Oral lichen planus in patients infected or noninfected with hepatitis C virus: the role of autoimmunity

Serum immunoglobulin and the threshold of Fc receptor-mediated immune activation

Antibodies can mediate immune recruitment or clearance of immune complexes through the interaction of their Fc domain with cellular Fc receptors. Clustering of antibodies is a key step in generating sufficient avidity for efficacious receptor recognition. However, Fc receptors may be saturated with prevailing, endogenous serum immunoglobulin and this raises the threshold by which cellular receptors can be productively engaged. Here, we review the factors controlling serum IgG levels in both healthy and disease states, and discuss how the presence of endogenous IgG is encoded into the functional activation thresholds for low- and high-affinity Fc receptors. We discuss the circumstances where antibody engineering can help overcome these physiological limitations of therapeutic antibodies. Finally, we discuss how the pharmacological control of Fc receptor saturation by endogenous IgG is emerging as a feasible mechanism for the enhancement of antibody therapeutics.

A personal journey through Oral medicine: The tale of hepatitis C virus and oral lichen planus

Around 30 years ago, the hepatitis C virus (HCV) was identified and soon it was shown that this virus, further to the liver, could affect a variety of organ systems. This article summarizes how an association between HCV and a relatively common oral disorder, oral lichen planus (OLP), was revealed. Through key publications, many of them published in Journal of Oral Pathology and Medicine, it is shown the building of strong epidemiologic evidence supporting the association and how a plausible pathogenic link between HCV and OLP was discovered. As HCV infection is now potentially curable, modern direct antiviral agents can be used to effectively cure also OLP in HCV-infected patients.

Photobiomodulation is effective in oral lichen planus: A randomized, controlled, double-blind study

OBJECTIVES

To compare the efficacy of photobiomodulation to that of topical clobetasol 0.05% in patients with symptomatic oral lichen planus (OLP).

SUBJECTS

Thirty-four patients with symptomatic OLP were randomly allocated into two groups: (a) the Control group (n = 17), application of topical clobetasol propionate 0.05% three times a day for 30 consecutive days with laser placebo applied twice a week to mask the treatment, and (b) the photobiomodulation group (n = 17), laser application twice a week, totalling 8 sessions, and gel placebo for 30 consecutive days to mask the treatment. Evaluations were performed once a week during treatment and 30, 60 and 90 days after treatment. The following parameters were evaluated: pain, clinical scores, clinical resolution and recurrence rate.

RESULTS

Photobiomodulation and propionate clobetasol 0.05% were able to significantly decrease pain in oral lichen planus patients and improve clinical scores during treatment and follow-up. Both the Control and photobiomodulation groups presented similar clinical resolution and recurrence rates. Most importantly, no difference was observed between treatments during treatment and follow-up.

CONCLUSIONS

These findings indicate that photobiomodulation twice a week is as effective as corticoid therapy in treating oral lichen planus. Moreover, photobiomodulation is a safe and non-invasive therapy with the remarkable advantage of no adverse effects.

Potential pathogenic mechanisms involved in the association between lichen planus and hepatitis C virus infection

Lichen planus (LP) is an immune-mediated inflammatory disease that particularly affects the skin and mucous membranes. Its etiology remains elusive, however some trigger factors, including viral or bacterial antigens, drugs and metals, have been postulated. There is a higher prevalence of hepatitis C virus (HCV) infection among patients with LP, with some geographical variations. HCV is an enveloped RNA virus that belongs to the Flaviviridae family and in most instances causes chronic liver infections. It has been hypothesized that HCV may contribute to LP development, but the link between the two disorders is not fully understood. It is still debatable whether HCV leads to the occurrence of LP lesions directly by replication inside the infected cells or indirectly by activating immunological pathways. Molecular studies have revealed HCV RNA in specimens collected from patients with LP. The autoimmune theory was also suggested given that several studies have revealed viral replication and immune response activation associated with autoantibody synthesis. The aim of this review is to summarize the main potential mechanisms involved in the association between LP and HCV infection. Understanding the link between the two disorders may shed some light on the pathogenesis of LP, which is a challenging issue.

Efficacy of photobiomodulation on oral lichen planus: a protocol study for a double-blind, randomised controlled clinical trial

INTRODUCTION

Oral lichen planus (OLP) is an idiopathic chronic mucocutaneous disease with a wide range of clinical manifestations, including white reticular patches, erosive/ulcerative and atrophic lesions, both associated with intense symptomatology. Topical corticosteroids are commonly used as standard therapy. However, patients frequently present relapses after the discontinuation of treatment as well as developing resistance to corticosteroid therapy. Photobiomodulation (PBM) has been shown to be a potential therapeutic tool to treat inflammatory disorders, including OLP. The aim of this study was to compare the efficacy of PBM (660 nm) with corticosteroid therapy with clobetasol propionate 0.05% for the treatment of OLP.

METHODS AND ANALYSIS

Forty-four patients with symptomatic and histopathological diagnosis of OLP will be randomised into two experimental groups in a double-blind manner: control group (n=22): clobetasol propionate 0.05%+placebo PBM, and experimental group (n=22): PBM (λ=660 nm, power 100 mW, radiant exposure: 177 J/cm² and 0.5J per point)+placebo gel. Laser will be applied 2×/week for 1 month and clobetasol propionate three times a day for 30 days and the same for placebo treatments. The primary variable (pain) and the secondary variables (clinical score, evaluation of functional scores, clinical resolution, OLP recurrence, quality of life and anxiety and depression) will be evaluated at the baseline, once a week during treatment (depending on the variables) and after 30 days and 60 days of follow-up. Pain will be evaluated using visual analogue scale and clinical characteristics will be scored using the Thongprasom Index. The quality of life and anxiety and depression will be evaluated by Oral Health Impact Profile-14 questionnaire and by Hospital Anxiety and Depression Scale for anxiety scale, respectively. The serum and salivary levels of interleukin (IL)-6, IL-10, IL-1β, INF-γ and tumour necrosis factor-α will be evaluated by ELISA at baseline and at the end of treatment.

ETHICS AND DISSEMINATION

This protocol was approved (#2.375.410) by the Nove de Julho University (UNINOVE) Research Ethics Committee. The data gathered using this protocol will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03320460.

Oral lichen planus - Differential diagnoses, serum autoantibodies, hematinic deficiencies, and management

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease that occurs more frequently in middle-aged and elderly female patients. Previous studies indicate that OLP is a T-cell dysfunction-induced localized autoimmune disease. Clinically, six types of OLP, namely reticular, papular, plaque-like, atrophic/erosive, ulcerative, and bullous types, can be identified. OLP more commonly affects buccal mucosa, tongue, and gingiva. It always has a bilateral and symmetric distribution of the oral lesions. Plaque-like and atrophic/erosive OLP may be misdiagnosed as oral leukoplakia and oral erythroleukoplakia, respectively. Our previous study found serum autoantibodies in 195 (60.9%) of the 320 OLP patients. Specific serum anti-nuclear, anti-smooth muscle, anti-mitochondrial, gastric parietal cell, thyroglobulin, and thyroid microsomal autoantibodies are present in 28.1%, 8.4%, 1.6%, 26.3%, 21.3%, and 24.4% of 320 OLP patients, respectively. Furthermore, we also discovered that 21.9%, 13.6%, 7.1%, 0.3%, and 14.8% of 352 OLP patients have hemoglobin, iron, vitamin B12, and folic acid deficiencies, and abnormally high serum homocysteine level, respectively. Therefore, it is very important to examine the serum autoantibody, hematinic and homocysteine levels in OLP patients before starting the treatments for OLP patients. Because OLP is an immunologically-mediated disease, corticosteroids are the drugs of choice for treatment of OLP.

Thyroid Autoimmunity and Lichen

Lichen planus (LP) and lichen sclerosus (LS) are cutaneous-mucous diseases with uncertain epidemiology. Current data, which are likely to be underestimated, suggest a prevalence in the general population of 0.1-4% for cutaneous LP, 1.27-2.0% for oral LP, and 0.1-3.3% for LS. While etiology of lichen is still unknown, clinical and histological evidence show an (auto)immune pathogenesis. Association of lichen with autoimmune thyroid disease (AITD) has been investigated in few studies. This association appears better defined in the case of LS, while is more controversial for LP. In both situations, the frequency of the association is higher in females. We review the available literature on the correlation between the different types of lichen and AITD, and the literature on the genetic risk factors which are shared by both conditions. Such data suggest that a common pathogenic mechanism could be the cause for co-occurrence of lichen and AITD, at least in some patients. Additionally, analyzing literature data and in continuity with our previous work on other autoimmune diseases, we suggest that molecular mimicry could trigger both diseases, and thus explain their co-occurrence.

A potential peptide pathway from viruses to oral lichen planus

Oral lichen planus is an idiopathic inflammatory disease of oral mucous membranes, characterized by an autoimmune epidermis attack by T cells. It remains unknown, however, how such aggressive T cells are activated in vivo to cause epidermal damage. This study analyzes the relationship at the peptide level between viruses and oral lichen planus disease. Four potentially immunogenic peptides (SSSSSSS, QEQLEKA, LLLLLLA, and MLSGNAG) are found to be shared between HCV, EBV, HHV-7, HSV-1, and CMV and three human proteins (namely pinin, desmoglein-3, and plectin). The described peptide sharing might be of help in deciphering the still unexplained immunopathogenic pathway that leads to oral lichen planus.

Efficacy of laser phototherapy in comparison to topical clobetasol for the treatment of oral lichen planus: a randomized controlled trial

Oral lichen planus (OLP) is a relatively common chronic mucocutaneous inflammatory disease and a search for novel therapeutic options has been performed. We sought to compare the efficacy of laser phototherapy (LPT) to topical clobetasol propionate 0.05% for the treatment of atrophic and erosive OLP. Forty-two patients with atrophic/erosive OLP were randomly allocated to two groups: clobetasol group (n=21): application of topical clobetasol propionate gel (0.05%) three times a day; LPT group (n=21): application of laser irradiation using InGaAlP diode laser three times a week. Evaluations were performed once a week during treatment (Days 7, 14, 21, and 30) and in four weeks (Day 60) and eight weeks (Day 90) after treatment. At the end of treatment (Day 30), significant reductions in all variables were found in both groups. The LPT group had a higher percentage of complete lesion resolution. At follow-up periods (Days 60 and 90), the LPT group maintained the clinical pattern seen at Day 30, with no recurrence of the lesions, whereas the clobetasol group exhibited worsening for all variables analyzed. These findings suggest that the LPT proved more effective than topical clobetasol 0.05% for the treatment of OLP.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Prevalence of hepatitis C and hepatitis B virus infection(s) in patients with oral lichen planus

AIM

The aim of this study was to determine the prevalence of hepatitis B virus and hepatitis C virus (HCV) infections in patients with oral lichen planus (OLP) and to compare it with that of general population.

MATERIALS AND METHODS

A total of 60 patients were included in the study. Patients were selected from the outpatient department of Rama Dental College Research Centre, Kanpur, Uttar Pradesh. Thirty patients with OLP were included in Group 1. Thirty age- and sex-matched healthy patients with no history of oral or skin lesions were included in Group 2. Detailed case history, biopsy (the most representative site of the lesion is chosen for specimen), detection of hepatitis B surface antigen (HBsAg), and detection of anti-HCV antibody were carried out.

RESULTS

The serum of the entire study sample (Group 1 and Group 2) was tested for both hepatitis C antibodies and HBsAgs with the enzyme-linked immunosorbent assay (ELISA) test (using the third generation kit). It was found negative for both HBsAgs and hepatitis C antibodies.

CONCLUSION

In the present study, all the samples including OLP patients and healthy patients were seronegative for both hepatitis B (HBsAg) and hepatitis C (HCV antibody).

Pathophysiology, etiologic factors, and clinical management of oral lichen planus, part I: facts and controversies

Lichen planus (LP) is an inflammatory disease of the stratified squamous epithelia of unknown etiology. LP affects most frequently the oral mucosa, but it may also involve other mucosa and the skin. Oral LP (OLP) most frequently affects woman aged between 30 and 60 years. Histopathologic examination typically shows orthokeratotic hyperkeratosis, basal cell degeneration, and a dense well-defined infiltrate of lymphocytes in the superficial dermis. OLP lesions may result from the induction of keratinocytes apoptosis by cytotoxic CD8+ T cells stimulated by a yet unidentified self-antigen on a genetically predisposed patient. The association of OLP with hepatitis C virus (HCV) has been more consistently demonstrated in the Mediterranean area. Although HCV RNA and HCV-specific CD4+ and CD8+ T cells have been retrieved in the mucosal lesions of patients with chronic HCV infection and OLP, the eventual pathophysiology of HCV in OLP lesions remains unclear. Available treatments of OLP are not curative, and many have potentially prominent side effects. The objectives of OLP management should be to prevent and screen for malignant transformation and alleviate symptoms on the long-term. Avoidance of potential precipitating drugs, tobacco, alcohol, and local trauma, as well as strict oral hygiene, is essential. The first-line pharmacologic treatment relies on topical steroids. Systemic steroids should be limited to the short-term cure of severe refractory OLP. Life-long clinical follow-up, at least annually, is fundamental.

Oral diseases associated with hepatitis C virus infection. Part 2: lichen planus and other diseases

Some of the most frequent extrahepatic manifestations of hepatitis C virus (HCV) infection involve the oral region predominantly or exclusively. Part 2 of this review discusses the current evidences regarding the association of lichen planus (LP) and other diseases frequently involving the oral cavity with HCV. Epidemiological data suggest that LP may be significantly associated with HCV infections especially in southern Europe and Japan but not in northern Europe. These geographical differences are possibly influenced by immunogenetic factors, the duration of the HCV infection and the design of the published studies. Because of the fact that most of the studies published are retrospective, it is impossible to establish whether the HCV exposure occurred earlier to or after the onset of disease and more prospective studies are clearly warranted. As the virus may replicate in the skin and oral mucosa and HCV-specific T lymphocytes can be found in the oral mucosa of patients with chronic hepatitis C and LP, HCV may be implicated in the pathogenesis of LP. However, little attention has been paid to the variable effect of therapy with interferon-alpha (IFN-alpha), with or without ribavirin for LP. Conversely, it is unlikely that other oral diseases such as oral carcinoma, pemphigus and Behcet disease are triggered by HCV.

Prevalence of stratified epithelium-specific antinuclear antibodies in 138 patients with lichen planus

BACKGROUND

Antibodies to stratified epithelia characterize chronic ulcerative stomatitis, an entity that very closely resembles erosive lichen planus both clinically and histologically. These antibodies are directed against a 70-kd antigen.

OBJECTIVE

Our aim was to verify whether antibodies to stratified epithelia are present in patients with common lichen planus.

PATIENTS AND METHODS

One hundred thirty-eight patients with various forms of lichen planus were studied. Indirect immunofluorescence was performed on both monkey esophagus and HEp2-2000 cells. Immunoblotting was done with cultured keratinocytes used as the source antigen.

RESULTS

Nineteen patients had antibodies to stratified epithelia (in 9 directed against an antigen of 70 kd). Forty-eight patients had circulating antibodies detected by indirect immunofluorescence on both monkey esophagus and HEp2-2000 cells (in 7 directed against an antigen of 70 kd). Indirect immunofluorescence was positive only on HEp2-2000 cells in 21 patients. Indirect immunofluorescence was negative in 50 patients on both HEp2-2000 cells and monkey esophagus. None of the last 71 patients had antibodies directed to an antigen of 70 kd.

LIMITATIONS

This is a serological study; results from direct immunofluorescence studies would be interesting.

CONCLUSION

Antibodies to stratified epithelia directed to an antigen of 70 kd are not exclusive to chronic ulcerative stomatitis, but are also present in some patients with lichen planus.

Detection of antibodies against p63 and p73 isoforms in sera from patients diagnosed with oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory disease of oral mucosa. Despite numerous publications and intense research, the etiology of OLP is still unknown, however, autoimmunity as a possible causative factor has been discussed.

METHODS

In the present study sera from 20 patients clinically and histologically diagnosed with OLP were analyzed for antibodies directed toward p53, p63, and p73 using Western blot.

RESULTS

Sera from two patients reacted with all six p63 isoforms, and one also with p73. The strongest reaction was noted against the TAp63beta protein, which is the most potent transactivator of all p63 proteins and is implicated in the differentiation of stratified epithelia.

CONCLUSIONS

This is the first demonstration of antibodies directed against all p63 and some p73 isoforms in sera from patients diagnosed with OLP.

Scoring system for monitoring oral lichenoid lesions: a preliminary study

BACKGROUND

Currently, there is no universal system for scoring the severity of lichenoid lesions of the oral cavity that is easy to use, reproducible and that is representative of the different clinical forms of the disease.

OBJECTIVES

In this study, a scoring system was developed to monitor the severity of oral lichen planus (OLP) and chronic oral graft-versus-host disease (cGVHD).

METHODS

Six patients with OLP and three with cGVHD were studied. This scoring system was utilized to compare the severity of disease within and between patients. Three investigators independently reviewed photographs taken from each patient and scored the severity of disease. Inter and intra-observer consistency was evaluated using the Spearman rank correlation analyses.

RESULTS

Intra-observer reliability was 0.98 (Spearman correlation coefficient) and inter-observer reliability was 1.00.

CONCLUSION

This scoring system is easy-to-use, reproducible, representative of the severity of the disease and useful for monitoring OLP and cGVHD.

Current controversies in oral lichen planus: Report of an international consensus meeting. Part 1. Viral infections and etiopathogenesis

Despite recent advances in understanding the immunopathogenesis of oral lichen planus (LP), the initial triggers of lesion formation and the essential pathogenic pathways are unknown. It is therefore not surprising that the clinical management of oral LP poses considerable difficulties to the dermatologist and the oral physician. A consensus meeting was held in France in March 2003 to discuss the most controversial aspects of oral LP. Part 1 of the meeting report focuses on (1) the relationship between oral LP and viral infection with special emphasis on hepatitis C virus (HCV), and (2) oral LP pathogenesis, in particular the immune mechanisms resulting in lymphocyte infiltration and keratinocyte apoptosis. Part 2 focuses on patient management and therapeutic approaches and includes discussion on malignant transformation of oral LP.

Hepatitis C virus-associated oral lichen planus: is the geographical heterogeneity related to HLA-DR6?

BACKGROUND

The association between hepatitis C virus (HCV) and oral lichen planus (OLP) is more common in the Mediterranean area and Japan, possibly because of immunogenetic factors.

METHODS

Intermediate-resolution HLA-DRB typing by hybridization with oligonucleotide probes was performed in 31 Italian OLP patients with HCV infection, in 45 Italian OLP and in 48 British OLP patients without HCV infection. As healthy controls we included data from 145 unrelated Italian and 101 unrelated British bone marrow donors.

RESULTS

Italian HCV+ve OLP patients possessed the HLA-DR6 allele more frequently than Italian and British OLP patients without HCV infection (51.6% vs. 17.7% vs. 16.7%; P corrected = 0.028 and 0.017, respectively). There was no difference in the frequency of the HLA-DR6 allele between Italian and British control subjects.

CONCLUSIONS

The present data suggest that HLA-DR6 may be responsible for the peculiar geographic heterogeneity of the association between HCV and OLP.

Immune response in patients with oral lichen planus and HCV infection

In recent years an association between oral lichen planus (OLP) and HCV infection has been reported, but the frequency of this association seems to differ in the various geographic areas. It is clear, instead, that some abnormalities occur in the immune-regulation mechanisms of patients with OLP and it is thought to be due to the chronic antigenic stimulus of HCV that causes functional disorders of the immune system in infected patients. Possible immunologic difference between 17 patients with OLP and HCV+ and 17 patients with OLP and HCV- were investigated using standard immunofluorescence and flow cytometry techniques. The distribution of T and B cells was normal in all patients examined, while NK CD56+ cells were increased, above all in HCV- patients. About 65% of T CD4+ lymphocytes coexpressed the CD45RO isoform (p=0.002), while approximately 32% expressed CD45RA, without significant differences in comparison to HCV+ subjects (p>0.05). Moreover, almost all the CD4+CD45RO+ subpopulation coexpressed CD29 in all patients examined. No significant differences between the two groups of patients were detected as to the increase of cytotoxic T CD8+CD57+ lymphocytes. The B cells CD19+CD5+ responsible for the production of "natural" antibodies were detectable in both the examined groups, even if not in all HCV+ subjects (30% +/- 10.1 in HCV- and 27% +/- 19.4 in HCV+ patients; p=0.47). These findings suggest the existence of differences in lymphocyte subpopulations between OLP-HCV+ subjects and OLP-HCV- patients.

The clinical manifestations and treatment of oral lichen planus

The progress in research on OLP and other autoimmune diseases has been significant. Coupled with a growing recognition of the clinical features and treatment options by dentists and physicians and fueled by the advances in immunosuppressive therapies, research will undoubtedly provide new insights into this complex disorder. It is likely that what is learned will enhance the understanding not only of OLP but also of many other mucocutaneous diseases.

Drug reaction to ursodeoxycholic acid: lichenoid drug eruption in an infant using ursodeoxycholic acid for neonatal hepatitis

Lichenoid drug eruptions are skin reactions associated with a number of drugs and chemicals. They are rare in infants. We report here an infant who presented with neonatal hepatitis and who was being treated with ursodeoxycholic acid. The infant developed lichenoid skin eruptions in the third week of the therapy. The lesions have resolved two months after the discontinuation of the drug. To our knowledge, this is the first infant case of lichenoid drug eruption associated with ursodeoxycholic acid.

Molecular evidence that the hepatitis C virus replicates in the oral mucosa

BACKGROUND/AIMS

Patients infected with the hepatitis C virus (HCV) often have extrahepatic manifestations, which significantly contribute to HCV-related morbidity, but whose pathogenesis is largely unknown. Our aim was to evaluate the HCV replication in oral mucosa of chronic hepatitis C patients.

METHODS

We collected oral mucosa specimens from 17 anti-HCV-positive and four anti-HCV-negative patients. Fifteen had oral lichen (12 anti-HCV-positive). Total mucosa RNA was extracted and analyzed for presence and titer of genomic and negative-strand HCV RNA. Findings were compared with clinical and pathological features.

RESULTS

Genomic and negative-strand HCV RNA were detected, respectively, in 12 of 17 (70.6%) and four of 17 (23.5%) specimens from the chronic hepatitis C patients. No negative-strand HCV RNA was detected in five anti-HCV-positive patients without lichen (including three with normal mucosa). Presence and titer of the negative-strand HCV RNA were independent of HCV genotype, serum viral load, and histological diagnosis of liver lesions. The phylogenetic analysis of the envelope 2 region cloned from a normal mucosa and the corresponding serum further suggested that only lichen tissues appear to harbor replicating HCV.

CONCLUSIONS

HCV may occasionally replicate in oral lichen tissue, possibly contributing to the pathogenesis of mucosa damage.

Oral lichen planus: immunohistology of mucosal lesions

BACKGROUND

Current evidence suggests that immunological mechanisms are involved in oral lichen planus (OLP) pathogenesis. The events implicate activated epithelia that comprise antigen-presenting Langerhans cells, immunocompetent keratinocytes and subepithelial inflammatory infiltrate. Also, the presence of a high density of leucocyte cells may occur for the expression of a variety of adhesion molecules. The aim of this study was to analyse the immunoexpression of some adhesion molecules as well as lymphocytic markers in order to determine the disease pathogenesis in a Venezuelan population.

METHODS

The 18 OLP and 10 normal oral mucosa biopsies were immunostained for CD4, CD8, CD1a, LFA-1, VCAM-1 and ICAM-1.

RESULTS

The results showed an increased number of CD4+, CD8+, CD1a+ cells in OLP. Serial sections showed CD4+ and CD8+ cells also expressed LFA-1. The expression of ICAM-1 and VCAM-1 were significantly higher in OLP.

CONCLUSIONS

The immunological reaction begins with Langerhans cells activation, which presents an antigen to CD4+ lymphocytes. Those cells through ICAM-1 and LFA-1 promote epithelial destruction. Afterwards, cytokine production, ICAM-1 and VCAM-1 expression can activate CD8+ lymphocytes leading to the chronic form of the disease.

Concurrent oral lichen planus and primary sclerosing cholangitis

Four patients with concomitant oral lichen planus (OLP) and primary sclerosing cholangitis (PSC) are presented. Associations have been made between OLP and chronic liver disease, namely hepatitis C and primary biliary cirrhosis, but the aetiology and commonality between the diseases has yet to be confirmed. An immunological link is currently favoured. PSC may be a further association with OLP, possibly involving the immune system.

Psychoneuroimmunology in oral biology and medicine: the model of oral lichen planus

Rheumatoid arthritis involves psychoneuroendocrine-immunopathological comorbidities. In the stoma, patients with rheumatoid arthritis frequently show signs of periondontal disease consequent to elevated levels of crevicular proinflammatory cytokines. It is not clear whether rheumatoid arthritis may manifest in association with immunopathological manifestations of the oral soft mucosa. Oral lichen planus (OLP), first described by E. Wilson in 1859, is a T-cell-mediated inflammatory disease whose lesions characteristically lack B cells, plasma cells, immunoglobulin. or complement. It is increasingly well characterized and recognized as a model for psychoneuroimmunology research in oral biology and medicine. To date, we have shown an association between changes in hypothalamic-pituitary-adrenal (HPA) regulation, systemic markers of cellular immunity and mood states, with clinical stages of OLP (i.e., atrophic vs. erosive vs. bullous lesions). We report significant associations (p < 0.05) between the stage of OLP, HPA deregulation, and altered distribution and functional responses of naïve CD4(+) cells. We emphasize the need to study in greater details the psychoneuroendocrine-immune inter-relationships in OLP, and we propose a novel neuroimmune hypothesis for OLP.

Increased frequency of HLA-DR6 allele in Italian patients with hepatitis C virus-associated oral lichen planus

BACKGROUND

Recent controlled studies have confirmed that hepatitis C virus (HCV) is the main correlate of liver disease in patients with lichen planus (LP), mainly in southern Europe and Japan. However, a low prevalence of HCV infection has been found in LP patients in England and northern France, and significant differences in serum HCV RNA levels or HCV genotypes have not been found between LP patients and controls. Thus host rather than viral factors may be prevalent in the pathogenesis of HCV-related LP. The HLA-DR allele may influence both the outcome of HCV infection and the appearance of symptoms outside the liver.

OBJECTIVES

To assess whether major histocompatibility complex class II alleles play a part in the development of HCV-related LP.

METHODS

Intermediate-resolution DRB typing by hybridization with oligonucleotide probes was performed in 44 consecutive Italian oral LP (OLP) patients with HCV infection (anti-HCV and HCV RNA positive), in an age, sex and clinically comparable disease control group of 60 Italian OLP patients without HCV infection (anti-HCV and HCV RNA negative), and in 145 healthy unrelated Italian bone marrow donors without evidence of liver disease or history of LP and with negative tests for HCV.

RESULTS

Patients with exclusive OLP and HCV infection possessed the HLA-DR6 allele more frequently than patients with exclusive OLP but without HCV infection (52% vs. 18%, respectively; Pc (Pcorrected) = 0.028, relative risk = 4.93). We did not find any relationship between mucocutaneous LP, HCV infection and HLA-DR alleles.

CONCLUSIONS

HCV-related OLP therefore appears to be a distinctive subset particularly associated with the HLA class II allele HLA-DR6. This could partially explain the peculiar geographical heterogeneity of the association between HCV and LP.

The increasing problem of hepatitis C virus infection

The widespread incidence of hepatitis C (HCV) infection throughout the community is of concern. Although many of those infected will not suffer significantly from their infection, up to one-third will have liver disease, fatigue and oral health problems. General dental practitioners need to be aware of the precautions necessary in treating people with severe liver disease. This paper discusses the issues associated with treating patients who have HCV infection including the importance of preventive programs to reduce dental pathology and maximise oral health.

Celiac sprue: another autoimmune syndrome associated with hepatitis C

OBJECTIVE

Celiac sprue is being diagnosed with increasing frequency by screening individuals with epidemiologically associated autoimmune syndromes. We sought to test our hypothesis that hepatitis C also may predispose to celiac sprue because it can trigger autoimmune reactions.

METHODS

Two hundred fifty-nine consecutively evaluated patients with chronic hepatitis C infection, 59 with autoimmune liver disease, 137 with other hepatic diseases, 356 with various GI syndromes, and 221 normal volunteers underwent serologic screening for celiac sprue. Patients with antigliadin, antiendomysial, and antitissue transglutaminase antibodies in serum underwent duodenoscopy and biopsy.

RESULTS

There was a statistically significantly higher prevalence of antigliadin antibody in all groups of patients with liver disease compared with GI controls and normal controls. However, only patients with hepatitis C (n = 3; 1.2%) or autoimmune liver disease (n = 2; 3.4%) had antiendomysial/antitissue transglutaminase antibody in serum. One of 221 normal volunteers (0.4%) was antigliadin, antiendomysial, and antitissue transglutaminase positive; this individual also was found to have hepatitis C (previously undiagnosed). Each of these six individuals had mild intestinal symptoms, duodenal histopathology consistent with celiac sprue, and the celiac-associated HLA-DQ2 allele. Five of the six followed a prescribed gluten-free diet and experienced symptomatic improvement.

CONCLUSION

Celiac sprue is epidemiologically associated with chronic hepatitis C infection and with autoimmune liver disease. Because hepatitis C is much more frequently encountered than autoimmune liver disease, hepatitis C appears to be the most common hepatic disease associated with the development of celiac sprue.

Management of oral lichen planus

Lichen planus is a relatively common disorder of the stratified squamous epithelia. Most dental and medical practitioners see patients with lichen planus, but not all are recognized as having the disease. Patients with lichen planus may have concomitant involvement of the disease in multiple sites. Oral lichen planus lesions usually have a distinctive clinical morphology and characteristic distribution, but oral lichen planus may also present a confusing array of patterns and forms, and other disorders may clinically mimic oral lichen planus. The etiopathogenesis of lichen planus appears to be complex, with interactions between genetic, environmental, and lifestyle factors. Much has now been clarified about the etiopathogenic mechanisms involved and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory in all cases and there is as yet no definitive treatment that results in long term remission, but there have been advances in the control of the condition. Amongst the many treatments available, high potency topical corticosteroids remain the most reliably effective, though topical cyclosporine, topical tacrolimus, or systemic corticosteroids may be indicated in patients whose condition is unresponsive to topical corticosteroids.

Recent advances in diabetes mellitus of interest to dentistry

Significant changes were made in 1997 by The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus of the American Association of Diabetes regarding the diagnosis and classification of diabetes mellitus. The terms "insulin-dependent diabetes mellitus" (IDDM) and "non-insulin-dependent diabetes mellitus" (NIDDM) were dropped. The new classification is, in general, based on etiology rather than on treatment and includes four groups: Type I (autoimmune), Type 2 (non-autoimmune), Other specific types, and Gestational diabetes. The fasting blood glucose level for diagnosis was lowered from 140 mg/dL to 126 mg/dL. A random blood glucose of 200 mg/dL or greater in a patient with symptoms of diabetes is diagnostic. Each of these diagnostic tests needs to be repeated on a separate day. The glucose tolerance test is no longer recommended for routine diagnostic use. Recommendations for the screening of diabetes mellitus in presumably healthy individuals are presented. New advances in insulin and its delivery to the diabetic patient are discussed. The impact of diabetes mellitus on the oral cavity is updated.