Epstein-Barr virus (EBV) infects most people at some point in their lives with 95 percent being EBV-positive by adulthood. Exposure usually occurs during childhood, and the infection is so mild that there are no symptoms. Some people will catch the virus when they’re teenagers or young adults, causing an illness known as infectious mononucleosis
In most normal adults, EBV is not associated with any symptoms or complications because the virus stays in hiding, living within the cell (known as latency). However, in a small percentage of people, this latent infection may eventually be associated with the development of certain disorders or even cancers. For some of these disorders, the virus causes the cells within the blood to proliferate uncontrollably (known as lymphoproliferative disorders). These disorders are not considered cancerous and may respond to treatment with anti-viral therapies. But in some cases, these diseases can be fatal.
EBV infection has been linked as a causative agent in some cancers, including Burkitt’s lymphoma, common in Africa and New Guinea, and nasopharyngeal carcinoma, common in China and southeast Asia. EBV may also cause malignancies seen in HIV-positive patients as well as patients who have recently undergone a transplant, as these patients are more susceptible to infections. Since the virus has been found in only about 40 percent of Hodgkin’s disease patients, the causation link between EBV and this cancer is unclear.
EBV has been linked to about one-third of all patients with Hodgkin’s disease. The exact role of the virus, which is found in Reed-Sternberg cells, in development of Hodgkin’s disease is not known.
If EBV is involved in certain cases of Hodgkin’s disease, that may provide new opportunities for treatment. One approach researchers are testing is to use gene therapy to trick the infected cells into making proteins that will kill them. Another approach in early clinical trials is to use drugs such as 5-azacytidine to force the virus out of hiding and into an active state that can be “seen” and eliminated by the immune system. Targeted drugs that interfere with proteins the virus needs to divide are also in development