FRIDAY, Nov. 14, 2025 (HealthDay News) — One of humanity’s most common viruses is behind the autoimmune disorder known as lupus, according to a new study.
Epstein-Barr virus (EBV) resides silently in the bodies of 19 in 20 Americans, and most often causes mononucleosis among teenagers and young adults, researchers said.
But the virus can cause a tiny number of immune cells to go rogue, starting a cascade that leads to widespread lupus attack on a patient’s skin, joints and internal organs, researchers reported Nov. 12 in Science Translational Medicine.
“This is the most striking finding to come out of my laboratory in my entire career,” lead researcher Dr. William Robinson, a professor of immunology and rheumatology at Stanford Medicine in California, said in a news release. “We believe it applies to 100% of lupus cases.”
About 1.5 million Americans suffer from lupus, according to the Lupus Foundation of America. Lupus causes the immune system to begin attacking a person’s cells, causing damage throughout the body.
For unknown reasons, 9 out of 10 lupus patients are women, the researchers noted.
Most people become infected with Epstein-Barr virus when they reach adulthood, by sharing a spoon, drinking from the same glass or exchanging a kiss, the researchers said.
“Pretty much the only way to not get EBV is to live in a bubble,” Robinson said. “If you’ve lived a normal life,” the odds are almost 20 to 1 that you have it.
Once a person contracts EBV, it takes up residence in infected cells, remaining dormant for the rest of a person’s life, the researchers said.
One type of cell that EBV takes up residence in are immune cells known as B cells, which produce antibodies in response to infection and encourage other immune cells to attack and kill invading viruses and bacteria.
Using a high-precision genetic sequencing system, the research team discovered that this is a rare occurrence. Less than 1 in 10,000 of an EBV-infected but otherwise healthy patient’s B cells harbor inactive EBV.
But lupus patients have a 25-fold higher level of EBV-infected B cells, with a fraction of 1 in 400.
The latent virus pushes the B cell where it remains dormant to produce a viral protein called EBNA2, the researchers said. This protein acts as a switch that activates a battery of genes in the B cell, including some that cause inflammation.
The net result: The B cell becomes highly inflammatory and begins to trigger other types of immune cells to attack healthy cells, the researchers said.
Robinson suspects that this cascade could extend beyond lupus to other autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and Crohn’s disease, which have previously been linked to the Epstein-Barr virus.
However, one question remains unanswered: If almost everyone has latent EBV in some of their B cells, why do only some of us develop lupus?
Robinson speculates that certain strains of EBV might be more likely to cause infected B cells to go rogue and begin the cascade that ends in lupus.
This discovery could lead to a cure for lupus, the researchers noted.
One approach being explored involves a process called ultradeep B cell depletion, in which all of a person’s circulating B cells are removed. Over the next few months, the person’s bone marrow would replace them with new EBV-free B cells.
More information
The Cleveland Clinic has more information about Epstein-Barr virus.
SOURCE: Stanford Medicine, press release, November 12, 2025
