The Evidence of the Epstein-barr Virus Infection in Periapical Granulomas

Objectives: In late years, herpes virus such as Epstein-Barr virus (EBV) has been detected in periapical periodontitis lesions, but the details of localization and influence of EBV infection in periapical periodontitis are still unclear. Therefore, it is unknown whether EBV is really infected in periapical lesions. The objective of this study was to clarify detection and localization of the EBV infection in periapical periodontitis.
Methods: Surgically removed periapical lesions were analyzed by hematoxylin-eosin stains using the paraffin section. Only periapical granulomas were used in this study. Healthy gingival tissues were collected at the time of impacted wisdom teeth extraction. DNA was extracted from each sample, and EBV DNA was detected using real-time PCR. For statistical analysis, Mann-Whitney U test was used. Also, the paraffin sections which were confirmed the presence of EBV DNA were examined for Epstein-Barr virus encoded small RNA (EBER) using in situ hybridization. Serial section which showed EBER expression was analyzed for latent membrane protein 1 (LMP-1) by immunohistochemistry.
Results: Of 40 specimens, 32 specimens were histologically determined as periapical granulomas. EBV DNA was detected from 25 out of 32 periapical granulomas, whereas healthy gingival tissues never showed EBV DNA. EBER and LMP-1 were found at B cells and plasma cells in paraffin sections of periapical granulomas. Furthermore, the expression of LMP-1 and EBER was observed at the same site in the serial section.
Conclusions: Because EBV DNA was detected, and EBER which is a reliable marker of EBV infection and LMP-1 were found at B cells and plasma cells, we concluded that EBV infects in periapical granulomas.