Distribution of Epstein-Barr virus in the oral cavity of Thais with various oral mucosal conditions.

Objectives: We aimed to examine the presence of EBV, EBV strains, and variants among 3 oral conditions including normal oral mucosa (NOM), oral potentially malignant disorders/oral cancer (OPMDs/OC) and non-OPMDs/OC in a group of Thais. Material and methods: Oral exfoliated cells were obtained from 315 participants living in the northeastern and central regions of Thailand. The participants were divided into 3 groups encompassing the NOM, the OPMDs/OC and the non-OPMDs/OC groups. The presence of EBV was first determined by PCR using primers for LMP1 gene. Subsequently, EBV strains of EBNA3c and variants based on LMP1 sequences were determined by real-time PCR. Results: The prevalence of EBV in OPMDs/OC, non-OPMDs/OC and NOM were 72.0 %, 56.2 %, and 27.2 % respectively. EBV type A, B and AB were found in 52.1 %, 32.1 % and 15.8 % of all positive samples, respectively. The percentage of participants with EBV type A was more prominent in the NOM group (72.0 %) compared to the non-OPMDs/OC (54.8 %) and the OPMDs/OC group (41.8 %) whereas EBV type B was higher in the OPMDs/OC group (35.8 %) compared to the non-OPMDs/OC (31.5 %) and the NOM (24.0 %) groups. Regarding EBV variants, 30-bp deletion LMP1 variant (del-LMP1) which is more associated with malignant transformation was predominately found in the OPMDs/OC (32.8 %) and the non-OPMDs/OC (38.4 %) groups compared to the NOM group (20.0 %). Conclusions: High frequency of EBV was demonstrated in the OPMDs/OC group. EBV type A was more predominant in the NOM group whereas EBV type B was more prevalent in the OPMDs/OC group. The del-LMP1 variant was more common in the OPMDs/OC and the non-OPMDs/OC groups.

Analysis of Epstein-Barr Virus Infection in Oral Potentially Malignant Disorders and Oral Cancer: A Cross-Sectional Study.

Aims and Objectives: The primary objective of this study is to determine the prevalence of Epstein-Barr virus (EBV) in oral potentially malignant disorders (OPMDs) and oral cancer (OC) in a group of Thais using polymerase chain reaction (PCR) and Epstein-Barr encoding regions (EBERs) in situ hybridization (ISH). The secondary objective is to investigate the risk factors of OC and the association between the presence of EBV and risk factors of OC/site of oral lesions. Materials and Methods: Sixty-one participants attending the screening project for OC and OPMDs at the Northeastern district hospitals of Thailand were recruited. Information related to risk factors and biopsy tissues for histopathological diagnosis was collected. Sixty-seven paraffin tissue blocks, including 52 OPMDs and 15 OC specimens, were investigated for EBV infection, using PCR analysis with latent membrane protein-1 (LMP-1) primer and EBERs ISH. Pearson's Chi-square or Fisher's exact test was used to analyze the differences in variables between participants with OPMDs and OC, as appropriate. The association between EBV infection and related risk factors was analyzed using logistic regression with a significant level at 0.05. Results: Using PCR analysis, 8 of 67 specimens (11.94%) were positive for LMP-1. Three cases of OPMDs were positive for both LMP-1 PCR and EBERs ISH. Regarding risk factors of OC, the two most common risk factors were betel nut chewing (52.46%) and working in sunlight (42.62%). The habit of taking alcohol was significantly different between the OC and the OPMDs groups (p = 0.009). The association between LMP-1 and the lesion at the tongue was statistically significant, with odds ratio = 4.900 (95% confidence interval = 1.046-22.943; p = 0.044). Conclusions: The prevalence of EBV infection in this group of participants was low. However, OPMDs at the tongue exhibited a significant association with EBV infection.

Presence of Candida and its associated factors in participants attending oral cancer screening in the lower northeastern area of Thailand.

BACKGROUND: Certain evidence indicated high prevalence of Candida in oral potentially malignant disorders (OPMDs) and oral cancer (OC). This study was aimed to investigate the presence of Candida and its associated factors in participants who attended the oral cancer screening program in the lower northeastern districts of Thailand. METHODS: Convenient participants residing in the lower northeastern districts of Thailand who attended the oral cancer screening were enrolled. A questionnaire retrieving demographic characteristics, risk factors of oral cancer, and risk of having Candida was completed. Oral examination was performed by oral medicine specialists or oral surgeons. The participants were categorized into 4 groups according to their clinical diagnosis, namely normal oral mucosa (NOM), OPMDs/OC, non-OPMDs/OC and clinically suspected oral candidiasis (CSOC). Stimulated saliva flow rate was measured. Dip-slide test was performed in each participant to evaluate the presence of Candida. The levels of Candida were categorized into high and low levels according to the score received from the dip-slide test. Factors associated with high levels of Candida were identified using multivariate logistic regression analysis. RESULTS: A total of 577 participants were recruited. High levels of Candida were found in 31.3%, 24.7%, 25.9% and 18.1% in the OPMDs/OC, the non-OPMDs/OC, the CSOC and the NOM groups, respectively. According to multivariate logistic regression analysis, age above 60 years, female gender, betel quid chewing habit, use of denture, hyposalivation, and being in the CSOC group were found to be significantly associated with high levels of Candida. CONCLUSION: Higher number of participants in the OPMDs/OC group was found to have high levels of Candida. Increasing age, female gender, betel quid chewing habit, use of denture, hyposalivation and having CSOC lesions were associated with high levels of Candida.

Epstein-Barr Virus Detection and LMP-1 Expression in Thai Patients with Oral Squamous Cell Carcinoma.

BACKGROUND: To date, high-risk human papillomavirus (HPV) is primarily linked to oropharyngeal carcinoma, but only a small subset of oral squamous cell carcinoma (OSCC) is truly driven by high-risk HPV. In addition, Epstein-Barr virus (EBV) is another potential oncogenic virus for OSCC development. This study aims to investigate the role of EBV infection in Thai patients with OSCC. METHODS: Forty-seven formalin-fixed paraffin-embedded specimens of OSCC were obtained. EBV DNA was detected by polymerase chain reaction analysis using primers for LMP-1 region of EBV. EBV-positive OSCC cases were subjected to LMP-1 immunohistochemical analysis and EBV-encoded small RNA (EBER) in situ hybridization to determine EBV cellular localization in OSCC. LMP-1 immunohistochemical analysis was also performed in all EBV-negative OSCC cases. RESULTS: Of the 47 OSCC specimens, ten (21%) exhibited EBV DNA by PCR analysis. Seven of ten (70%) EBV-positive specimens showed high-grade LMP-1 expression by immunohistochemistry. However, no EBER expression was detected in all EBV-positive OSCC specimens. In EBV-negative specimens, LMP-1 was also negative except in 3 specimens which showed low grade expression of LMP-1. CONCLUSION: The prevalence of EBV infection in OSCC in this group of Thai patients was 21%. Most of EBV-positive OSCC cases showed LMP-1 expression but a lack of EBER expression. From our findings, we presume that EBV may take some roles in OSCC development in this group of participants.

Detection of Human Papillomavirus and p16INK4a Expression in Thai Patients with Oral Squamous Cell Carcinoma.

This study investigated the prevalence of human papillomavirus (HPV) infection in oral squamous cell carcinoma (OSCC) cases, as well as the association between HPV presence and p16INK4a expression, in Thai patients with OSCC. Eighty-one formalin-fixed paraffin-embedded specimens of OSCC were obtained. DNA extraction was performed; this was followed by nested polymerase chain reaction analysis to determine HPV DNA status, using consensus primers for the L1 region of HPV. HPV subtypes were determined by DNA sequencing. HPV-positive specimens and HPV-negative specimens from age- and sex-matched patients were subjected to immunohistochemical analysis to determine p16INK4a expression status. Of the 81 OSCC specimens, eight (9.9%) exhibited HPV DNA; DNA sequencing confirmed that the viral subtype was HPV-18 in all eight specimens. These eight HPV-positive specimens, as well as eight HPV-negative specimens from age- and sex-matched patients, were subjected to immunohistochemical analysis to determine p16INK4a expression status. Three of eight (37.8%) HPV-positive specimens and three of eight (37.8%) HPV-negative specimens showed positive p16INK4a expression findings. However, we did not find a significant association between HPV status and p16INK4a expression status in our OSCC samples. In conclusion, the prevalence of high-risk HPV was low in this group of OSCC patients; no association between HPV status and p16INK4a expression status was identified.

An Unusual Presentation of Multiple Superficial Mucoceles Occurring with Oral Lichen Planus.

Superficial mucoceles, a rare variant of the mucocele occurring simultaneously with oral lichen planus, are uncommon. This report introduces a case of multiple superficial mucoceles developing with oral lichen planus in a 76-year-old Thai female and provides information to avoid misdiagnosis and over-management of this lesion. Pathogenesis and clinicopathological characteristics of this phenomenon are also discussed.