Human papillomavirus in premalignant oral lesions: No evidence of association in a Spanish cohort

Background

Human papillomavirus (HPV) is the cause of a fraction of head and neck squamous cell carcinoma. Although this relation is well-known, it is still not clear the role of HPV in premalignant oral lesions such as oral lichen planus (OLP) and dysplasia. We aimed to evaluate the HPV-DNA prevalence and type distribution in a set of oral biopsies obtained from patients diagnosed with OLP and dysplasia, as well as the role of HPV in these lesions.

Methods

A retrospective cohort of all premalignant oral lesions consecutively diagnosed from March 30^th 1995 to May 21^st 2014 at Hospital of Bellvitge and Odontological University Hospital of Bellvitge was identified and classified in four groups: OLP (groups 1 and 2) and dysplasias (groups 3 and 4) that progressed or not to invasive cancer during follow-up. A random selection targeting 25 cases was aimed to be performed for each group. All selected cases were subjected to pathological evaluation, DNA quality control and HPV-DNA detection. HPV-DNA positive samples were further subject to p16^INK4a analysis.

Results

A total of 83 cases yielded a valid HPV-DNA result. From those, 7 and 34 cases were OLP that progressed or not to invasive cancer during follow-up, whereas 24 and 18 cases were displasias that progressed or not to invasive cancer during follow-up, respectively. HPV-DNA was detected in 4 samples (3 dysplastic lesions and 1 OLP). Two samples were HPV16 positive (2%), 1 sample HPV18 positive (1%) and 1 sample (1%) was HPV indeterminate. Two out of four HPV-DNA positive cases had high p16^INK4a expression and none of the HPV positive cases progressed to invasive cancer during long-term follow-up.

Conclusions

We found a low HPV-DNA attributable fraction in premalignant lesions of the oral cavity, suggesting that HPV is unlikely to play a significant role in oral carcinogenesis in our setting.

The Magnitude of the Association between Human Papillomavirus and Oral Lichen Planus: A Meta-Analysis

Background

The role of human papilloma virus (HPV) in oral lichen planus (OLP) is controversial.

Objectives

The primary aim of the current study is to calculate the pooled risk estimates of HPV infection in OLP when compared with healthy controls.

Methods

Bibliographic searches were conducted in three electronic databases. Articles on the association between HPV and OLP were selected from case-control studies or cross-sectional studies, following predefined criteria. Pooled data were analyzed by calculating odds ratios (OR) and 95% confidence interval (CI).

Results

Of the 233 publications identified, 22 case-control studies met the inclusion criteria. Collectively, 835 cases and 734 controls were available for analysis. The summary estimate showed that OLP patients have significantly higher HPV prevalence (OR: 6.83; 95% CI: 4.15–11.27) than healthy controls. In subgroup analyses, the association of HPV and OLP varied significantly by geographic populations. The ORs ranged from 2.43 to 132.04. The correlation of HPV and erosive-atrophic oral lichen planus (EA-OLP) (OR: 9.34) was comparable and well above that of HPV and non-EA-OLP (OR: 4.32). Among HPV genotypes, HPV 16 showed an extremely strong association with OLP (OR: 11.27), and HPV 18 showed a relatively strong one (OR: 6.54).

Conclusion

In conclusion, a significant association was found between HPV and OLP. The strength of the association varied across geographic populations, clinical types of OLP, and HPV genotypes. The results suggest that HPV might play an important causal role in OLP and in its malignant to progression.

[Determination of human papillomavirus in oral leukoplakia,oral lichen planus and oral squamous cell carcinoma]

OBJECTIVE

To investigate the possibility for human papillomavirus (HPV) infection to be a predictable signal for the carcinogenesis of oral mucosa by comparing the prevalences of HPV in each stage of oral mucosal carcinogenesis and to compare the sensitivity differences of the two methods in detecting HPV infection in oral cavity.

METHODS

The hybrid capture (HC-II) was used to detect infection of HPV in 255 samples taken from 12 cases of healthy oral mucosa, 211 cases of patients with pathological diagnosis and 32 cases of patients with clinical diagnosis. The diagnosed cases included 8 cases of benign lesions of the oral mucosa, precancerous lesions [74 cases of oral leukoplakia (OLK) with hyperplasia and 42 cases of OLK with oral epithelial dysplasia (OED)], 91 cases of precancerous condition [oral lichen planus (OLP)] and 28 cases of oral squamous cell carcinoma (OSCC). And in situ hybridization (ISH) was used to detect infection of HPV in 33 cases of OSCC and 76 cases of OLK, including 30 cases of hyperplasia, 15 cases of mild OED, 15 cases of moderate OED and 16 cases of severe OED.

RESULTS

The prevalence of HPV in OLP samples was higher (12.12%, 8/66) than that of OLK (2.59%, 3/116) (χ(2)=4.666, P=0.031) and OSCC(7.14%, 2/28, χ(2)=0.513, P=0.474). The prevalence of HPV in OSCC (7.14%, 2/28) was higher than that of OLK (2.59%, 3/116), and no significant difference was found. There was only one case of smoke spot and statistical analysis was not carried out. ISH was used to detect type 16/18 and type 31/33 HPV DNA in 109 cases of oral mucosal lesions in paraffin sections and only one case of OSCC was HPV positive. Thirty-seven cases were detected by HC-II and ISH methods at the same time. The same negative results by the two methods were found in 94.6% samples (35/37). In the other two samples, one was OSCC with early infiltration and the other was OLK with hyperplasia, The HC-II results were positive while the ISH results were negative. The patients with OLP and HPV testing results were followed up and the average follow-up period was (36.2 ± 10.5) months. It was found that three of them had a malignant transformation, and the malignant transformation rate of HPV positive patients was 12.50% (1/8), which was higher than that of HPV negative patients (3.45%, 2/58), and the difference was not statistically significant, P=0.249.

CONCLUSION

HC-II assay was more sensitive in detecting HPV infection of oral mucosal lesions than ISH. The results of this study showed that there was insufficient evidence for taking HPV infection as a predictor of OLK carcinogenesis. Patients suffering from OLP were in a precancerous condition. The prevalence of HPV in OLP patients of this study was higher than that in OLK and OSCC patients, suggesting that for some reason, OLP patients were susceptible to HPV. HPV testing can be considered as routine in patients with OLP, and HC-II assay was recommended. And patients with OLP and HPV positive should be followed up regularly.

Role of human papilloma virus-16 in the pathogenesis of oral lichen planus--an immunohistochemical study

BACKGROUND

Oral lichen planus (OLP) is a common chronic inflammatory immune-mediated disease with an aetiopathogenesis associated with cell-mediated immunological dysfunction. It is possible that oral mucosal viral infections, including human papilloma virus-16 (HPV-16) infection, may have a causative role in OLP pathogenesis.

AIM

To assess the prevalence of HPV-16 in histopathologically diagnosed specimens of OLP and to evaluate whether any clinical features (such as the localisation of specimens) or the age or gender of patients, are correlated with the presence of this virus.

MATERIALS AND METHODS

This study was conducted on 30 specimens with a histopathological diagnosis of OLP, using the immunohistochemical marker HPV-16. Thirty normal oral mucosa specimens were also included as controls. Brown nuclear staining was accepted as positive for the HPV-16 antibody. The results were analysed using Fisher's exact test. P values<0.05 were considered to be significant.

RESULTS

Significant correlation (P=0.0001) was observed between HPV-16 infection and samples with OLP. No statistical conclusions could be drawn regarding age, gender, localisation and HPV-16 positivity.

CONCLUSION

Our study showed that HPV-16 may play a role in the pathogenesis of OLP. Taking into account the oncogenic potential of HPV-16, patients with OLP should be screened for the presence of this virus.

Oral manifestations of hepatitis C virus infection

Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV.

Brushing of Oral Mucosa for Diagnosis of HPV Infection in Patients with Potentially Malignant and Malignant Oral Lesions

INTRODUCTION

Adequate brushing of oral mucosa is important for accurate human papillomavirus (HPV) detection in potentially malignant (oral leukoplakia [OL], oral lichen planus [OLP]) and malignant (oral squamous cell carcinoma [OSCC]) lesions. Since various factors may limit the adequacy of oral brushing and, consequently, the accuracy of HPV detection, modified sampling procedures should be evaluated for their effect on HPV frequency and/or types detected.

AIM

To compare the HPV frequency in samples obtained by brushing the lesion site with the frequency in samples obtained by brushing an apparently normal adjacent site. The correlation between HPV frequency and keratinization of the site affected by the lesion, as well as sociodemographic variables (age, sex, smoking and drinking habits), was also examined.

METHODS

HPV DNA was detected in brushing samples from 50 patients with OL, 49 with OLP, and 17 with OSCC. Polymerase chain reaction (PCR) amplification was performed by MY09/MY11 and GP05+/GP06+ primers; the HPV type was identified by DNA sequencing and a reverse hybridization (line probe) assay. Data were analyzed by the Z test, the Fisher's exact test, the chi-square test, odds ratio (OR), and a logistic regression model.

RESULTS

HPV DNA was detected in 22% of samples from lesion sites and in 16% of samples from adjacent sites (p = 0.22) in patients with OL, in 24.5% and 22.4% of samples from lesion and adjacent sites, respectively, in patients with OLP (p = 0.40), and in 35.3% and 41.2% of samples from lesion and adjacent sites, respectively, in patients with OSCC (p = 0.36). Lesions adjacent to HPV-positive normal sites had an increased rate of HPV detection (OR = 30; 95% CI 9.57, 94.1). HPV-18 was the most frequent genotype, followed by HPV-6, -16, -33, and -53. HPV prevalence was reduced in lesions at keratinized sites (14.5%) compared with non-keratinized sites (34.4%; p = 0.007; OR = 0.32; 95% CI 0.13, 0.81).

DISCUSSION

In patients with OL, OLP, or OSCC, a high prevalence of HPV infection was shown in apparently normal sites adjacent to lesion sites infected by HPV. The lower HPV frequency in lesions at keratinized sites suggests that HPV detection by lesion brushing is affected by keratinization. The keratinized epithelium may be less susceptible to HPV infection or, alternatively, the highly proliferative activity in non-keratinized sites may predispose to HPV infection.

CONCLUSION

Results from this study indicate that taking samples from normal sites adjacent to oral lesions may be of value in HPV detection, particularly when the lesions are located at keratinized sites. This sampling procedure may allow more accurate diagnosis of HPV infection compared with sampling only the lesion site, and may also represent a reliable method to investigate the biological characteristics of HPV infection and related oral carcinogenesis.

Oral hairy leukoplakia arising in an oral lichen planus lesion in an otherwise immune-competent patient

Oral hairy leukoplakia (OHL) presents clinically as thickened white plaques which cannot be rubbed off, and is most often found on the lateral margin of the tongue. The name is derived from its often hairy appearance. OHL has clinical significance because of its association with HIV infection, and it is rare in immune-competent people. We report on a case of unilateral OHL which arose in an oral lichen planus lesion in an immune-competent patient.

Detection of human herpesvirus 6 in patients with oral chronic graft-vs-host disease following allogeneic progenitor cell transplantation

INTRODUCTION

Chronic graft-vs-host disease (cGVHD) is a major cause of morbidity in long-term survivors of allogeneic hematopoietic progenitor cell transplantation. Herpesviruses are involved in the occurrence and progression of various oral diseases.

AIM

The aim of this study was to investigate the role of human herpesvirus 6 (HHV6) in patients with oral manifestations of cGVHD.

MATERIALS AND METHODS

Peripheral blood and oral fluids (whole saliva, gingival crevicular fluid and parotid gland saliva) from 19 cGVHD patients, and 28 blood donors were examined for HHV6. Oral tissue samples were collected from 12 cGVHD patients and 12 healthy individuals. Nested polymerase chain reaction was employed to identify the HHV6.

RESULTS AND CONCLUSION

The virus was detected in whole saliva in 13 cGVHD patients (68%) and in 19 blood donors (67%). HHV6 was not identified in any of the gingival crevicular fluid and parotid gland saliva samples in cGVHD patients. In the control group 14.3% of both, four gingival crevicular fluid and four parotid gland saliva samples were positive. Two oral tissue samples of cGVHD patients were positive for HHV6. These results indicate that patients with oral manifestations of cGVHD and healthy individuals present high and similar incidence of HHV6 in blood and oral fluids. These data do not support the importance of HHV6 in oral lesions of cGVHD.

Biopsy vs. superficial scraping: detection of human papillomavirus 6, 11, 16, and 18 in potentially malignant and malignant oral lesions

BACKGROUND

Several epidemiologic studies have shown a broad variation in the prevalence of human papillomavirus (HPV) in oral precancerous tissues and oral carcinomas.

METHODS

Biopsies and superficial scrapes of lesions, clinically suspected of HPV infection, were taken from patients with potentially malignant and malignant oral lesions, and subject to HPV DNA detection by PCR-Southern blot analysis.

RESULTS

From 22 patients with potentially malignant and malignant lesions analyzed, 41% of the biopsies were HPV DNA positive, whereas 95-100% of the superficial scrapes were positive (McNemar, P < 0.0001). Clinical presumption of HPV infection detected 67% (P < 0.0001) of the HPV DNA positive cases compared with 48% (P < 0.0001) determined by cytology and histopathology. The prevalence of HPV 6, 11, 16 and 18 in the oral mucosa was studied in 59 individuals. While 9% of normal controls were HPV DNA positive, 100% of the patients with potentially malignant and malignant lesions were HPV DNA positive, and the prevailing genotype was HPV 16 followed by HPV 18.

CONCLUSIONS

The higher HPV DNA detection rate in superficial oral scrapes than in biopsies suggests that accurate epidemiological information on oral HPV infection/oral carcinogenesis depends not only on the DNA detection technique, but also on the tissue/cell sampling procedure.

Oral lichen planus and hepatitis C virus: is there real association?

Lichen planus is an inflammatory, mucocutaneous disease that in addition to the skin involves oral mucosa in about 60-70 % of cases. In recent years, several reports have supposed a relationship between oral lichen planus (OLP) and chronic liver disease, especially hepatitis C (HCV). Here we present an extensive review of the literature in English that examines the association between HCV and OLP.

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.

Valuation of exfoliative cytology as prediction factor in oral mucosa lesions

The aim of this study was immunolabeling oncoproteins Ck14, p53, p21 and Bcl-2 in order to evaluate their expression in premalignant and malignant stomatological lesions in oral epithelial, and to compare this expression with exfoliative cytology alterations in the same patients. It was studied biopsies and cytologies of 13 subjects with oral lichen planus, with or without Human Papilloma Virus (HPV), leukoplakia and squamous cell carcinoma clinically diagnosed and confirmed by anatomopathological studies. The oral lichen planus lesion presented binuclei orange cells; and in leukoplakia lesions only orange stained was observed; meanwhile koilocytes, inflammatory cells, enlarge nuclear volume and pathogenic microorganisms were observed in the HPV infections and squamous cells carcinoma (SCC). The Ck14, p53, p21 and Bcl-2 proteins were found modified in the leukoplakia, oral lichen planus and cancer. Cytological alterations and positive immunolabeling or over-expression of Ck14 cytokeratine in the upper epithelial stratus should be indicator of malignant transformations as doing subsequence exams.

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.

Lichen planus and hepatitis C virus: a multicentre study of patients with oral lesions and a systematic review

BACKGROUND

An association between hepatitis C virus (HCV) infection and lichen planus (LP) has been investigated, but results have been inconsistent.

OBJECTIVES

To investigate the relationship between LP and HCV seropositivity. Methods In a cross-sectional study we tested the sera of 303 consecutive newly diagnosed patients with histologically proven LP referred to three Italian centres for the presence of anti-HCV IgG. A comparable control group was also tested. Next, in a systematic review, studies were identified by searching different databases in April 2004. Inclusion criteria were: (i) analytical study design; (ii) clinical and histological diagnosis of LP; and (iii) serological test for anti-HCV antibodies as main outcome. The risk of bias was assessed on the basis of characteristics of the study group, appropriateness of the control group and study design. Pooled data were analysed by calculating odds ratios (ORs), using a random effects model.

RESULTS

In the cross-sectional study, nearly one in five (19.1%) of the LP group was HCV positive, while a much lower prevalence of infection was found in the control group (3.2%) [OR 7.08; 95% confidence interval (CI) 3.43-14.58]. The systematic review yielded 25 relevant studies, six of which had a low risk of bias. There was a statistically significant difference in the proportion of HCV-seropositive subjects among patients with LP, compared with controls (OR 4.80; 95% CI 3.25-7.09). Following subgroup analyses, the variability of HCV prevalence in patients with LP seemed to depend on geographical area, but not on age.

CONCLUSIONS

Anti-HCV circulating antibodies are more common in patients with LP than in controls, although such an association may not be significant in some geographical areas.

Functions of the cytokines in relation oral lichen planus-hepatitis C

BACKGROUND

Lichen planus (LP) is a chronic common mucocutaneous inflammatory disorder of uncertain aetiology. An association between hepatitis C virus (HCV) infection and LP has been recognised, particularly in Italy, Spain and Japan. The pathogenesis of such an association is unclear, but it may be due to cell-mediated cytotoxicity to an epitope shared by HCV and damaged keratinocytes. Recent studies using in situ hybridization suggest that HCV may replicate in the oral mucosa.

OBJECTIVES

The aim of the present study was to examine the oral epithelium of patients with oral LP for evidence of HCV-RNA by polymerase chain reaction (PCR) and to examine the relationship to cytokines including interferon (INF-gamma), interleukins (IL-1, IL-2, IL-4, IL-6, IL-8 , and IL-10), tumour necrosis factor (TNF-alpha) and transforming growth factor (TGFbeta-1).

PATIENTS/METHODS

We selected 100 Italian patients, and divided them into 4 groups. Group A consisted of 25 HCV+ve patients with erosive oral LP. Group B was a control group constituted by 25 healthy HCV -ve subjects with no LP. Group C consisted of 25 HCV-ve patients with oral reticular LP and Group D was made of 25 HCV-ve patients with oral erosive LP. The patients of group A (test group) were submitted to oral biopsy with 2 samples of epithelium, lesional and non-lesional, and a 10 ml peripheral blood sample was taken. The patients of group B (negative control), C and D (comparison groups) were submitted to oral epithelial biopsy and a 10 ml peripheral blood sample was collected. PCR was used to search for HCV-RNA in biopsy material. Cytokines INF-gamma ,IL-1, IL-2, IL-4, IL-6, IL-8 , IL-10 and TNF-alpha and TGFbeta-1 were assayed in serum.

RESULTS AND CONCLUSIONS

PCR did not detect the viral genome in oral epithelium of the patients with oral LP and HCV+ve (group A), but there was an increase in levels of TNF-alpha and a reduction of IL-1, INF-gamma and IL-8 compared to patients who had oral reticular LP but HCV-ve and to patients who had oral erosive LP but HCV-ve, and compared to negative controls. The results indicate that patients of group A showed a reduction of pro-inflammatory but an increase in immunomodulant cytokines. The results suggest the possibility that HCV exerts an indirect effect, mediated possibly by the induction of cytokines and lymphokines.

[The influence of HCV infection and immunomodulating therapy (interferon-alpha and ribavirin) on the condition of minor salivary glands and oral mucosa]

The aim of the study was to determine an influence of HCV infection and combination therapy with interferon - alpha and ribavirin on the condition of oral mucosa and minor salivary glands in patients with chronic hepatitis C in comparison to subjects without liver pathology on 12-month follow-up. Patients with chronic hepatitis C more commonly develop pathological changes on the oral mucosa than patients without liver pathology. Combination therapy affects the amount of pathological lesions in the oral cavity of patients suffering from chronic hepatitis C and B. The occurrence of oral lichen planus on the oral mucosa may be associated with chronic hepatitis C as well as with concomitant alpha-interferon and antiviral therapy.

HPV DNA in clinically different variants of oral leukoplakia and lichen planus

OBJECTIVES

Our objectives were to determine the prevalence of human papillomavirus (HPV) infection in oral leukoplakia (OL) and oral lichen planus (OLP) in comparison with that in healthy oral mucosa, also conditionally to age, gender, smoking, and drinking habits of patients, so as to investigate any possible association of HPV infection with a specific clinical variant of OL or OLP.

STUDY DESIGN

We did research on HPV DNA in 68 cases of OL (homogeneous form [H] in 45 cases and nonhomogeneous form [non-H] in 23 cases), and in 71 cases of OLP (nonatrophic/erosive form [non-AE] in 27 cases, atrophic/erosive form [AE] in 44 cases). HPV DNA was investigated in exfoliated oral mucosa cells by nested PCR (nPCR: MY09-MY11/GP5-GP6) and the HPV genotype determined by direct DNA sequencing.

RESULTS

HPV DNA was found in 17.6% of OL, in 19.7% of OLP, and in 5.6% of controls, with a statistically significant higher risk of HPV infection in both lesion groups (for OL: P=.01; Odds Ratio [OR]=3.64; 95% CI: 1.21-10.80; for OLP: P=.005; OR=4.17; 95% CI: 1.41-12.18). Demographic variables analysis showed that the only significant association was between HPV status and current smoking in OL patients (OR'=3.40; 95% CI: 1.0-11.59). HPV DNA was found in 20% of H OL and 13% of non-H OL, without any association with the clinical variant (P=.73; OR=0.60; 95% CI: 0.14-2.48). HPV DNA was found in 18.5% of non-AE OLP and 20.4% of AE OLP, without any significant association with the clinical variant (P=.84; OR=1.13; 95% CI: 0.335-3.816). HPV-18 was the most frequently detected genotype (9/12 and 10/14 of HPV-positive OL and OLP, respectively), followed by HPV-16 (2/12 OL and 2/14 OLP), HPV-33 (1/12 OL), HPV-31 (1/14 OLP), and HPV-6 (1/14 OLP).

CONCLUSIONS

An increased risk of HPV infection was found in OL and OLP; however, no specific clinical variant of OL or OLP was noted to be associated with HPV infection. It is not possible to predict the likelihood of HPV infection from the clinical features of OL and OLP.

Hepatitis C virus and lichen planus

Hepatitis C virus (HCV) is an important factor in the development of chronic liver disease and hepatocellular carcinoma. In recent years it has become known that HCV induces various extrahepatic manifestations including mixed cryoglobulinemia, membranoproliferative glomerulonephritis, Sjögren's syndrome, autoimmune thyroiditis, malignant lymphoma, porphyria cutanea tarda and lichen planus. Although the mechanisms of extrahepatic manifestations remain unclear, it is known that interferon (IFN) therapy and coadministration of IFN with ribavirin are effective in promoting the disappearance or alleviation of such extrahepatic lesions, which have tended to be overlooked. The present review focuses on lichen planus, one of the major extrahepatic manifestations.

Hepatitis C virus and lichen planus: A review

INTRODUCTION

The relationship between hepatitis C virus (HCV) infection and oral lichen planus (OLP) remains a matter of controversy. It is important to determine whether there is an association between OLP and HCV infection so that guidelines regarding the routine HCV testing of patients with OLP can be developed for clinicians.

OBJECTIVES

The objective of this article was to review and summarize the published literature on the association between OLP and HCV and to describe future directions.

METHODS

A search of the computerized database MEDLINE (1966-June 2003) was conducted. The bibliographies of articles identified by means of MEDLINE were also searched. Any studies reporting the prevalence of HCV in a group of patients with LP either with or without a control group were included in this review. Also included were studies comparing the clinical and histologic features of LP among patients with and without HCV infection, studies on the presence of HCV within LP lesions, and studies of HCV genotypes among patients with LP.

RESULTS

Thirty-two studies conducted in various parts of the world were identified. Study types included prevalence studies on HCV exposure among patients with OLP (0%-62%), prevalence of OLP among patients with HCV infection (1.6%-20%), and case-control studies of this association. In addition, the results from 3 studies on the replication of HCV in the oral mucosa, 3 studies on the genotype of HCV in OLP patients, and 4 studies comparing the clinical and histologic features of OLP in HCV-infected and uninfected individuals have been summarized.

CONCLUSION

At present, studies on the association of OLP and HCV provide enough information to raise a number of interesting questions about this association. Important biases-including selection bias; investigator bias due to lack of blinding and the possible resultant nondifferential misclassification of disease; and possible confounding by age in the studies published-make it difficult to draw firm conclusions. However, the need for future studies that take into consideration all these factors in the study methodology is highlighted by this review.

Investigation into a possible association between oral lichen planus, the human herpesviruses, and the human papillomaviruses

BACKGROUND

Oral lichen planus (OLP) is a chronic relapsing cell-mediated condition of unknown etiology. The purpose of this study was to ascertain if the human herpesviruses (HHVs) or human papillomaviruses (HPVs) act as possible factors or co-factors in the pathogenesis of OLP.

METHODS

Thirty-eight histologically confirmed OLP and 20 normal control buccal mucosa tissue samples were analyzed. Polymerase chain reaction analysis was employed to detect members of the HHV and HPV families.

RESULTS

The Epstein-Barr virus and HHV-7 were detected in a small percentage of tissue samples. However, HPV-16 was detected in 26.3% of OLP samples and 0% of the normal control tissues. The epidermodysplasia verruciformis-related HPV types were detected in 42% of OLP samples and 45% of normal control samples.

CONCLUSION

The results of this study do not suggest a causative role for members of the HHV family in the pathology of OLP. However, a statistical association was found between HPV-16 presence and OLP.

Human papillomavirus 6/11, 16 and 18 in oral carcinomas and benign oral lesions

We have examined 118 oral squamous cell carcinomas, 72 oral leukoplakias, 12 cases of cheilitis and 65 of oral lichen planus for the presence of human papillomavirus (HPV) 6/11, 16 and 18 DNA by PCR/Southern blot hybridization. HPV DNA were found in 51/118 carcinomas (43.2%), in 16/72 (22.2%) leukoplakias, 3/12 (25.0%) cheilitic lesions and 10/65 (15.4%) lichen planus cases. These differences were even stronger when analyzing separately for the high-risk types HPV 16 and 18 as compared to low-risk types 6/11. HPV 16 and 18 DNA were present in 41/118 (34.7%) oral carcinomas, 12/72 (16.7%) leukoplakias, 2/12 (16.7%) cheilitic lesions and 6/65 (9.2%) lichen planus. In contrast to this, oral carcinomas displayed the lowest HPV 6/11 detection rate (4.2%), compared with 11.1% for leukoplakias, 8.3% for cheilitic lesions and 7.7% in lichen planus. These results indicate a successive increase of the detection rate of HPV 16 and 18 from low level in non or questionably preneoplastic lesions (lichen planus) to preneoplastic lesions (leukoplakia and cheilitis) and to oral carcinoma. In conclusion, our results suggest an association of oral carcinogenesis and infection with the high-risk HPV types 16 and 18.

Oral diseases possibly associated with hepatitis C virus

Morbidity associated with hepatitis C virus (HCV) infection can involve a variety of extrahepatic conditions, including lichen planus (LP) and sialadenitis, predominantly or exclusively involving the oral region, conditions which have been largely neglected in reviews. The literature suggests that HCV-infected patients may frequently have Sjögren-like sialadenitis with mild clinical symptoms, whereas oral LP may be significantly associated with HCV infections in Southern Europe and Japan but not in Northern Europe. These geographical differences could be related to immunogenetic factors such as the HLA-DR6 allele, significantly expressed in Italian patients with OLP and HCV. Analysis of experimental data suggests that HCV could be involved in the pathogenesis of both these diseases. Moreover, parotid lymphoma may arise in patients with sialadenitis, mainly with type II cryoglobulinemia. Little attention has been paid to oral health needs in HCV-infected patients and the variable effect of interferon-alpha therapy on oral tissues. Further research is needed, because of the potentially great influence of oral diseases possibly linked to HCV on the quality of life of millions of patients.

Oral lichen planus pathogenesis: A role for the HCV-specific cellular immune response

Hepatitis C virus infection can be associated with different extrahepatic manifestations, including lichen planus; however, no clear role for HCV in their pathogenesis has been established. T cells were isolated from lichen biopsy specimens of 7 HCV positive patients with oral lichen planus. HCV-specific CD4(+) T-cell lines were obtained in 4 patients from lichen lesions but only in 2 of them from the peripheral blood. Different clonal populations were found in oral tissue and peripheral blood of individual patients, as shown by TCR-Vbeta analysis of antigen-specific T cells. Frequency of HCV-specific CD8(+) cells tested with 4 different HCV tetramers was significantly higher in the lichen tissue than in the circulation; moreover, lichen-derived HCV-specific CD8(+) T cells showed the phenotype of recently activated T cells because most of them were CD69(+) and produced interferon gamma (IFN-gamma) but expanded poorly in vitro upon antigen stimulation. The specificity of HCV-reactive T-cell recruitment into the lichen tissue was further confirmed by the absence of HBV-specific T cells within lichen lesions in 3 additional patients with lichen planus associated with HBV infection. Our study shows HCV-specific T-cell responses at the site of the lesions of an HCV-associated dermatologic disease, sustained by HCV-specific T cells with phenotypic and functional characteristics of terminally differentiated effector cells. In conclusion, this finding and the detection of HCV RNA strands in the lichen tissue strongly suggest a role for HCV-specific T-cell responses in the pathogenesis of oral lichen planus associated with HCV infection.