Distribution of interleukin-2,-4,-10, tumour necrosis factor-alpha and transforming growth factor-beta mRNAs in oral lichen planus

In the present study. MRNA for the cytokines interleukin-2 (IL-2), IL-4, IL-10 tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor beta-1 (TGF-beta-1) were investigated in oral lichen planus (OLP) lesions using in situ hybridization with S-35-labelled oligonucleotide probes on frozen tissue sections. In addition, the expression of interferon-gamma (IFN-gamma), IL-10 and IL-4 mRNAs was analysed in cultured lesional T lymphocytes from oral lichen planus by polymerase chain reaction. Cells expressing mRNA for IL-2, IL-4, IL-10, TNF-alpha and TGF-beta(1) were found in all the biopsies studied. Approximately 1-2% of the total number of infiltrating cells in the lesions were positive for each of the different cytokine mRNAs. Most biopsies contained basement membrane-oriented, mRNA-positive cells. In the cultured T-cell lines, message for IFN-gamma was detected in all the patients, IL-10 in all but one, and IL-4 in just one of the seven patients investigated. The results suggest that mRNA for both pro- and anti-inflammatory cytokines, i.e., mixed T-helper 1 (T(H)1) and T(H)2 cytokine profiles, are generated simultaneously by a limited number of cells in chronic lesions of OLP. (C) 1999 Elsevier Science Ltd. All rights reserved.

Expression of RANTES and CCR1 in oral lichen planus and association with mast cell migration

Background: T lymphocytes and mast cells infiltrate the lamina propria in oral lichen planus (OLP). Chemokines and their receptors are involved in T cell and mast cell migration and accumulation during the inflammatory process. Methods: In the present study, we investigated the role of RANTES and its receptors in OLP using immunohistochemistry, RT-PCR and an in vitro chemotaxis assay. Results: RANTES and CCR1 were expressed on T cells and mast cells in OLP, while OLP lesional T cell supernatants stimulated CCR1 mRNA expression in a human leukemia mast cell line (HMC-1). TNF-alpha stimulated CCR1, CCR4 and CCR5 mRNA expression in the same cell line. OLP lesional T cell supernatants stimulated HMC-1 migration, which was partly inhibited by anti-RANTES antibody. Conclusions: The present study shows, for the first time, the distribution of RANTES and CCR1 in OLR It is hypothesized that RANTES and CCR1 may play important roles in mast cell trafficking and related events in OLP.

Matrix metalloproteinases and their inhibitors in oral lichen planus

Background: Oral lichen planus (OLP) is characterized by a subepithelial lymphocytic infiltrate, basement membrane (BM) disruption, intra-epithelial T-cell migration and apoptosis of basal keratinocytes. BM damage and T-cell migration in OLP may be mediated by matrix metalloproteinases (MMPs). Methods: We examined the distribution, activation and cellular sources of MMPs and their inhibitors (TIMPs) in OLP using immunohistochemistry, ELISA, RT-PCR and zymography. Results: MMP-2 and -3 were present in the epithelium while MMP-9 was associated with the inflammatory infiltrate. MMP-9 and TIMP-1 secretion by OLP lesional T cells was greater than OLP patient (p

The pathogenesis of oral lichen planus

Both antigen-specific and non-specific mechanisms may be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8(+) cytotoxic T-cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. These mechanisms may combine to cause T-cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T-cell migration, and keratinocyte apoptosis in OLP. OLP chronicity may be due, in part, to deficient antigen-specific TGF-beta1-mediated immunosuppression. The normal oral mucosa may be an immune privileged site (similar to the eye, testis, and placenta), and breakdown of immune privilege could result in OLP and possibly other autoimmune oral mucosal diseases. Recent findings in mucocutaneous graft-versus-host disease, a clinical and histological correlate of lichen planus, suggest the involvement of TNF-alpha, CD40, Fas, MMPs, and mast cell degranulation in disease pathogenesis. Potential roles for oral Langerhans cells and the regional lymphatics in OLP lesion formation and chronicity are discussed. Carcinogenesis in OLP may be regulated by the integrated signal from various tumor inhibitors (TGF-beta1, TNF-alpha, IFN-gamma, IL-12) and promoters (MIF, MMP-9). We present our recent data implicating antigen-specific and non-specific mechanisms in the pathogenesis of OLP and propose a unifying hypothesis suggesting that both may be involved in lesion development. The initial event in OLP lesion formation and the factors that determine OLP susceptibility are unknown.

Mast cell/T cell interactions in oral lichen planus

Lichen planus is a disorder characterized by lesions of the skin and oral mucous membranes. Although many patients have involvement of both skin and oral mucosa at some stage during the progress of the disease, a larger group has oral involvement alone. It has been reported that oral lichen planus (OLP) affects one to two percent of the general population and has the potential for malignant transformation in some cases (1, 2). Like many chronic inflammatory skin diseases, it often persists for many years. Numerous disorders may be associated with OLP such as graft-vs.-host disease and Hepatitis C virus infection (3), however, it is unclear how such diverse influences elicit the disease and indeed whether they are identical to idiopathic OLP Available evidence supports the view that OLP is a cell-mediated immunological response to an induced antigenic change in the mucosa (4-6). Studies of the immunopathogenesis of OLP aim to provide specific novel treatments as well as contributing to our understanding of other cell-mediated inflammatory diseases. In this paper, the interactions between mast cells and T cells are explored from the standpoint of immune regulation. From these data, a unifying hypothesis for the immunopathogenesis of OLP is then developed and presented.

Intra-epithelial CD8+ T cells and basement membrane disruption in oral lichen planus

Background: We investigated basement membrane (BM) disruption and the distribution of mast cells (MCs) and T cell subsets, in oral lichen planus (OLP) and normal buccal mucosa (NBM) using immunohistochemistry. In OLP, there were increased numbers of tryptase(+) MCs in areas of BM disruption (P

Oral lichen planus: Causes, diagnosis and management

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology. In this paper we review the clinical and histological features of OLP, process of OLP diagnosis, causes of OLP, management of OLP patients and medical treatment of OLP lesions. Approximately 0.2 per cent OLP patients develop intra-oral carcinoma each year compared with approximately 0.005 per cent Australian adults. Possible mechanisms of increased oral cancer risk in OLP patients are presented. The aims of current OLP therapy are to eliminate mucosal erythema and ulceration, alleviate symptoms and reduce the risk of oral cancer. Patient education may improve the outcomes of OLP therapy and further reduce the risk of oral cancer in OLP patients. Although OLP may be diagnosed clinically, appropriate specialist referral is required for: (i) histological diagnosis; (ii) assessment of causative/exacerbating factors, associated diseases and oral cancer risk; (iii) patient education and management; (iv) medical treatment; and (v) long-term review and re-biopsy as required.

Th1 cytokines in oral lichen planus

Background: Cell-mediated immune responses in oral lichen planus (OLP) may be regulated by cytokines and their receptors. Methods: In situ cytokine expression and in vitro cytokine secretion in OLP were determined by immunohistochemistry and ELISA. Resulults: The majority of subepithelial and intraepithelial mononuclear cells in OLP were CD8(+) . In some cases, intraepithelial CD8(+) cells were adjacent to degenerating keratinocytes. CD4(+) cells were observed mainly in the deep lamina propria with occasional CD4(+) cells close to basal keratinocytes. Mononuclear cells expressed IFN-gamma in the superficial lamina propria and TNF-alpha adjacent to basal keratinocytes. Basal keratinocytes expressed TNF-alpha as a continuous band. TNF R1 was expressed by mononuclear cells and basal and suprabasal keratinocytes. There was variable expression of TGF-beta1 in the subepithelial infiltrate while all intraepithelial mononuclear cells were TGF-beta1(-) . Keratinocytes in OLP stained weakly for TGF-beta1. Unstimulated OLP lesional T cells secreted IFN-gammain vitro . TNF-alpha stimulation down-regulated IFN-gamma secretion and up-regulated TNF-alpha secretion. IL-4, IL-10 and TGF-beta1 secretion were not detected. Conclusions: These data suggest the development of a T helper 1 immune response that may promote CD8(+) cytotoxic T-cell activity in OLP.

Cyclosporine A, an alternative to the oral lichen planus erosive treatment

We present a double-blind study in two groups afflicted with oral lichen planus erythematous of long evolution and resistant to other treatments. We tested on it a treatment with Cyclosporine A (CyA) which had been successfully used before by many dermatologists. In the group A we used mouthwashes with a 5 ml Cyclosporine A solution to a 10% in olive oil of 0.4 degrees of acidity for five minutes, three times a day for eight weeks. In the control group we used acetonide of triamcinolone 01% in aqueous solution. Patients in group A improved considerably in their symptomatology in a 90% against a 60% in group B. In group A we could appreciate a disappearance of the symptomatology after two weeks of treatment in 60% of patients against 30% in group B. CyA can be an alternative to the conventional treatments in the acute period of lichen planus although it can not be considered as a first option drug because of the high cost of the treatment. For long term, results are not so good and we consider that extensive studies are necessary

Clinical features of oral lichen planus. A retrospective study of 65 cases

Objectives: To describe the clinical features of patients diagnosed with oral lichen planus (OLP) and to establish the prevalence of its malignant transformation in our setting. Study design: A retrospective study was made of 65 patients clinically and histologically diagnosed with OLP in the Service of Oral Surgery (Dental Clinic of the University of Barcelona, Spain) in the period 1990-2005. A descriptive and bivariate statistical analysis was made. Results: The mean patient age was 59 years (SD ± 14.9). Most of the patients (61%) were women, and the most frequent location of the lesions was the buccal mucosa (90.8%). White forms of OLP were noted in 66% of the cases, and 46.2% of the patients reported symptoms of some kind. The patients diagnosed with diabetes mellitus (20%) showed a larger proportion of red lesions (p=0.088). No statistically significant association was observed between chronic liver disease and the OLP lesion types or symptoms. Two cases of squamous cell carcinoma were identified in two patients previously or simultaneously diagnosed with OLP. A statistically significant correlation was observed between dysplastic changes / malignization of the lesions and smoking habit (p=0.019). An association to alcohol abuse was also noted, though in this case statistical significance was not reached (p=0.085). Conclusions: The clinical features of our study population were similar to those described in other studies. Diabetic patients with OLP were seen to be more susceptible to the development of atrophic-erosive lesions. Smokers and/or patients with alcohol abuse in turn showed a greater tendency to develop dysplastic changes / malignization in the histopathological study of the lesions

Molecular Markers of Oral Lichen Planus

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease and is detected in between 0.5% - 2.2% of the population. WHO has defined OLP as a potentially precancerous disorder, representing a generalized state associated with a significantly increased risk of cancer. However, only 0.5 – 2.9% of OLP lesions will progress to cancer. Currently, there are no prognostic markers to identify the lesions at increased risk for malignant transformation. The main aim of these studies was to identify cellular and molecular markers in order to understand the pathogenesis of atrophic OLP and its progression towards malignancy. Selected markers for cell proliferation, adhesion, apoptosis, and lymphocytic infiltration were assessed by immunohistochemistry in addition to static cytometry analyses for DNA content. DNA quantification of epithelial cells in 82 biopsy samples derived from atrophic lichen planus showed altered DNA content in 41% of the samples. DNA content was associated with proliferation activity, topoisomerase IIalpha, desmocollin-1 and infection with human papillomavirus. CD27+ and CD38+ lymphocytes were detected in inflammatory cell infiltrate, indicating an abnormal homing of B cells from blood circulation to tissue. Physiologic cell death, apoptosis, is frequently seen in OLP, but its pathways are unknown. Here it was shown that caspases 2 and 12 were up-regulated in OLP, indicating that intracellular apoptosis, rather than an external causal factor, is triggering apoptosis. However, this thesis could not identify any singular prognostic marker of malignancy in OLP. Thus, every OLP patient should receive regular follow-up care to identify cancer risk patients at an early stage.