Evaluation of Potential Risk Factors that contribute to Malignant Transformation of Oral Lichen Planus: A Literature Review

Comparison of the effect of the pulsed Er: YAG laser and topical corticosteroid on erosive oral lichen planus: a randomized clinical controlled trial

The formation mechanism of OLP is very complicated, and its treatment has always been a difficult problem. This study was to explore the feasibility of pulsed Er: YAG laser in the treatment of erosive OLP by comparing its effect with that of Triamcinolone Acetonide ointment(TA) of OLP, in order to provide new ideas for the clinical treatment of erosive OLP. Forty patients who were clinically and histopathologically diagnosed as OLP at the Department of Periodontics and Oral Mucosa Disease of Dalian Stomatological Hospital were selected, all lesions accompanied by erosion. The included patients were randomly divided into two groups: Er: YAG group and TA group, with 20 cases in each group. The visual analogue scale (VAS), mean lesion area, clinical sign score, and function score in both groups were evaluated at baseline, 1 week, 2 weeks, 1 month and 3 months after treatment, and the recurrence rate of cured patients in both groups was evaluated at 3 months after treatment. Er: YAG laser was superior to TA in relieving pain at 1 week(1.50 ± 0.946 vs. 2.10 ± 0.912, P < 0.05) and improving function at all stages(P < 0.05). But TA was superior to the pulsed Er: YAG laser in promoting the healing of erosive lesions at 2 weeks(0.07 ± 0.223 vs. 0.31 ± 0.549, P < 0.05). There was no significant difference in recurrence between the two groups(P > 0.05). There is no significant difference between pulsed Er: YAG laser and TA in the treatment of erosive OLP. The use of pulsed Er: YAG laser represents a viable and effective therapeutic option for erosive OLP.

Malignant transformation rate of erosive oral lichen planus: a retrospective study

Oral lichen planus (OLP) is a chronic inflammatory oral condition previously known to have a rate of malignant transformation of around 1%. Additionally, erosive lichen planus, a subtype of lichen planus, which is a known risk factor for malignant transformation, has previously been unquantified in a large cohort of patients. In a single unit observation between 2005 and 2021 we retrospectively assessed 1,920 patients who underwent histological analysis for suspected oral lichen planus, and followed the progression of their disease to assess the rate of malignant transformation. In total, 1.39% of OLP transformed to oral squamous cell carcinoma over an average of 5.8 years. However, we found that the transformation rate of erosive OLP into malignancy was 5.98% with an aggressive clinical pathway. To our knowledge the incidence of erosive OLP has not previously been quantified in a large cohort of patients. This retrospective study sheds light on, and raises warning signs about, the seriousness of this condition.

Comparison of autologous platelet concentrates and topical steroids on oral lichen planus: a systematic review and meta-analysis

BACKGROUND

Oral lichen planus is a chronic and potentially malignant disorder of oral mucosa. Corticosteroids are used as first-line therapy for oral lichen planus patients; however, they have many side effects. Platelet concentrates (platelet-rich plasma and platelet-rich fibrin) are autologous bioactive materials. This systematic review investigated the effects of autologous platelet concentrates compared to topical steroids in treating symptomatic oral lichen planus patients.

MATERIALS AND METHODS

A systematic literature search was performed in PubMed, Web of Science, Scopus, Embase, and Cochrane for randomized controlled trials. Preferred Reporting Items for Systematic Reviews and meta-analysis guidelines were observed for article selection. For the pooling of studies, meta-analysis using Standardized Mean Differences by random effects model was carried out to estimate summary effect sizes for the treatment of oral lichen planus.

RESULTS

A total of six studies, incorporating 109 oral lichen planus patients, were involved. Both treatment modalities showed a statistically significant improvement in the outcome parameters (lesion size, pain score, Thongprasom score) from the baseline to the end of treatment and further to the follow-up visits. There was no significant difference in the pooled estimate SMD of pain decline in patients of the two groups (SMD = 0.17 (95% CI: -0.47 to 0.81); I2 = 63.6%). The SMD of Thongprasom score in patients receiving autologous platelet concentrates was lower than the corticosteroid groups, with no significant effect size (SMD= -2.88 (95% CI: -5.51 to -0.25); I2 = 91.7%). Therefore, there was no statistically significant difference between the autologous platelet concentrates and topical steroids regarding pain and clinical score.

CONCLUSION

Autologous platelet concentrates, and topical steroids decreased the size of lesions, Thongprasom scale, and pain in oral lichen planus patients, but the difference between the two treatments was not statistically significant. Thus, autologous platelet concentrates could be considered as an alternative treatment to topical steroids.

State of the Art in the Diagnosis and Assessment of Oral Malignant and Potentially Malignant Disorders: Present Insights and Future Outlook-An Overview

Oral Potentially Malignant Disorder (OPMD) is a significant concern for clinicians due to the risk of malignant transformation. Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer with a low survival rate, causing over 200,000 new cases globally each year. Despite advancements in diagnosis and treatment, the five-year survival rate for OSCC patients remains under 50%. Early diagnosis can greatly improve the chances of survival. Therefore, understanding the development and transformation of OSCC and developing new diagnostic methods is crucial. The field of oral medicine has been advanced by technological and molecular innovations, leading to the integration of new medical technologies into dental practice. This study aims to outline the potential role of non-invasive imaging techniques and molecular signatures for the early detection of Oral Malignant and Potentially Malignant Disorders.

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.

Investigating the factors proposed in oral lichen planus malignant transformation: A literature review

Background and Aims

Lichen planus is a chronic inflammatory disease that affects about 1% of the world's population. The World Health Organization has included oral lichen planus among potentially malignant disorders. Identification of reliable biomarkers for the diagnosis of malignant transformation may play a unique role in the development of standard screening and improvement of follow-up in patients with oral precancerous lesions. It is currently assumed that the molecular pathways controlling growth, maturation, proliferation, and apoptosis in epithelial cells may play an important role in the process of transformation into malignancy.

Methods

The search was done in PubMed, Scopus, Google Scholar, Embase, and Cochrane databases from 1960 to 2022.

Results

Based on the inclusion criteria, 23 articles were included.

Conclusion

In this review of articles, 34 different biomarkers that have been investigated in studies for the possibility of malignant transformation in OLP have been studied. Among all the risk factors related to malignant transformation, most studies have been done on the role of cytokines and tumor suppressors, in fact, the chronicity of the lesion which is the result of the reaction between the repair and the inflammatory response and the responses accompanied by the secretion of cytokines, may play a major role in the malignant transformation of OLP.

Squamous cell carcinoma in a patient with lichen planus of the oral mucosa

Lichen planus refers to dermatoses with frequent, often isolated, lesions of the oral mucosa. In the presence of rashes only on the oral mucosa, the diagnosis is difficult. At the same time, erosive-ulcerative forms of the disease present the greatest differential diagnostic difficulties. Cases that do not heal for a long time and are not amenable to treatment should be especially alert to the doctor due to the risk of malignancy. The article describes a rare clinical case of squamous cell carcinoma of the oral mucosa in a 52-year-old patient with an erosive-ulcerative form of lichen planus of the oral cavity, characterized by a chronic long-term course, torpidity to therapy and simultaneous damage to the genital mucosa. The presented case emphasizes the importance of a thorough clinical examination, with a histological examination of the biopsy in order to monitor changes in the lesions.

Oral Lichen Planus and Mutated TP53-A Road to Cancer?

The malignant potential of oral lichen planus (OLP) has been discussed and disputed for decades. The lesions are often characterized by strong expression of the TP53 protein in the basal layer of the mucosa. In 2002, we reported the presence of TP53 mutations in nine out of 27 OLP lesions tested. At follow-up in 2009, one case of oral squamous cell cancer (OSCC) had occurred in a different site six years later. In contrast, in another case, TP53 mutation persisted for years without malignant transformation. In a longitudinal study of eight selected patients with OSCC or different pre-malignant lesions, it was concluded that TP53 mutations could occur early or late in the development of OSCC. A follow-up in the present, almost 20 years later, revealed that one further case of OSCC had occurred in a TP53-mutated case of OLP, 21 years after the first sample was taken, again in a different site. With this second case, this small study now points towards a risk of developing OSCC in TP53-mutated OLP lesions. A review of recent literature indicates a growing consensus that OLP should be regarded as a potentially pre-malignant lesion. Several protein markers have been studied, but none proved useful for prediction of malignant progression. The great majority of published studies are retrospective, and it has been suggested that multi-centre prospective studies will be needed to reach a definitive answer on the malignant potential of OLP, and particularly, to identify contributing factors. Screening for TP53 mutations could help to identify the subgroup of OLP patients that is truly at risk of developing oral cancer.

Oral Lichen Planus: risk factors of malignant transformation and follow up. Ten years retrospective study

Background

Oral Lichen Planus (OLP) is an inflammatory chronic disease. Modified World Health Organization (WHO) diagnostic criteria (2003) suggest diagnosing OLP both clinically and histologically. Furthermore, it is known the potential of malignant transformation of OLP, especially those affecting mucosa. Aims of this retrospective study on 100 patients were i) to estimate the timing of transformation of OLP lesions in OSCC in a cohort of patients observed between 2008 and 2018; ii) to assess risk factors of OLP patients diagnosed with OSCC; iii) to analyse forms of OLP evolved in cancer.

Material and Methods

A database of 100 patients diagnosed with OLP was evaluated and clinical, histological features of lesions, habits of patients and systemic diseases were analysed in a follow up ranged between 5 and 10 years.

Results

Mean time of malignant transformation was 31,62± 18,26 months; however, 4 malignant transformations out of 8 occurred about after 4 years of observation. Furthermore, Odds ratios for risk factors showed an association between malignant transformation and location.

Conclusions

More focused attention on follow-up scheduling and designing could be a valuable resource in early diagnosis and cancer prevention in OLP patients.

Key words:Oral Lichen Planus, Oral Cancer, Malignant transformation, risk factors.

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.

Micronutrients Profile in Oral Lichen Planus: a Review Literature

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease. The micronutrients are critical factors in health of oral mucous and proper function of immune system. There have not been any review articles for evaluating trace element levels before and after standard treatments of OLP. The purpose of this study is to provide complete review of the association of micronutrients with OLP. Databases including PubMed, Google Scholar, Scopus, and Embase (Ovid) with keywords of oral lichen planus, OLP, oral disorder, micronutrients, trace element, nutrient element, antioxidant, oxidative stress, malnutrition, and essential trace elements, without time limitation (1900-2019) were searched to collect data on related articles. Total number of 58 original articles including 12 randomized clinical trials, 41 case-control, 4 case reports, and 1 cell line research were reviewed in this study. Lower levels of iron and its associated markers, such as hemoglobin and ferritin, increased levels of TIBC; reduced levels of zinc, calcium, vitamin D, vitamin B12, folic acid, and antioxidants such as vitamins C and E; and increased levels of oxidants and homocysteine, have been reported in OLP patients.

[Lichen planus: fundamentals, clinical variants, histological features, and differential diagnosis]

Lichen planus (LP) is a relatively common inflammatory skin disease in dermatological practice. The typical presentation of LP is usually diagnosed clinically. Less common variants such as LP inversus, atrophic LP, the palmoplantar manifestation or childhood LP may pose diagnostic difficulties so that a biopsy is taken to confirm the diagnosis. Differentiation from LP-like drug eruption may be challenging and biologicals have to be considered as triggers. Etiology and pathogenesis of LP are discussed based on recent literature. Finally, an overview of therapeutic options for different variants of the condition includes most recent approaches to treatment.

Muscarinic cholinergic receptors in minor salivary gland tissues of patients with oral lichen planus: A case-control study

BACKGROUND

Oral lichen planus (OLP) is a common, chronic immunological and inflammatory condition. Many of the OLP patients complain of xerostomia. The M3 muscarinic cholinergic receptors (MR3) are the main receptors in the salivary glands responsible for water secretion into the saliva. This study aimed to assess the level of M3 muscarinic cholinergic receptors in minor salivary glands of OLP patients.

METHODS

This case-control cross-sectional study evaluated 40 OLP patients and 22 controls. All participants completed two questionnaires (xerostomia and xerostomia inventory). Stimulated and unstimulated saliva samples were collected. The saliva flow rate was calculated by dividing the saliva volume (in milliliters) by time (in minutes). Six minor salivary glands were also surgically removed from the lower lip of patients and controls, and weighed using a digital scale with 10^-4  g accuracy. They were then frozen at -80°C, and the level of M3 receptors of the glands was determined using the ELISA kit.

RESULTS

The unstimulated and stimulated saliva flow rate was significantly lower in OLP patients. The xerostomia inventory score was significantly higher in the OLP group. The level of M3 muscarinic receptors in minor salivary glands of OLP patients was significantly higher than that in controls.

CONCLUSIONS

It may be concluded that the reduction in saliva flow significantly increases the number of M3 receptors in an attempt to compensate for this shortage and prevent xerostomia (compensatory upregulation).

Malignant transformation evidences of Oral Lichen Planus: When the time is of the essence

Oral Lichen Planus (OLP) is an inflammatory chronic disease, its potential of malignant transformation is widely known, especially for lesions affecting mucosa. This letter aims to highlight, thanks to results obtained from a long-term observation of one hundred patient suffering from OLP, the importance to set proper and sufficiently long follow-ups. An important evidence observed is the malignant developing after 4 years of observation in 4 cases of 8. This leads to conclude that follow-up for OLP lesions is required to be as long as possible in order to timeously intercept malignant transformations of these lesions and to perform a realistic early diagnosis. Final suggestion is to design more prospective studies based of long observation period.

Association of MAPK and its regulatory miRNAs (603, 4301, 8485, and 4731) with the malignant transformation of oral lichen planus

Oral lichen planus (OLP) is a potentially malignant oral lesion that may transform into oral squamous cell carcinoma (OSCC). The purpose of this study was to assess the level of expression of MAPK/ERK1/2 gene, and microRNA (miR)-603, 4301, 8485, and 4731 in the MAPK signaling pathway in OLP and OSCC lesions. This case-control study evaluated 26 OSCC, 20 OLP and 20 healthy control tissue specimens. After RNA extraction, the respective miRNA and MAPK/ERK1/2 mRNA levels were assessed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Significant upregulation of MAPK/ERK1/2 gene was noted in the OLP and OSCC specimens compared with healthy controls (p < 0.001). The expression level of miR-4731 was significantly lower in the OLP and OSCC specimens than in the healthy specimens (p < 0.001). The expression of MiR-603 was the lowest in OLP, followed by OSCC and then the control group (p < 0.001). No significant difference was found in miR-4801 levels between OSCC and OLP specimens compared with healthy controls (p = 0.43 and p = 0.86, respectively). In addition, a non-significant decrease in miR-8485 levels was noted in the OSCC and OLP specimens compared with healthy controls (p = 0.98 and p = 0.61, respectively). A significant decrease in level of miR-603 was noted in OLP compared with OSCC group (p < 0.001). The miR-4801 and miR-8485 expression levels were directly correlated with MAPK/ERK1/2 mRNA expression (p = 0.01). Higher expression level of MAPK/ERK1/2, miR-603, miR-4801, and miR-4731, and lower expression level of miR-8485 were correlated with significantly lower overall survival rate in OSCC patients. The increased expression of MAPK/ERK1/2 and decreased expression of miR-603 and miR-4731 are associated with greater risk of OLP malignant transformation and poor histopathological characteristics of OSCC.

The Relationship between the Concentration of Salivary Tyrosine and Antioxidants in Patients with Oral Lichen Planus

The diagnosis of oral lichen planus (OLP) is based on clinical examination and histopathological criteria. Noninvasive diagnostics of saliva may be considered as a confirmation of OLP diagnosis and a potential alternative to an invasive method. The objective of the present study was to evaluate the relationship between the level of tyrosine (Tyr) as well as antioxidants like uric acid (UA) and glutathione peroxidase (GPx) activity in the saliva of patients with OLP in comparison with the control group (healthy subjects without any oral changes). A total of 40 patients with OLP and 40 healthy volunteers were selected for the study based on the modified WHO diagnostic (clinical and histopathological) criteria. High-performance liquid chromatography (HPLC) was performed for Tyr concentration, while GPx activity and uric acid levels were determined by a colorimetric method. The concentrations of Tyr, UA, and GPx activity were statistically lowered in OLP patients compared to the control group. All examined parameters correlated strongly and positively with each other. Mean values of salivary UA concentrations differed between the groups of OLP patients (reticular and erosive forms) and controls (206.66 vs. 196.54 vs. 218.49 μmol/L, respectively, p = 0.001). A similar trend was demonstrated in salivary Tyr concentration which differed statistically between the study and control groups (0.08 vs. 0.07 vs. 0.13 μmol/L, respectively, p = 0.001). Determining of a relationship between the concentrations of Tyr, UA, and GPx activity may be useful in the prognosis of OLP. The HPLC method may be employed, as an additional noninvasive diagnostic procedure to screen OLP patients, during the routine diagnostics of salivary biochemical parameters such as aromatic amino acids.

Oral lichen planus and associated comorbidities: An approach to holistic health

Lichen planus (LP) is a chronic inflammatory disorder with involvement of skin, oral and genital mucosa, scalp, and nail appendages. Oral lichen planus (OLP) lesions demonstrate a number of morphologic presentations, persist for a long time with rare self-resolution, and undergo malignant changes. OLP has been associated with numerous systemic connotations such as metabolic syndrome, diabetes mellitus, hypertension, thyroid diseases, psychosomatic ailments, chronic liver disease, gastrointestinal diseases, and genetic susceptibility to cancer. The oral health physician should be aware of these systemic associations and should work in close connect with the primary healthcare physicians to rule out the predisposing factors for the associated comorbidities. This article aims to highlight the various systemic associations of OLP and warrants the screening of these ailments in OLP for prevention and effective management.

The Gingival Oral Lichen Planus: A Periodontal-Oral Medicine Approach

We present a case of a 77-year-old female who suffered from oral lichen planus (OLP) involving her gingiva and bilateral buccal mucosa for over 6 months. We showed that oral hygiene measures and conventional periodontal treatment and strict maintenance were sufficient to control the gingival involvement of OLP. The mechanism of OLP is complex and not yet fully understood. The focus of discussion in our case was that knowledge and understanding of gingival pathology are fundamental for a determined management approach. Our case was managed according to the suggested protocols in previous case studies. A multidisciplinary approach allowed for accurate diagnosis and treatment tailored to the presented case.

Topical pimecrolimus versus betamethasone for oral lichen planus: a randomized clinical trial

OBJECTIVES

Oral lichen plans (OLP) is a potentially malignant inflammatory mucocutaneous disease. CD133 is an investigated surface marker for cancer stem-like cells (CSCs) that may be involved in tumor initiation in head and neck carcinomas. We compared short-term clinical effectiveness of topical pimecrolimus as selective inflammatory cytokine release inhibitor with betamethasone cream for erosive/atrophic OLP and investigated the influence of this therapy on CD133 expression.

MATERIAL AND METHODS

Thirty patients were randomly assigned into two equal groups to receive topical pimecrolimus (group I) or betamethasone (group II) four times daily for 4 weeks. A marker lesion in each patient were assessed at baseline using clinical score (CS) and visual analog scale (VAS) then at 1, 2, and 4 weeks and after 4 weeks of treatment-free period. CD133 expression was detected in pre- and post-treatment immunostained sections.

RESULTS

Both drugs showed a reduction in CS, VAS, and CD133 expressions after treatment termination (p < 0.001). Pimecrolimus-treated lesions showed significant higher 1st week reduction in severity (33.1% (22.2)), pain score (57.53% (14.27)), less recurrence in follow-up period and less CD133 expression by the end of the 1st 4 weeks compared with betamethasone.

CONCLUSION

Pimecrolimus showed earlier clinical response and less recurrence rate compared with standard topical corticosteroid in symptomatic OLP lesions, and both treatment reduced CD133-positive CSC population.

CLINICAL RELEVANCE

The study proved the benefits of topical pimecrolimus in early management of painful lesions of OLP and its ability to inhibit CSCs, suggesting a possible role in reducing risk of malignant transformation.

Expression and significance of phosphodiesterase 4B gene in peripheral blood of patients with oral lichen planus

BACKGROUND

The pathogenesis of oral lichen planus (OLP) may be related to mental factors. In this study, we investigated the molecular mechanism of mental factors in the development of OLP.

METHODS

The normal control group and OLP patients were tested and evaluated by Zung self-rating anxiety scale and self-rating depression scale. Secondly, Agilent human LncRNA chip technology was used to detect differential genes in the total RNA of the normal control group and OLP patients, and to screen out the differentially expressed genes related to anxiety and depression. Thirdly, we verified the genes at gene level and protein level, respectively.

RESULTS

Zung self-rating anxiety scale and self-rating depression scale showed that tendency of anxiety and depression in OLP patients is significantly higher than that in normal controls, but there was no significant difference between the erosion form group and the reticular form group; the duration of OLP showed significant negative correlations between degree of anxiety and depression. Microarray analysis showed there were four differential genes (PDE4B, RGS2, SYNGR1, and SYNE1) related to anxiety and depression in OLP patients; real-time qPCR confirmed the expression of PDE4B mRNA was lower in the peripheral blood of normal control group (P < 0.001). The expression of RGS2, SYNGR1, and SYNE1 mRNA was higher in the normal control group (P < 0.05, P < 0.05, P < 0.05). Wes automatic western blot confirmed that the expression of PDE4B protein was lower in the peripheral blood of the normal control group (P < 0.01).

CONCLUSION

PDE4B gene may play a role in the pathogenesis of OLP.

Expression and clinical significance of periostin in oral lichen planus

Oral lichen planus (OLP) is a chronic inflammatory lesion involving the oral mucosa, which has a high likelihood of progressing to cancer. The present study investigated the periostin expression in the mucosa and serum of patients with OLP and its correlation with serum cytokines. A total of 117 patients with OLP and 110 healthy controls were included in the study. The protein expression of periostin were measured in the OLP and normal oral mucosa by immunohistochemistry. ELISA was performed to measure the serum levels of periostin, tumour necrosis factor-α (TNF-α), interleukin (IL)-6, interferon-γ (IFN-γ), IL-4 and thymic stromal lymphopoietin (TSLP). Compared with the control group the OLP group had a significantly increased number of cases with high periostin expression in the oral mucosa and a significantly increased serum periostin level (P<0.05). Among all 117 OLP subjects, high periostin expression was associated with higher serum IL-6, TNF-α, TSLP and tissue mast cell density. High periostin expression was also significantly associated with a lower IFN-γ/IL-4 ratio (P<0.05). The present study concluded that periostin expression was increased in the oral mucosa and serum of patients with OLP and was associated with inflammatory response, T helper 2 cytokine-predominant immune imbalance, increased mast cell count and TSLP. The modulation of periostin may represent an attractive novel therapeutic target.