Human Herpesvirus-6 and Epstein–Barr Virus Infections at Different Histopathological Grades of Oral Squamous Cell Carcinomas

BACKGROUND: The aim of this study was to determine the prevalence and viral load of Epstein–Barr virus (EBV) and Human herpesvirus-6 (HHV-6) in different histopathologic grades of oral squamous cell carcinoma (OSCC). METHODS: Forty-five formalin-fixed paraffin-embedded tissue section of OSCC patients were analyzed by quantitative real-time polymerase chain reaction for detection of EBV and HHV-6. RESULTS: The mean age of the patients was 58.6 years, 69% of whom were female, and 31% were male. Overall, the positive rate for EBV and HHV-6 were 16.7% and 27.1%, respectively; and the mean viral load EBV was 27.9 × 10(3) and 38.5 × 10(3) for HHV-6. No correlation was demonstrated between the viral load of EBV DNA (P = 0.35) and HHV-6 (P = 0.38) at the different OSCC histopathologic grades. CONCLUSIONS: These findings neither lend support to the hypothesis that EBV and HHV-6 are directly involved in OSCC nor rule out the possibility that these viruses play an indirect role in carcinogenesis in this area.