Oral lichen planus: an update on its pathogenesis

Hydroxychloroquine for the management of recalcitrant oral lichen planus

OBJECTIVE

The objective of this study is to describe the efficacy of hydroxychloroquine (HCQ) in patients with oral lichen planus (OLP) refractory to conventional therapy.

STUDY DESIGN

In this single-center retrospective study, patients were prescribed HCQ 200 mg twice daily. Pain, reticulation, erythema, and ulceration scores were recorded. Two-sample and paired t tests were used to evaluate mean and paired pain scores and paired t test to determine substantial differences in paired REU scores, at HCQ initiation visit and final follow-up at 12 to 24 months.

RESULTS

Thirty-six patients (69.4% female) with a median age of 70 ± 12.0 (range 48-99) were initiated on HCQ. Only 30 patients were evaluable because pruritus developed in 5 patients (13.9%) and gastrointestinal symptoms in 1 (2.8%). The mean follow-up was 23.2 months (range 1-74). In 19 patients, there was a significant decline in the worst pain score from a mean of 3.9 (SD± 2.8, n = 19) to 1.9 (SD ± 2.4, n = 19) (t = 2.837, P < .006). Paired reticulation, erythema, and ulceration (REU scores) decreased from a weighted mean score of 16.0 (SD ± 8.0, n = 12) to 12.0 (SD ± 6.3, n = 12) (t = 2.07, P < .032).

CONCLUSION

Hydroxychloroquine was a suitable option and effective in reducing symptoms and disease severity in patients with recalcitrant OLP who do not adequately respond to standard therapy.

Inflammatory cytokines and oral lichen planus: a Mendelian randomization study

Background

Inflammatory cytokines have long been considered closely related to the development of oral lichen planus (OLP), and we further explored the causal relationship between the two by Mendelian randomization (MR) method.

Methods

We performed bidirectional MR analyses by large genome-wide association studies (GWAS). The data included a large-scale OLP dataset, as well as datasets of 41 inflammatory cytokines. All data were obtained from the University of Bristol database, which includes 41 inflammatory cytokines, and the GWAS Catalog database, which includes 91 inflammatory cytokines. OLP data were obtained from the Finngen database, which includes 6411 cases and 405770 healthy controls. We used the inverse variance weighted (IVW) method, MR-Egger method, weighted median method, simple mode method and weighted mode method to analyze the causal relationship between inflammatory cytokines and OLP, and we also combined with sensitivity analysis to further verify the robustness of the results. We performed a meta-analysis of positive or potentially positive results for the same genes to confirm the reliability of the final results.

Results

We primarily used the IVW analysis method, corrected using the Benjamin Hochberg (BH) method. When p<0.00038 (0.05/132), the results are significantly causal; when 0.00038

Conclusion

There is a causal association between OLP and some inflammatory cytokines, which may play an important role in the pathogenesis of OLP and require further attention.

Collapse

Key Words

• Mendelian randomization
• immunity
• inflammation
• inflammatory cytokines
• oral lichen planus

Collapse

MESH Headings

• Humans
• Cytokines/genetics
• Genome-Wide Association Study
• Lichen Planus, Oral/genetics
• Mendelian Randomization Analysis
• Reproducibility of Results

Collapse

Grants Collapse

Affiliation(s)

Xin Chen Department of Oral and Maxillofacial Surgery, Jiangyin People's Hospital Affiliated to Nantong University, Wuxi, Jiangsu, China
Simin Zhang Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Xiao Wu Endodontic Department, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu, China
Yuxi Lei Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of Emergency Room, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Bing Lei Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Zhibai Zhao Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China Department of General Dentistry, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, China

Collapse

Effect of zinc supplementation as an adjuvant to corticosteroid treatment in patients with oral lichen planus: A systematic review

Background

Oral lichen planus (OLP) and one of its main presentations, desquamative gingivitis, are common diseases with no definite treatment. Zinc deficiency has a critical role in the pathogenesis of oral mucosal diseases. The current study systematically reviewed the effect of zinc in addition to topical corticosteroids in the treatment of OLP.

Methods

English articles in PubMed, Web of Sciences, Embase, and Scopus were searched until August 2022. The differences in symptoms were analyzed, including pain, burning sensation, and lesion sizes in patients with lichen planus receiving zinc supplementation as an adjuvant to corticosteroid treatment.

Results

A total of 148 articles related to the searched keywords were found. Eventually, two clinical trials were selected. The total population of studied individuals included 60 patients. Due to the high heterogeneity between the studies, meta-analysis was not possible. Administering zinc, in addition to corticosteroids, did not improve the symptoms compared to corticosteroid monotherapy.

Conclusion

Considering the limited number of studies and lack of sufficient evidence, it is not currently possible to reach a definite conclusion regarding the effects of zinc on OLP.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Salivary Exosomes in Health and Disease: Future Prospects in the Eye

Exosomes are a group of vesicles that package and transport DNA, RNA, proteins, and lipids to recipient cells. They can be derived from blood, saliva, urine, and/or other biological tissues. Their impact on several diseases, such as neurodegenerative, autoimmune, and ocular diseases, have been reported, but not fully unraveled. The exosomes that are derived from saliva are less studied, but offer significant advantages over exosomes from other sources, due to their accessibility and ease of collection. Thus, their role in the pathophysiology of diseases is largely unknown. In the context of ocular diseases, salivary exosomes have been under-utilized, thus creating an enormous gap in the literature. The current review discusses the state of exosomes research on systemic and ocular diseases and highlights the role and potential of salivary exosomes as future ocular therapeutic vehicles.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Detection of anti-desmoglein antibodies in oral lichen planus: What do we know so far

Oral lichen planus (OLP) is an inflammatory disease of the oral mucosa. Clinically, two main subsets are described, namely non-erosive and erosive OLP. While non-erosive OLP is usually responsive to local therapies, erosive OLP is often refractory also to systemic therapies and extremely reduces the quality of life of the patients. Furthermore, in some erosive OLP cases different autoantibodies have been detected, including anti-desmoglein 1 and 3 autoantibodies, and anti-bullous pemphigoid 180 and 230 autoantibodies. However, their potential role is still not clear. In this paper, we reviewed the literature about the detection of autoantibodies against desmoglein 1 and 3, the main target antigens of pemphigus vulgaris, in patient with OLP, summarizing the more recent insights on this topic.

Desquamative Gingivitis in the Context of Autoimmune Bullous Dermatoses and Lichen Planus-Challenges in the Diagnosis and Treatment

Desquamative gingivitis (DG) is a clinical term that describes erythema, desquamation and erosions of the gingiva, of various etiologies. Although the clinical aspect is not specific for a certain disease, an accurate diagnosis of the underlying disorder is necessary because the disease course, prognosis and treatment vary according to the cause. DG may inflict significant oral discomfort, which is why patients typically present to the dentist for a first consultation, rendering it important for these specialists to be informed about this condition. Our paper aims to review the ethiopatogenesis and diagnostic approach of DG, focusing on the most common underlying disorders (autoimmune bullous dermatoses and lichen planus) and on the management of these patients. Potential etiological agents leading to an inflammatory immune response in the oral mucosa and DG appearance include genetic predisposition, metabolic, neuropsychiatric, infectious factors, medication, dental materials, graft-versus-host reaction and autoimmunity. A thorough anamnesis, a careful clinical examination, paraclinical explorations including histopathological exam and direct immunofluorescence are necessary to formulate an appropriate diagnosis. Proper and prompt management of these patients lead to a better prognosis and improved quality of life, and must include management in the dental office with sanitizing the oral cavity, instructing the patient for rigorous oral hygiene, periodic follow-up for bacterial plaque detection and removal, as well as topical and systemic therapy depending on the underlying disorder, based on treatment algorithms. A multidisciplinary approach for the diagnosis and follow-up of DG in the context of pemphigus vulgaris, bullous pemphigoid, cicatricial pemhigoid or lichen planus is necessary, including consultations with dermatologists, oral medicine specialists and dentists.

Characteristics of Oral Mucosal Lesions and Their Association With Socioeconomic Status and Systemic Health: A Cross-Sectional Study of Consecutively Collected Oral Medicine Clinic Data in a Remote Rural Area of China

Objectives

Epidemiological data of oral mucosal lesions (OMLs) are required to develop practical oral care policies. However, limited data are available for rural areas in China. We aimed to estimate the spectrum and frequency of OMLs and to identify their associated socioeconomic status (SES) and systemic health in a remote rural area in Yunnan, China.

Methods

We screened patients for OMLs in an oral medicine clinic in rural Yunnan, China, from August 2020 to February 2021. OMLs were documented. SES, including the highest education level achieved and the previous month's household income, as well as the patient's systemic health, including a history of smoking, alcohol use, and chronic disease, were obtained from the Medical History/Health Questionnaire Form and patient medical records.

Results

A total of 146 patients were found to have OMLs. The most frequent OML was aphthous ulcer (n = 41, 28.1%), followed by burning mouth syndrome (BMS) (n = 16, 11.0%), viral ulcer (n = 14, 9.6%), and oral lichen planus (OLP) (n = 9, 6.2%). In these patients, the most common chronic diseases were sleep apnea (n = 35, 24.0%), hypertension (n = 23, 15.8%), bronchitis (n = 16, 11.0%), reflux (including gastroesophageal reflux disease) (n = 12, 8.2%), and arthritis (n = 11, 7.5%). On adjusted regression, the patients without chronic diseases had a lower risk of BMS than those with chronic diseases [odds ratio (OR), 0.2; 95% confidence interval (CI), 0.03–0.9]. Age was an independent protective factor for viral ulcers (OR, 1.0; 95% CI, 0.9–1.0). Patients with low-income levels had a lower risk of OLP than those with high-income levels (OR, 0.2; 95% CI, 0.05–0.9).

Conclusions

Our oral medicine clinic data in remote Yunnan, China, showed the most frequent OML was aphthous ulcer, which was followed by BMS, viral ulcer, and OLP. Oral care policies should be prioritized among patients with aphthous ulcer. Preventive strategy of BMS should be targeted to people with chronic disease for health equalities. Therefore, an individualized strategy for interventions of OMLs might be optimal, based on the specific epidemiologic characteristics in rural settings.

Oral Lichen Planus: Associations Between Histomorphometric Characteristics and White and Red Lesions

Histomorphometry seems to provide more rigid quantitative elements for histological analysis and to bring less subjectivity to the diagnosis of oral lichen planus lesions (OLP). This study aimed to verify the association between white and red lesions and histomorphometric characteristics of OLP lesions. This retrospective cross-sectional study assessed 48 hematoxylin- and eosin-stained histological sections from incisional biopsies obtained from OLP cases. A single previously calibrated evaluator performed the light microscopy analyses to evaluate morphological and morphometric parameters. Analyses of associations among variables were performed using the Fisher's exact test. Morphometric variables were assessed using the Mann-Whitney non-parametric test. Comparisons among the three groups (age range) were performed using the Kruskal-Wallis test. In this study, 81.2% of the participants were women aged < 50 years. Keratosis, acanthosis, and inflammatory infiltrates were noted in 10.4, 10.4, and 37.5% of moderate/severe cases, respectively. Inflammatory infiltrate (52.1%), papillary projections (54.2%), saw teeth (12.5%), basal layer degeneration (39.6%), and Civatte bodies (68.8%) were also observed. There was no significant association between lesion type and clinicopathological variables (p > 0.05) or between lesion type and histological (p > 0.05) and morphometric variables (p > 0.05). Furthermore, the morphometric variables analyzed did not differ between white and red lesions (p > 0.05) or in their associations with clinicopathological variables (p > 0.05). The results of this investigation showed no associations between white and red OLP lesions and the histomorphometric characteristics evaluated.

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.

Challenges and pitfalls between lichen planus pemphigoides and bullous lichen planus

Lichen planus pemphigoides (LPP) and bullous lichen planus (BLP) are rare dermatoses, which are characterised by blisters and lichenoid lesions. Their clinical presentation is heterogenous, displaying overlapping features or mimicking other dermatological diseases. Therefore, diagnosis can often be challenging, requiring a thorough dermatological examination along with distinctive histological and immunopathological characteristics. Lichenoid degeneration of the basal epidermis exposes various antigens of the dermal-epidermal junction in LPP, resulting in the breakdown of immune tolerance, hence, the production of autoantibodies against type XVII collagen. Conversely, no pathogenic autoantibodies are detected in BLP. However, some cases of mucosal lichen planus might display immunopathological features suggestive of autoimmune blistering diseases. Therefore, a better understanding of the pathophysiology of these two distinct dermatoses is imperative. The aim of this review was to provide a summary of the current knowledge on the clinical hallmarks, diagnosis and available therapeutic options in LPP and BLP.

The Tipped Balance of ILC1/ILC2 in Peripheral Blood of Oral Lichen Planus Is Related to Inflammatory Cytokines

Oral lichen planus (OLP) is an immune-inflammatory disease mediated by T cells. Innate lymphoid cells (ILCs) constitute a novel family of immune cells that initially originate from common innate lymphoid progenitors. Termed “T cells counterparts,” ILCs play a prominent role in inflammatory-immune diseases. However, the characterization of ILCs and their related induced factors were unclear in OLP. In the present study, the phenotypic characteristics of ILCs and their correlation with inflammatory cytokines were explored in the peripheral blood of OLP patients and healthy controls. We found that the proportion of total ILCs was expanded in OLP and was positively correlated with disease severity. The highly skewed distribution of ILC subpopulations was notable in OLP. Specifically, the frequency of ILC1s was significantly increased, while that of ILC2s was significantly reduced in total ILCs of OLP, resulting in the markedly elevated ILC1/ILC2 ratio in OLP. Correspondingly, ILCs in OLP displayed high expression of T-bet but low expression of GATA3. In addition, the IFN-γ expression level was elevated in ILC1s, whereas the IL-4 expression level was decreased in ILC2s. Moreover, ILC-associated activators IL-12, IL-18, and IL-1β were upregulated in OLP plasma, with IL-12 and IL-1β both positively correlated with the ILC1/ILC2 ratio. Further in vitro stimulation tests indicated that OLP plasma remarkedly increased the ILC1/ILC2 ratio, especially that IL-12 and IL-1β tipped the balance between ILC1s and ILC2s toward ILC1s in total ILCs. Overall, elevated levels of IL-12 and IL-1β might act as environmental cues in tipping the balance of ILC1/ILC2 in the peripheral blood of OLP, contributing to the immune dysregulation in OLP.

Salivary cytokine profile in patients with oral lichen planus

Background/purpose

Oral lichen planus (OLP) is a chronic inflammatory lesion of oral mucosal, and its pathogenesis involves immune cell-mediated aberrances. However, the findings conflict with each other. This research aimed to comprehensively detect the salivary cytokine profile of patients with OLP.

Materials and methods

The cohort included 60 OLP patients (30 reticular and 30 erosive), and 30 healthy controls, matched in age and sex. Human Cytokine/Chemokine Magnetic Bead Panel Kit (HCYTMAG-60K-PX41) was used to detect salivary inflammation-related cytokines. Rank sum test, group t-test, and ANOVA were used for data analysis in different groups. Moreover, Spearman's rank correlation analysis was used to analyze the correlation between salivary cytokine levels and OLP lesion severity.

Results

The levels of TNF-α, G-GSF, IL-1α, IL-1β and IL-8 were statistically significant higher in both erosive and reticular OLP patients than in the healthy group, while the IL-13 level was significantly lower. Particularly, the salivary TNF-α, GM-CSF, MIP-1α, MIP-1β, IL-1β, IL-6 and IL-8 levels were higher in erosive OLP group than other groups. Spearman's rank correlation analysis revealed that the salivary TNF-α, GM-CSF, MIP-1α, MIP-1β, IL-1β and IL-6 levels were positively correlated with OLP lesion severity.

Conclusion

Imbalance of the Th1/Th2-mediated immune response contributes to OLP. Certain salivary cytokines, such as MIP-1α, MIP-1β, GM-CSF, and IL-6, are positively correlated with OLP severity, and they have a high potential as biomarkers to diagnose and predict OLP prognosis.

Association of childhood vaccination with pediatric lichen planus: A systematic review

Lichen planus (LP) is a chronic T-cell-mediated mucocutaneous inflammatory disease, largely recognized in adults. It is uncommon in children, and the literature present still lacks comprehensive understanding mainly due to underreporting of such cases. LP shows atypical clinical features, when seen in children, mainly affecting the flexor aspect of the wrists, legs, and the oral and genital mucosae. It is largely considered an autoimmune response of the body with various etiologic factors. Its association with vaccination is still an interesting field for research. The focus of the present systematic review was to discover the link of vaccine in the pathogenesis of juvenile LP. An electronic search was carried out using MEDLINE by PubMed, Google Scholar, and Web of Science databases. Articles that reported LP in children with prior records for vaccination were selected for the present systematic review. Twenty-three published articles in the English language were included for the quantitative and qualitative syntheses. The demographic data, specific vaccine history, and clinical details of the lesions were recorded. The existing evidence supports that vaccines could play an important role in etiopathogenesis of pediatric LP.

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.

RNA-Seq based transcriptome analysis in oral lichen planus

Objectives

Oral lichen planus (OLP) is a T cell-mediated autoimmune disease recognized as an oral potential malignant disorder (OPMD) with the precise mechanism unknown. This study focused on the transcriptional profiles of OLP to elucidate its potential pathogenesis.

Methods

We conducted RNA sequencing on matched 6 OLP tissues and 6 normal oral mucosal tissues. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and weighted gene co-expression network analysis (WGCNA) were performed on differentially expressed genes (DEGs). We utilized qRT-PCR to validated the top dysregulated genes and hub genes in another 10 pairs of specimens.

Results

A total of 153 DEGs (p-values< 0.05) were detected from RNA-Seq. According to GO and KEGG analysis, the dysregulated genes were mainly related to T cell related pathway and Wnt signaling. Based on the WGCNA analysis, 5 modules with high intramodular connectivity and hub genes in each module were gained.

Conclusions

RNA-Seq and bioinformatic methods offered a valuable understanding of the biological pathways and key genes in the regulation of OLP. The identified DEGs and hub genes categorized into 2 groups including T cell regulation and inflammation and Wnt signaling pathway may serve as potential novel molecular targets for therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-021-00202-z.

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.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Markers associated with malignant transformation of oral lichen planus: A review article

Oral lichen planus (OLP) is one of the autoimmune diseases associated with chronic inflammation that involves several complications including the potential for malignant transformation into oral squamous cell carcinoma. Pathogenesis of OLP are yet to be fully comprehended however, it has been demonstrated that the epithelial cells in OLP lesions are affected by cytotoxic T lymphocytes leading to immunological reactions. Various factors are reported to act as diagnostic markers for predicting and monitoring the cancerous progression. Hence, in this review, we summarize and present the latest studies regarding the predictive markers associated with malignant potential of 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.

Interferon-γ activated T-cell IRGM-autophagy axis in oral lichen planus

Oral lichen planus (OLP) is an inflammatory immune disease featured by dense T-cell infiltrate and basal keratinocytes degeneration. Immunity related GTPase M (IRGM) is vital for the induction of autophagy. Our previous studies have demonstrated aberrant autophagy in OLP, however, the involvement of IRGM-autophagy axis in OLP has not yet been revealed. The expression of IRGM and autophagy activity were evaluated in oral mucosal tissues and peripheral T cells of OLP patients and healthy controls, respectively. We found significant upregulation of IRGM and LC3B in lesions of patients with OLP as compared with healthy donors. IRGM, LC3B and NOD2 levels were also elevated in the peripheral T cells of OLP. Then, knockdown of IRGM after electrotransfection with siRNA resulted in attenuated autophagy, growth inhibition, and apoptosis of T cells. In addition, preincubation with IFN-γ promoted the expression of IRGM mRNA and induced autophagy in T cells. Furthermore, IFN-γ decreased the proliferation and apoptosis of T cells, whereas facilitated the viability of keratinocytes in a co-culture system of activated T cells and keratinocytes. Taken together, activated IRGM-autophagy axis under IFN-γ regulation in T cells might participate in the immunoregulatory mechanism of OLP.

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.

YouTube™ and oral lichen planus: an appraisal of the educational quality of information

The objective of this study was to analyze the quality of videos on oral lichen planus (OLP) available in YouTube™. A cross-sectional analytical study was conducted by searching the video sharing platform YouTube™. Videos aimed at clarifying the etiological and clinical characteristics, diagnostic criteria, treatment, and prognosis of OLP were included. A total of 481 videos were retrieved and 37 were included in the study according to the selection criteria established. Most of the videos evaluated (86.5%; n = 32) were produced by independent users. The average reliability was 1.8 and quality assessment classified only three videos (8.1%) as having good/excellent quality. A significant correlation was observed between the length of the video analyzed and its quality and reliability (p < 0.05), as well as between the reliability and usefulness of the video (p = 0.03). YouTube™ has become a leading source of information for the general population. However, a significant number of these videos have a low quality. Students, professionals, and healthcare providers must be more actively involved in providing clear, accurate, and reliable evidence-based information in an accessible language in order to enable significant improvement in patient care delivery.

T cell-derived exosomes induced macrophage inflammatory protein-1α/β drive the trafficking of CD8+ T cells in oral lichen planus

Oral lichen planus (OLP) is a T cell–mediated chronic inflammatory disease with uncertain aetiology. Exosomes are nanosized particles with biological capacities. Here, we aimed to study the effects of T cell–derived exosomes (T‐exos) on the pathogenesis of OLP and its mechanism. T‐exos were incubated with Jurkat cells for 48 hours, and 26 cytokines in the supernatant were measured by luminex assay. The expression of macrophage inflammatory protein (MIP)‐1α/β was detected using immunohistochemistry and ELISA; that of CCR1/3/5 on peripheral T cells was determined by flow cytometry. Transwell assay was performed to investigate the chemotactic effect of MIP‐1α/β, and cells in the lower chambers were examinated by flow cytometry. As a result, OLP T‐exos elevated the production of MIP‐1α/β, which were highly expressed in OLP tissues and plasma. CCR1/5 were markedly expressed on OLP peripheral T cells, and the majority of CCR1/5⁺ T cells were CD8⁺ T cells. Besides, MIP‐1α/β promoted the migration of OLP mononuclear cells, while inhibiting CCR1/5 significantly decreased the trafficking of mononuclear cells, especially that of CD8⁺ T cells. Conclusively, OLP T‐exos‐induced MIP‐1α/β may drive the trafficking of CD8⁺ T cells after binding with CCR1/5 in OLP, contributing to the development of OLP.

Correlation of VEGF and MMP-2 levels in oral lichen planus: An in vivo immunohistochemical study

Background

This study aimed to investigate the relation between vascular endothelial growth factors (VEGF) and matrix metalloproteinase-2 (MMP-2) in different oral lichen planus (OLP) forms compared to control patients.

Methods

Biopsies from 60 patients were selected and equally distributed as follows: reticular/popular OLP (R/PLP), atrophic/erosive OLP (A/ELP) patients, healthy subjects (Control). All biopsies were immune-histochemical stained and statistically analyzed for VEGF and MMP-2 expression.

Results

Immune-expression of VEGF was significant between OLP and control (P-value <0.001). OLP showed a higher epithelial expression of VEGF in A/ELP compared to R/PLP (15.19 ± 2.53). In connective tissue (CT), R/PLP showed a higher VEGF expression (11.57 ± 2.32) compared to A/ELP (9.87 ± 2.48); (p < 0.001), with no significant difference (P-value ≥ 0.05). A significant epithelial expression of MMP-2 was seen in A/ELP compared to R/PLP (21.32 ± 7.08). R/PLP showed a higher expression of MMP-2 (20.45 ± 6.28) in CT compared to A/ELP group (17.66 ± 6.94), with a non-significant difference (P-value = 1.000). In A/ELP, a positive correlation between VEGF and MMP-2 was detected in CT, r = 0.761, with a weak correlation was noticed in epithelium r = 0.163. A negative correlation was noted between VEGF and MMP-2 in R/PLP in CT, r = -0.368, with a moderate positive correlation in epithelium, r = 0.655.

Conclusion

MMP-2 and VEGF protein profiles support a role in the pathogenesis of OLP. Based the MMP-2 and VEGF findings in the A/ELP group, this pathway may have a role in the malignant transformation of these lesions. Both observations invite further study.

In silico evaluation of drugs used in treatment of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic T cell-mediated, immunological, mucocutaneous disease with a number of genes and inflammatory mediators implicated in its pathogenesis. Heart shock protein 70 and the proinflammatory mediator TNFα have been predominantly involved in the etiopathogenesis of oral lichen planus.

METHODS

In this study, the action of 27 commonly used drugs for treating OLP at HSP70 and TNFα were evaluated by molecular docking using Maestro Schrodinger version 10.1. X-ray crystallographic structures of the target proteins, that is, Heat Shock Protein 70 (PDB Code: 6FDT) and tumor necrosis factor alpha-1 (PDB Code: 1TNF) were obtained from Protein Data Bank (PDB). The structures of the ligands (27 drugs) were obtained from PubChem in.sdf format. Using Ligprep, pre-processing of the ligands was done. Extra-precision docking was performed with the prepared protein and the ligands.

RESULTS

With respect to HSP70, the highest dock score (-4.768) and glide score (-4.818) were seen with hydroxychloroquine (HCQ), followed by epigallocatechin gallate (green tea), methotrexate, and curcumin. The highest dock (-9.525) and glide score (-9.584) in TNFα were seen in with epigallocatechin gallate, followed by HCQ, dapsone, and methotrexate.

CONCLUSION

The results of the study tend to explain the clinical use of HCQ in recalcitrant and severe cases, as well as the anti-inflammatory property of epigallocatechin gallate. The results of the study open ventures for exploring the in silico behavior of drugs for effective pathological management.

Emerging functions and clinical applications of exosomes in human oral diseases

Exosomes are cell-derived membranous vesicles of endosomal origin secreted by all type of cells and present in various body fluids. Exosomes are enriched in peptides, lipids, and nucleic acids, emerging as vital modulators in intercellular communication. Exosomes are increasingly being evaluated as biomarkers for diagnosis and prognosis of diseases, because the constituents of exosomes could be reprogrammed depending on the states of diseases. These features also make exosomes a research hotspot in oral diseases in recent years. In this review, we outlined the characteristics of exosomes, focused on the differential expressions and altered biological functions of exosomes in oral diseases, including oral squamous cell carcinoma, oral leukoplakia, periodontitis, primary Sjögren’s syndrome, oral lichen planus, as well as hand foot and mouth disease. Besides, accumulated evidence documents that it is implementable to consider the natural nanostructured exosomes as a new strategy for disease treatment. Herein, we highlighted the therapeutic potential of exosomes in oral tissue regeneration, oncotherapy, wound healing, and their superiority as therapeutic drug delivery vehicles.

Combination Therapy with 1% Nanocurcumin Gel and 0.1% Triamcinolone Acetonide Mouth Rinse for Oral Lichen Planus: A Randomized Double-Blind Placebo Controlled Clinical Trial

Objectives

This study aimed to evaluate the efficacy of a combination of 1% nanocurcumin gel with 0.1% triamcinolone acetonide mouth rinse for oral lichen planus (OLP).

Materials and Methods

This double-blind randomized clinical trial was conducted on 31 patients with erosive or ulcerative OLP. All patients received 0.1% triamcinolone mouth rinse and were then randomly divided into two groups for combination therapy with (I) %1 nanocurcumin gel or (II) placebo gel. The reticular-erosive-ulcerative (REU) score was calculated at baseline and at two and four weeks after the intervention. The changes in the mean REU score and the efficacy index were calculated to determine the level of improvement after two and four weeks. Data were analyzed using independent t-test, repeated measures ANCOVA, Mann–Whitney test, and chi-square test. P < 0.05 was considered statistically significant.

Results

There were 14 patients in the nanocurcumin and 17 patients in the placebo group. A significantly higher decrease in the mean REU score was observed in the nanocurcumin compared with the placebo group (P < 0.001). The efficacy index was significantly higher in the nanocurcumin group (P < 0.001).

Conclusion

Application of 1% nanocurcumin in combination with 0.1% triamcinolone acetonide can serve as an effective treatment strategy to enhance the level of improvement of lesions compared with the use of triamcinolone acetonide alone.

Aquaporin3 (AQP3) expression in oral epithelium in oral lichen planus

Lichen Planus is an autoimmune disease of skin and mucous membranes, including oral mucosa and genital organs, with the potential to undergo a malignant transformation. Xerostomia and the salivary gland hypofunction are common manifestations and complications in oral lichen planus (OLP), whose exact cause has not been well defined yet. Aquaporins (AQP) are a family of membrane channel cell proteins which play an important role in the intercellular water permeability. This study for the first time compares the expression of the aquaporin-3 (AQP3) gene in oral tissues of a group of OLP patients and a control group. In this study, 30 OLP patients and 30 healthy individuals were selected. The expression of AQP3 gene was measured using Real-Time PCR method. The expression of the gene in the OLP patients was more than the control group. It could be argued that decreased salivation increases the level of expression of the AQP3 gene in an effort to compensate for this deficiency and prevent the onset of xerostomia (compensatory up-regulation).

[Development of precancerous lesions of oral mucous membrane diseases and oral cancer animal models]

Precancerous lesions of oral mucous membrane diseases and oral cancer are common diseases in developing countries, especially in South Asia. However, the cancerous mechanism remains unclear, and no efficient treatment and prognosis measure are currently available. Thus, precancerous lesions of the oral mucosa and oral cancer animal models must be identified to further understand their function. In this paper, we systematically review the development of oral mucosal precancerous lesions and oral cancer animal models by referring to related research.

HIF1α/PLD2 axis linked to glycolysis induces T-cell immunity in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a common T-cell-mediated immunological disease. Hypoxia-inducible factor 1 alpha (HIF1α) plays an integral role in the glycolytic metabolism that facilitates immune functions from boosting cellular proliferative capacity to driving T-cell differentiation. In general, phospholipase D2 (PLD2) is required for HIF1α regulation. However, the involvement of HIF1α and PLD2 in dysfunctional T-cell immunity of OLP remains elusive.

METHODS

HIF1α and PLD2 expression in OLP lesions were determined by qRT-PCR, immunohistochemistry and immunofluorescence staining, and correlation analysis was carried out between their expressions. HIF1α or PLD2 silencing in T cells was performed to investigate the glycolytic alteration. Then their involvement in T-cell immunobiology was evaluated by detecting cell proliferation, cell cycle, apoptosis, and effector subsets differentiation. Additionally, the modulation of HIF1α on PLD2 expression and the engagement of mTOR in this process were explored.

RESULTS

HIF1α and PLD2 protein were highly expressed in OLP lesions and they were both observed in large numbers of local CD3⁺ T cells in OLP. Besides, HIF1α expression was positively correlated with PLD2 expression in OLP. Both HIF1α and PLD2 promoted T-cell proliferation and pro-inflammatory phenotype differentiation, which was associated with the upregulation of glycolysis mediated by HIF1α or PLD2. Moreover, HIF1α induced PLD2 expression in an mTOR-independent way.

CONCLUSIONS

HIF1α/PLD2 axis was supposed to be critical regulatory signaling involved in the T-cell immunity of OLP.

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.

The mTOR-glycolytic pathway promotes T-cell immunobiology in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory mucosal disease. T cells require rapid metabolic reprogramming for their effector functions after activation by immunologic stimuli. The mammalian target of rapamycin (mTOR) is a central player in the metabolic reprogramming and immune responses of T cells. The present study investigated the role of mTOR in the immunometabolism of OLP. mTOR and its direct target eukaryotic initiation factor 4E binding protein 1 (4E-BP1) were highly phosphorylated in peripheral T cells of OLP patients. Rapamycin-mediated blockage of mTOR activation restrained both T-cell proliferation and DNA synthesis, promoted apoptosis, and decreased Th1/Th2 and Th17/Treg ratios. Dual blockage of mTOR and phosphatidylinositol 3-kinase (PI3K) exerted stronger inhibition on T-cell immunobiology than selective repression of PI3K alone. Rapamycin also blocked the glycolytic pathway in T cells. Moreover, glucose-induced activation of mTOR-glycolytic pathway increased T-cell proliferation, DNA synthesis, and the Th17/Treg ratio, and decreased T-cell apoptosis. In contrast, inhibition of glycolysis by 2-Deoxy-d-glucose (2-DG) yielded the opposite effects on T-cell immunobiology by blocking the mTOR pathway. In conclusion, enhanced activation of the mTOR-glycolytic pathway promoted T-cell immunobiology, suggesting that dysregulation of immunometabolism might be associated with T-cell dysfunction in OLP.

A Comparative Evaluation on the Effect of Oral Zinc 50 mg with or without 0.1% Triamcinolone Orabase on Oral Lichen Planus

BACKGROUND

Lichen planus is a T-cell-mediated autoimmune disease, in which CD8+ T-cells releases the cytokines such as tumor necrosis factor-alpha and interleukin-12 disrupting basement membrane integrity. Treatment modalities were directed toward the relief in signs and symptoms and preventing recurrences. Zinc activates caspase-3 and DNA fragmentation, resulting in the apoptosis of keratinocytes. Prevention of matrix metalloproteinases1 (MMP1) activation, inhibits the Tcell accumulation in oral lichen planus (OLP) and by inhibiting MMP9, prevents the cleavage of collagen resulting in maintaining the integrity of the basement membrane.

OBJECTIVES

The main objective of the study is to compare the efficacy of oral zinc 50 mg and 0.1% triamcinolone Orabase with 0.1% triamcinolone Orabase alone on the healing process of symptomatic OLP.

MATERIALS AND METHODS

A total of forty participants were randomly categorized into two groups: Group A and Group B with 20 patients with OLP and having symptoms of burning sensation. Group A patients had received 0.1% triamcinolone Orabase twice daily application. Group B patients had provided with oral zinc 50 mg and 0.1% triamcinolone Orabase twice daily for 8 weeks. The follow-up period for both the groups was 6 months. Lesional size was measured by Thongprasom scale and burning sensation was assessed by visual analog scale at each visit till the cessation of treatment.

RESULTS

There was decrease in the burning sensation and lesional size from the first visit to follow-up period which was statistically significant in both groups (P = 0.000).

CONCLUSION

Oral zinc therapy was adjunctive in reducing the burning sensation and lesional size in the symptomatic OLP.

Cytokines Levels and Salivary Microbiome Play A Potential Role in Oral Lichen Planus Diagnosis

Oral lichen planus (OLP) is a chronic Th1-mediated inflammatory mucocutaneous disease of the skin and oral mucosa that can have various clinical presentations. Lesions are usually bilateral and often painful. While cutaneous Lichen Planus (LP) lesions are self-limiting, the oral lesions are chronic and rarely remissive. The diagnosis of oral lichen planus (OLP) is often challenging, and confirmation by histopathological criterion is generally advised. The aim of our study was to identify the cytokines present in OLP-suggestive lesions and in non-specific inflammatory lesions (NSIL) used as controls. Moreover, assess cytokines protein levels and oral microbiota composition in whole saliva samples. Histopathological analysis, immunohistochemistry and gene expression were used as techniques to analyze the oral mucosal tissue samples. ELISA was conducted to analyze salivary cytokine levels and 16S rRNA sequencing was used to determine the salivary microbiome. As a result we observed larger number of infiltrated lymphocytes (p = 0.025), as well, more T CD4 lymphocytes in the epithelial tissue (p = 0.006) in OLP samples compared to NSIL. In addition, the OLP samples displayed more apoptotic cells compared to NSIL (p = 0.047). Regarding the cytokine analysis, IFN-γ and IL-33 were more expressed in OLP lesions than in NSIL samples (p < 0.001; p = 0.026). Furthermore, our results demonstrated higher levels of IFN-γ protein expression in the saliva of OLP group compared to controls (p = 0.0156). We also observed noted differences in the oral microbiota composition between OLP and NSIL saliva samples. In conclusion, OLP lesions presented larger numbers of apoptotic and inflammatory cells, higher levels of IFN-γ and IL-33 compared to NSIL, and these lesions also differ regarding oral microbiota composition. These results are consistent with the Th-1-mediated chronic inflammation nature of oral lichen planus investigated lesions and displayed unique features that could be used as a diagnostic tool.

Reactive Carbonyl Species as Potential Pro-Oxidant Factors Involved in Lichen Planus Pathogenesis

The constant generation of reactive carbonyl species (RCSs) by lipid peroxidation during aerobic metabolism denotes their involvement in cell homeostasis. Skin represents the largest organ of the body that is exposed to lipid peroxidation. Previous studies have suggested the involvement of oxidative stress in the development of lichen planus (LP), a chronic inflammatory skin condition with a complex pathogenesis. The aim of our study is to investigate a panel of pro-oxidants (4-hydroxy-nonenal (4-HNE), thiobarbituric acid reactive substances (TBARS), and malondialdehyde (MDA)), the total antioxidant status (TAS), and thiol-disulfide homeostasis parameters (TDHP), including total thiol (TT), native thiol (NT), disulfides (DS), DS/NT ratio, DS/TT ratio, and NT/TT ratio. The comparative determinations of serum levels of 4-HNE, TBARS, and MDA in patients with LP (n = 31) and controls (n = 26) show significant differences between the two groups (4-HNE: 7.81 ± 1.96 µg/mL vs. 6.15 ± 1.17 µg/mL, p < 0.05, TBARS: 4.23 ± 0.59 µmol/L vs. 1.99 ± 0.23 µmol/L, p < 0.05, MDA: 32.3 ± 6.26 ng/mL vs. 21.26 ± 2.36 ng/mL). The serum levels of TAS are lower in LP patients compared to the control group (269.83 ± 42.63 µmol/L vs. 316.46 ± 28.76 µmol/L, p < 0.05). The serum levels of TDHP are altered in LP patients compared to controls (NT: 388.10 ± 11.32 µmol/L vs. 406.85 ± 9.32., TT: 430.23 ± 9.93 µmol/L vs. 445.88 ± 9.01 µmol/L, DS: 21.06 ± 1.76 µmol/L vs. 19.52 ± 0.77µmol/L). Furthermore, a negative association between pro-oxidants and TAS is identified (4-HNE - rho = -0.83, p < 0.01, TBARS - rho = -0.63, p < 0.01, and MDA - rho = -0.69, p < 0.01). Understanding the mechanisms by which bioactive aldehydes exert their biological effects on the skin could help define effective therapeutical strategies to counteract the cytotoxic effects of these reactive metabolic intermediates.

Evaluation of depression, anxiety and stress levels in patients with oral lichen planus

The pathogenesis of oral lichen planus (OLP) remains to be fully elucidated; however, certain psychoneurological factors may influence the onset and exacerbation of OLP. The aim of the present study is to evaluate the intensity of negative emotions in patients with OLP. A cross-sectional, questionnaire-based study was performed. The sample consisted of 52 subjects, comprising 26 patients with OLP (OLP group) and 26 controls (CTRL group). The Depression Anxiety Stress Scale 21 (DASS-21) was used for psychometric evaluation. The patients were also asked about their attitude toward the disease, treatment, and interference of the disease on daily life. The mean level of depression was 12.54 ± 6.6 in the OLP group and 7.69 ± 5.22 in the CTRL group (P = 0.006). The mean level of anxiety was 11.15 ± 7.95 in the OLP group and 6.62 ± 4.86 in the CTRL group (P = 0.018). The mean stress levels were 8.69 ± 7.06 and 3.85 ± 3.18 in the OLP and CTRL groups, respectively (P = 0.003). Severe and very severe scores of depression and very severe scores of anxiety and stress were present in the OLP group, whereas these emotions were normal in the majority of controls. Depression, stress, and anxiety may be involved in the pathogenesis and course of OLP.

Comparison of serum lipid parameters between patients with classic cutaneous lichen planus and oral lichen planus

OBJECTIVES

Previous studies have shown that patients with lichen planus (LP) have an increased occurrence of inflammation-related dyslipidemia. Although classic cutaneous LP (CCLP) and oral LP (OLP) are basically known as the different subtypes of the same disease sharing the common histopathological features, they actually have significant differences both in the clinical behavior and in the molecular inflammatory pathogenesis. We aimed to compare the lipid profile of patients with CCLP and OLP.

MATERIALS AND METHODS

This study included 120 patients, 30 with isolated CCLP, 30 with isolated OLP, 30 with CCLP + OLP, and 30 controls consecutively admitted to the outpatient clinics of Dermatology Department of Dokuz Eylul University Hospital, Izmir, Turkey.

RESULTS

Triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) values, TC/high-density lipoprotein cholesterol (HDL-C), and LDL-C/HDL-C atherogenic indexes were significantly higher, and HDL-C values were significantly lower in all LP subtypes compared with the controls. Among LP subtypes, although the differences were not statistically significant, TG, TC, and LDL-C values were markedly higher in OLP and OLP + CCLP patients compared with CCLP patients. OLP and CCLP + OLP patients also showed significantly higher TC/HDL-C and LDL-C/HDL-C atherogenic indexes compared with CCLP patients.

CONCLUSIONS

Patients with OLP have a more impaired lipid metabolism and significantly higher atherogenic indexes compared with patients with CCLP. The differences in the molecular inflammatory pathways between OLP and CCLP and the longer disease duration of OLP leading to long-lasting inflammation may elucidate this distinction.

CLINICAL RELEVANCE

We recommend to pay close attention to the early recognition of coexisting atherogenic dyslipidemia and to apply the early protective measures against the development of cardiovascular disease in OLP patients.

Lichen planus of lip - Report of a rare case with review of literature

Lichen planus (LP) is a potentially malignant disorder with an immune-mediated etiopathogenesis. The condition frequently affects the skin, oral mucosa, skin appendages, and other mucous membranes. Oral lesions usually precede the onset of skin lesions and in majority of cases may only be presenting symptom. Isolated LP of the lip is rarely encountered in the clinical practice and is usually seen along with skin/other mucous membrane involvement. The clinical appearance poses diagnostic dilemmas and is often misinterpreted. This case report aims to highlight an interesting case of LP of the lower lip in a 50-year-old male patient. The patient presented with a diffuse erosive lesion on the lower lip bordered by white radiating striae on its inner aspect. Histopathological and immunofluorescent studies confirmed LP of the lip. Topical corticosteroids and Vaseline lip therapy were prescribed to the patient. There was considerable healing in the lip lesion during the follow-up period. However, recurrence was noted in the left buccal mucosa.

Zinc Therapy in Treatment of Symptomatic Oral Lichen Planus

Lichen planus is a chronic inflammatory disease, which involves skin, mucous membrane, and nails. Prevalence of oral lichen planus varies between 0.5% and 2.6% of adult population worldwide with overall female preponderance. It is considered as a potentially malignant disorder with rate of transformation to oral cancer varying between 0.5% and 2%. Oral lichen planus may either be unilateral or bilateral, or may involve multiple sites. Although the exact etio-pathogenesis of this condition is unknown, it is believed that stress, use of medications, dental fillings, genetics, immunity, and hypersensitivity reactions may contribute to its pathogenesis. It is a T-cell-mediated autoimmune disorder in which CD8+ T cells are involved which release various cytokines such as tumor necrosis factor-α and interleuking-12 leading to disruption of basement membrane integrity. Zinc activates caspase-3 and DNA fragmentation, resulting in the apoptosis of keratinocytes. By prevention of matrix metalloproteinase (MMP)-1 activation, it inhibits T-cell accumulation in oral lichen planus, and by inhibiting MMP-9 it prevents cleavage of collagen IV resulting in maintaining the integrity of the basement membrane. The present case series describes the use of oral zinc acetate (50 mg) in patients having symptomatic oral lichen planus with favorable outcome in terms of size of lesion and global index score.

Oral lichen-planus-associated fibroblasts acquire myofibroblast characteristics and secrete pro-inflammatory cytokines in response to Porphyromonas gingivalis lipopolysaccharide stimulation

Background

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease in which comprehensive inflammation-related cytokines are involved. These cytokines are commonly produced by immune cells and specific nonimmune cells including keratinocytes, endothelial cells and fibroblasts. This raises the question of whether fibroblasts in OLP lesions contribute to the inflammatory process upon inflammatory simulation.

Methods

Primary cultured Oral lichen-planus-associated fibroblasts (OLP AFs, n = 5) and normal buccal mucosal fibroblasts (NFs, n = 5) were examined by immunohistochemistry, Western blotting and reverse transcription-polymerase chain reactions (RT-PCR). Various inflammatory mediators were evaluated with a multiplex assay. Differences among groups were assessed using a Student’s test or repeated measures one-way ANOVA, as appropriate.

Results

OLP AFs express significantly higher levels of α-smooth muscle actin (α-SMA) than NFs, indicating the presence of myofibroblasts. Myofibroblasts secrete Interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) in response to Porphyromonas gingivalis lipopolysaccharide (pg. LPS).

Conclusion

OLP AFs demonstrated α-SMA expression and secreted pro-inflammatory cytokines in response to pg. LPS stimulation.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0656-6) contains supplementary material, which is available to authorized users.