Oral lichen planus and related lesions. What should we accept based on the available evidence?

Recent new terminologies have been proposed for lesions in the sphere of oral lichen planus (OLP) that theoretically present unique aetiological, clinical, prognostic or management characteristics different from those of the so-called typical forms of OLP. We aimed to critically analyse what concepts and terminologies related to OLP should we accept based on the available evidence. A review of the literature was carried out in order to critically analyse the concepts and terminologies related to OLP. New concepts and terminologies include oral lichenoid lesions; contact lichenoid reactions, drug lichenoid reactions or those in the context of graft-versus-host disease; chronic ulcerative stomatitis; lichen planus pemphigoid; and some lesions that are difficult to categorise, such as OLP with features of proliferative verrucous leukoplakia and lichenoid lesions of the upper labial mucosa. A multidisciplinary, multicontinent working group has recently published a guideline with recommendations for modifying definitions and terminologies associated with a disease, among which a reasoned, evidence-based justification for the proposed change is considered essential. An in-depth analysis of the newly proposed terms for OLP-related lesions shows that many of them are not justified. In this paper, we set out our position on the basis of the existing evidence on the appropriateness of the use of these new terms.

Hypertension in oral lichen planus: A systematic review and meta-analysis

OBJECTIVES

To perform a systematic review and meta-analysis in order to qualitatively and quantitatively evaluate the prevalence and magnitude of the association of hypertension in patients with oral lichen planus (OLP).

METHODS

MEDLINE, Embase, Scopus, and Web of Science databases were searched for studies published before May 2022, not restricted by publication language or date. The methodological quality and risk of bias of primary-level studies were critically assessed. Meta-analyses were performed, as well as meta-regression, stratified, sensitivity and small-study effects analyses, a Galbraith (radial) plot, and trial sequential analysis. Quality of evidence was evaluated using GRADE system.

RESULTS

104 studies, including 16,587 patients, met the inclusion criteria. The results show that patients who suffer from OLP have a high prevalence of hypertension (PP = 24.17%, 95% CI = 21.45-27.00), with a low quality of evidence. A significant association between hypertension and oral lichen planus was also reported (OR = 1.28, 95% CI = 1.01-1.63, p = 0.04), showing a moderate quality of evidence.

CONCLUSIONS

Patients with OLP could be at an increased risk of suffering from hypertension which is probably due to multiple factors. Healthcare practitioners involved in OLP management should be aware of this comorbidity in order to apply suitable measures and make referrals if hypertension is suspected, although further research is needed.

Mechanism of Huashi Xingyu Qingre recipe in treating oral lichen planus based on network pharmacology and clinical trial verification

OBJECTIVE

To identify the main active components and targets of Huashi Xingyu Qingre recipe (, HXQR) and to investigate its mechanism in the treatment of oral lichen planus (OLP).

METHODS

The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform was searched to identify the active ingredients and corresponding targets of HXQR. Disease genes were obtained from the GeneCards database, and a "drug-disease regulatory network" was constructed using Cytoscape software and PERL programming language. The STRING database was used to build a protein-protein interaction network. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms were analyzed using R software with a Bioconducter plugin. Finally, the results and the efficacy of HXQR in treating OLP were validated in a clinical trial that included enzyme-linked immunosorbent assay (ELISA) testing and observations of the post-treatment changes in clinical symptoms.

RESULTS

HXQR contained 167 active components and 261 targets, with 391 disease targets. The intersection of these two categories in a Venn diagram revealed 57 drug-disease common targets. A compound-target network was constructed and revealed that the six key pharmaceutical ingredients of HXQR were quercetin, luteolin, wogonin, kaempferol, beta-carotene, and baicalein. The protein-protein interaction network mainly involved core proteins such as ALB, interleukin-6, and AKT1. Drug-disease common targets were enriched in 1628 GO terms and 117 KEGG terms, mainly involving inflammatory responses, viral infections, and tumor-related pathways. ELISA testing indicated that HXQR inhibited the tumor necrosis factor (TNF) signaling pathway by reducing the expression of interleukin-6, matrix metalloproteinase-9, and intercellular adhesion molecule-1. The clinical symptoms of the patients with OLP were significantly improved after 8 weeks of treatment with HXQR.

CONCLUSION

HXQR treats OLP by regulating the TNF signaling pathway, resulting in a marked treatment effect with few adverse effects.

Autoimmune disorders in oral lichen planus: systematic review and meta-analysis

OBJECTIVES

The association of OLP with other autoimmune processes points to the possibility that OLP-affected patients are actually developing an autoimmune status that predisposes them to autoaggression against different targets. This systematic review and meta-analysis aims to evaluate the current evidence on the prevalence of autoimmune disorders in patients with OLP and their magnitude of association.

METHODS

We searched PubMed, Embase, Web of Science, Scopus databases for studies published before May 2021, with no limitation in regards to their publication date or language. We evaluated the quality of studies, carried out meta-analyses and performed heterogeneity, subgroups, meta-regression and small-study effects analyses.

RESULTS

Inclusion criteria were met by 153 studies (23,327 patients). Our results indicate the existence of high prevalences and a frequent association between OLP and some autoimmune disorders, especially in regards to thyroid disease (PP=7.96%,95%CI=6.32-9.75; OR=1.99, 95%=1.60-2.49,p<0.001) and diabetes mellitus (PP=9.41%,95%CI=8.16-10.74; OR=1.64, 95%CI=1.34-2.00,p<0.001).

CONCLUSIONS

Our study demonstrates the existence of a comorbidity between autoimmune thyroid diseases an as well as between diabetes mellitus and OLP, respectively. Quality of evidence should be upgraded on other autoimmune diseases (fibromyalgia, gastrointestinal disorders, rheumatic diseases, Sjögren's syndrome, lupus erythematosus and dermatological diseases) for which the current data do not allow us to know whether they are really associated with OLP.

Serum level of estrogen in Iranian patients with oral lichen planus

Background

Oral lichen planus (OLP) is one of the most common diseases in the oral cavity and has a chronic inflammatory nature. The etiology of this disease remains unclear. OLP is more prevalent in women, but to our knowledge, no study yet evaluated estrogen levels in women with OLP.

Objectives

To determine the serum level of estrogen in female patients with OLP.

Methods

This case-control observational study was conducted in patients who were referred to the Department of Oral and Maxillofacial Medicine at the Tehran University of Medical Sciences. After clinical and histopathological confirmation of OLP diagnosis, and according to exclusion and inclusion criteria, 47 women with OLP and 47 healthy women (10 premenopausal and 37 postmenopausal) were included, as case and control groups, respectively. We obtained blood samples (5 mL) from each participant to measure the serum level of 17β-estradiol. Data were analyzed by Spearman rank correlation coefficients and a two-way analysis of variance with Bonferroni post hoc tests.

Results

Serum estrogen level in women with OLP was significantly higher than that in healthy women (P = 0.002), and it was also significantly higher in premenopausal women than postmenopausal women (P < 0.001). The severity of OLP lesions correlated with estrogen level in postmenopausal women (r = 0.650; P < 0.001); in premenopausal women (r = 0.618; P = 0.008), and in all women with OLP (r = 0.535; P < 0.001).

Conclusion

OLP, like other autoimmune diseases, is affected by the serum level of sex hormones such as estrogen.