‐regulated by the tumour suppressor lncRNA MEG3. These results suggested the critical roles of succinate and MEG3 in the metabolic changes during malignant transformation from OLP to OSCC, which indicated that succinate, HIF1α and downstream proteins might serve as new biomarkers of precancerous OLP for early diagnosis and therapeutic monitoring. In addition, succinate or its prodrugs might become a potential therapy for the prevention or treatment of OSCC.