Sunday, May 1, 2011

Uh Oh, Mono! Link of EBV and Hodgkin's

Last weekend, my aunt, an ER and college health center physician's assistant, was telling me about recent mononucleosis outbreaks at the college she works for. Mono is pretty common in college (I have quite a few friends who have succumbed to the "kissing disease"), so I wasn't very surprised by what she told me. However, she then brought up that there are new studies showing a link between mononucleosis, caused by the Epstein Barr Virus (EBV) and Hodgkin's disease. I did some more research and found that this information isn't all that recent.

In a 2000 study, Murray et. al. found coexpression of EBV RNAs with malignant Hodgkin's lymphoma cells (seen on the right, EBV RNAs are stained in brown and membrane proteins of the Hodgkin's cells are in red). This suggests that some of the EBV proteins are oncogenic.

This isn't the only study out there about mono and Hodgkin's disease. Some suggest that EBV is involved in the pathogenesis of Hodgkin's disease (link). A 2007 review article, nicely summarizes current views on EBV and Hodgkin's.

But what does this mean for all those college students who have now been exposed to the Epstein Barr Virus? Are they going to develop Hodgkin's later in life? Probably not. Exposure to EBV does increase a person's risk for Hodgkin's disease. An increased risk does not mean that the risk is absolute. The risk does increase for about 20 years after the initial infection. EBV does play a role in the pathogenesis of about half the cases of Hodgkin's disease. Only one in 1000 exposed with mono will develop HD.

This means that something else is required down the pathway to cause HD in addition to exposure to EBV. Still, the fact that a virus so common has a link to cancer is a pretty unnerving thought.