Epstein-Barr Virus (EBV) Subtypes and Variants in Malignant Tissue from Malaysian Patients

Abstract

Epstein-Barr virus (EBV) is a ubiquitous virus that infects more than 90% of the world's population. In Malaysia this virus has been well documented in patients suffering from nasopharyngeal carcinoma, Hodgkin's lymphoma, and Burkitt's lymphoma. This study investigated the viral subtype and variant through the latent membrane protein-1 (LMP-1) gene taken from EBV-infected cancers in Malaysian patients. Nested polymerase chain reaction assays of EBV nuclear antigen-2 and single step polymerase chain reaction on the C-terminus of the LMP-1 gene were performed for virus typing and detection of a 30-bp deletion, respectively. Samples were obtained from 39 cases of nasopharyngeal carcinoma, 48 cases of Hodgkin's lymphoma, 19 cases of Burkitt's lymphoma and 19 cases of non-neoplastic reactive lymphoid tissues. All the tumors harbored EBV type A. Both the deleted and non-deleted variants were observed in the malignant tissues. In some cases, there was concurrent dual expression of both variants. Statistical analysis showed a significantly higher percentage of 30-bp deletions in cases of malignancies compared to reactive tissues. In conclusion, EBV type A predominates in Malaysian cancers, with a significant representation of the 30-bp deleted variant.