Non-Coding RNAs as Potential Targets for Diagnosis and Treatment of Oral Lichen Planus: A Narrative Review

Oral lichen planus (OLP) is a chronic inflammatory disease that is characterized by the infiltration of T cells into the oral mucosa, causing the apoptosis of basal keratinocytes. OLP is a multifactorial disease of unknown etiology and is not solely caused by the malfunction of a single key gene but rather by various intracellular and extracellular factors. Non-coding RNAs play a critical role in immunological homeostasis and inflammatory response and are found in all cell types and bodily fluids, and their expression is closely regulated to preserve normal physiologies. The dysregulation of non-coding RNAs may be highly implicated in the onset and progression of diverse inflammatory disorders, including OLP. This narrative review summarizes the role of non-coding RNAs in molecular and cellular changes in the oral epithelium during OLP pathogenesis.

Differential genotypes of TNF-α and IL-10 for immunological diagnosis in discoid lupus erythematosus and oral lichen planus: A narrative review

Discoid lupus erythematosus and oral lichen planus are chronic systemic immune system-mediated diseases with unclear etiology and pathogenesis. The oral mucosa is the common primary site of pathogenesis in both, whereby innate and adaptive immunity and inflammation play crucial roles. The clinical manifestations of discoid lupus erythematosus on the oral mucosa are very similar to those of oral lichen planus; therefore, its oral lesion is classified under oral lichenoid lesions. In practice, the differential diagnosis of discoid lupus erythematosus and oral lichen planus has always relied on the clinical manifestations, with histopathological examination as an auxiliary diagnostic tool. However, the close resemblance of the clinical manifestations and histopathology proves challenging for accurate differential diagnosis and further treatment. In most cases, dentists and pathologists fail to distinguish between the conditions during the early stages of the lesions. It should be noted that both are considered to be precancerous conditions, highlighting the significance of early diagnosis and treatment. In the context of unknown etiology and pathogenesis, we suggest a serological and genetic diagnostic method based on TNF-α and IL-10. These are the two most common cytokines produced by the innate and adaptive immune systems and they play a fundamental role in maintaining immune homeostasis and modulating inflammation. The prominent variability in their expression levels and gene polymorphism typing in different lesions compensates for the low specificity of current conventional diagnostic protocols. This new diagnostic scheme, starting from the immunity and inflammation of the oral mucosa, enables simultaneous comparison of discoid lupus erythematosus and oral lichen planus. With relevant supportive evidence, this information can enhance physicians’ understanding of the two diseases, contribute to precision medicine, and aid in prevention of precancerous conditions.

Oral Lichen Planus Associated With Lichen Planus Pigmentosus and Lichen Sclerosus in Monozygotic Twins

ABSTRACT

Lichen planus (LP) is a mucocutaneous immune-mediated disease of unknown etiology. It is more prevalent in women and usually occurs between the third and sixth decades of life. Oral lesions may or may not be associated with skin and genital lesions. Although the role of genetic factors is still undetermined, reports of LP in more than one family member are not uncommon. However, the occurrence of LP in monozygotic twins is rare. We report a rare case of 42-year-old female monozygotic twins presenting oral LP. This report is even rarer because one of the patients had cutaneous lesions of an unusual variant of LP (LP pigmentosus) and the other had an uncommon association with lichen sclerosus. The etiology and pathogenesis of LP are still uncertain. However, despite being rare, its occurrence in family members and monozygotic twins suggests that genetic factors are involved in its development.

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.

Clinical characteristics and analysis of familial oral lichen planus in eight Chinese families

Oral lichen planus (OLP) is one of the most common oral mucosa diseases; however, familial OLP is uncommon. The present study reported and analyzed patients with familial OLP (n=18) in eight different Chinese families between January 1, 2012 and December 31, 2013. Parameters analyzed include gender, age at diagnosis, lesion distribution and lesion type. The follow-up period for each patient was a minimum of 1 year. In this survey, 18/88 individuals in the eight families were affected. Females were more frequently affected, and the female to male ratio for familial OLP (2.2:1) was higher compared with that previously reported for nonfamilial OLP (1.4:1). The age at diagnosis, lesion distribution and lesion type showed consistency with reports concerning nonfamilial OLP, with the exception of family VI, in which 4/5 children had OLP/LP lesions and were of an early age at diagnosis. There were two families in which three generations had been affected by OLP. In addition, it appeared that patients of the same generation in the same family were of a similar age at diagnosis. No malignant or premalignant lesion was identified in the 18 individuals diagnosed with OLP from the eight families. The present study supports the hypothesis that genetic predisposition may serve a role in the etiology of OLP.

TNF-α, TNF-β and IL-10 gene polymorphism and association with oral lichen planus risk in Saudi patients

Objectives

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease. Cytokines play an important role in the pathogenesis and disease progression of OLP. Various reports have implicated cytokine gene polymorphisms in susceptibility to develop some immune mediated conditions including OLP. The purpose of this study was to investigate the association of tumor necrosis factor (TNF)-α, TNF-β and interleukin (IL)-10 gene polymorphisms with the OLP risk.

Material and Methods

Forty two unrelated patients with OLP and 211 healthy volunteers were genotyped for TNF-α (-308 G/A), TNF-β (+252A/G), IL-10 (-1082G/A), IL-10 (-819C/T), and IL-10 (-592C/A) polymorphisms.

Results

The frequencies of allele A and genotype GA of TNF-α (-308G/A) were significantly higher while allele G and GG genotypes were lower in OLP patients as compared to the controls (P<0.001). The frequency of GA genotype of TNF-β (+252A/G) was significantly higher in patients than in controls while the AA genotype was completely absent in OLP patients. These results indicated that allele A and genotype GA of TNF-α (-308G/A) as well as the GA genotype of TNF-β (+252A/G) polymorphisms are associated with OLP risk. The frequencies of alleles and genotypes of -1082G/A, -819C/T and -592C/A polymorphisms in IL-10 gene did not differ significantly between OLP patients and controls (P>0.05). However, haplotype ATA extracted from 1082G/A, -819C/T, -592C/A polymorphisms of IL-10 were more prevalent in OLP patients when compared to controls indicating its possible association with OLP susceptibility.

Conclusion

It is concluded that TNF-α (-308G/A), TNF-β (+252A/G) and IL-10 (-1082G/A, -819C/T and -592C/A) polymorphisms are associated with the susceptibility of OLP, thus giving additional support for the genetic basis of this disease.

Association of vdr, cyp27b1, cyp24a1 and mthfr gene polymorphisms with oral lichen planus risk

OBJECTIVES

The current study investigated the association between VDR EcoRV (rs4516035), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), CYP27B1 (rs4646536), CYP24A1 (rs2296241), and MTHFR (rs1801133) gene polymorphisms and risk of oral lichen planus (OLP) occurrence.

MATERIALS AND METHODS

The study group consisted of 65 oral lichen planus patients and 100 healthy blood donors in the control group. Single nucleotide polymorphisms were genotyped by real time PCR or PCR-restriction fragment length polymorphism (RFLP) method.

RESULTS

Heterozygous as well as mutated genotype of vitamin D receptor (VDR) FokI (rs2228570) polymorphism was associated with increased oral lichen planus risk in comparison with wild type genotype (odds ratio (OR) = 3.877, p = 0.017, OR = 38.153, p = 0.001, respectively). A significantly decreased OLP risk was observed for heterozygous genotype of rs2296241 polymorphism in CYP24A1 gene compared with the wild type form (OR = 0.314, p = 0.012). VDR gene polymorphisms ApaI and TaqI were in linkage disequilibrium (D' = 0.71, r(2) = 0.22). Identified haplotype AT was associated with decreased OLP risk (OR = 0.592, p = 0.047).

CONCLUSION

Our results highlight the possible important role of VDR FokI (rs2228570) and CYP24A1 rs2296241 gene polymorphisms for oral lichen planus susceptibility.

CLINICAL RELEVANCE

Identification of new molecular biomarkers could potentially contribute to determination of individuals with OLP predisposition.

Chronic desquamative gingivitis in siblings: A report of two cases

Desquamative gingivitis is a gingival response associated with a variety of clinical conditions and characterized by intense erythema, desquamation and ulceration of free and attached gingiva. A variety of diseases such as lichen planus, pemphigus, pemphigoid, dermatitis herpetiformis, linear IgA disease, lupus erythematosus, erythema multiformae manifest clinically as desquamative gingivitis. Of all the disease entities, Lichen Planus is a relatively common disorder affecting the skin and mucous membrane. Very often it has oral manifestations. These lesions of oral lichen planus (OLP) have myriad but distinct morphology. As they mimic other mucocutaneous disorders with regard to clinical appearance, many lesions of oral lichen planus go undiagnosed or are wrongly diagnosed. Reported here are two cases of desquamative gingivitis. One of these was diagnosed as erosive lichen planus based on the symptoms, clinical findings, histologic, and immunofluorescent examination. Further management was done in consultation with a dermatologist.

Oral lichen planus: focus on etiopathogenesis

Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.

Transient liver hypoxia after liver hilus dearterialization

Lichen planus (LP) is a chronic inflammatory disorder that most often affects middle-aged adults. LP can involve the skin or mucous membranes including the oral, vulvovaginal, esophageal, laryngeal, and conjunctival mucosa. It has different variants based on the morphology of the lesions and the site of involvement. The literature suggests that certain presentations of the disease such as esophageal or ophthalmological involvement are underdiagnosed. The burden of the disease is higher in some variants including hypertrophic LP and erosive oral LP, which may have a more chronic pattern. LP can significantly affect the quality of life of patients as well. Drugs or contact allergens can cause lichenoid reactions as the main differential diagnosis of LP. LP is a T-cell mediated immunologic disease but the responsible antigen remains unidentified. In this paper, we review the history, epidemiology, and clinical subtypes of LP. We also review the histopathologic aspects of the disease, differential diagnoses, immunopathogenesis, and the clinical and genetic correlations.