A study carried out by researchers at Cincinnati Children’s Hospital has discovered that the extremely common Epstein-Barr virus is a risk factor for seven diseases, including lupus and multiple sclerosis. The full story is available here, at PR Newswire.
A video discussing the findings can be found here.
The Epstein-Barr virus (EBV) affects almost everybody; over 90% of people worldwide catch the virus by the time they turn 20. The majority of people will not show any symptoms, and an even higher proportion will not realize they have it. However, a low proportion of people who catch EBV go on to develop a related disease, the most common of which is mononucleosis, or mono, which can last weeks and causes extreme tiredness. For an even smaller minority of people the virus may be linked to more serious disease. EBV has previously been connected to certain lymphatic cancers, and the recent study published in Nature Genetics shows that the virus also plays a role in seven other major diseases. These collectively affect almost 8 million people living in the US, and are:
- Systemic lupus erythematosus (SLE)
- Inflammatory bowel disease (IBD)
- Celiac disease
- Multiple sclerosis (MS)
- Juvenile idiopathic arthritis (JIA)
- Type 1 diabetes
- Rheumatoid arthritis (RA)
EBV increases the risk of these diseases through a genetic mechanism. When a person is infected with the virus their body produces an immune response that sends B cells to destroy the virus. While this works for most viruses, the EBV produces a protein known as EBNA2 that binds to DNA in the B cells and hijacks them.
The location at which the EBNA2 protein attaches itself to the genetic code can increase the risk of different diseases. If it attaches itself to certain areas connected to multiple sclerosis then the risk of that disease will rise, whereas other areas will link to other diseases. It is unclear at this stage how important the role of EBV infection is for each disease, although the researchers speculate that the virus plays a large role in multiple sclerosis and lupus in particular.
This discovery radically changes our understanding of the Epstein-Barr virus and the underlying causes of these diseases. One of the lead authors on the paper and the Director of CAGE at the Cincinnati Children’ Hospital, John Harley, MD, PhD, says,
“I’ve been a co-author in almost 500 papers. This one is more important than all of the rest put together.”
To further investigate the implications of this study, the researchers carried out an additional analysis of 1,600 proteins of the type involved in the EBV mechanism, and genetic variants linked to over 200 conditions. They found connections with 94 diseases.
