Epstein-Barr virus-encoded small RNAs (EBER)


EBER stands for Epstein-Barr virus-encoded small RNAs. These are small, non-coding RNAs produced by the Epstein-Barr virus (EBV), a member of the herpesvirus family.

EBERs are among the most abundant viral RNAs present in EBV-infected cells. There are two main types, EBER1 and EBER2. Despite their high abundance in EBV-infected cells, the exact functions of EBERs are not fully understood. They are believed to play roles in modulating the host immune response and maintaining viral latency.

What causes a cell to produce EBER?

A cell produces EBER when it is infected with the Epstein-Barr virus (EBV). EBV can infect different types of cells, but it predominantly infects B cells (a type of white blood cell) and epithelial cells. Once EBV infects a cell, it integrates its DNA into the host cell’s DNA, directing the cell to produce viral proteins and RNAs, including EBERs.

Medical conditions associated with EBER

The presence of EBER is closely associated with several types of cancers and lymphoproliferative disorders, as well as other conditions, including:

  • Hodgkin’s lymphoma: A type of lymphoma where EBER expression can be detected in the Reed-Sternberg cells, the characteristic tumor cells.
  • Nasopharyngeal carcinoma: A cancer originating in the nasopharynx, where EBER is commonly found in tumor cells.
  • Burkitt’s lymphoma: Particularly the endemic form found in Africa, where there is a strong association between EBV infection and EBER expression.
  • EBV-positive diffuse large B cell lymphoma: An aggressive type of lymphoma consisting of B cells that have been infected by EBV.
  • Post-transplant lymphoproliferative disorder (PTLD): A condition that can occur after organ transplantation due to immunosuppression, where EBER-positive cells indicate EBV’s role in the disease.
  • Plasmablastic lymphoma: A rare and aggressive form of lymphoma associated with both immune suppression and EBV infection.
  • NK/T cell lymphoma: An aggressive type of lymphoma that often involves the nasal cavity made up of both NK cells and T cells.
  • Stomach cancer: Some studies have shown an association between EBV infection, indicated by EBER expression, and certain types of stomach cancer.

How do pathologists test for EBER and why?

Pathologists test for EBER using in situ hybridization (ISH). This technique involves using a labeled probe that specifically binds to the EBER RNA present in the cells of a tissue sample. The presence of the probe can then be visualized under a microscope, indicating EBV infection.

Testing for EBER is important for several reasons:

  • Diagnosis: It helps confirm the diagnosis of EBV-associated diseases and cancers.
  • Prognosis: The presence of EBER in certain conditions, like Hodgkin’s lymphoma, can provide prognostic information.
In situ hybridization showing cells expressing EBER (brown cells).
In situ hybridization showing cells expressing EBER (brown cells).

About this article

Doctors wrote this article to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

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