Mystery Cause Of Lupus Revealed, Experts Say

Key TakeawaysOne of the most common human viruses is linked to lupusEpstein-Barr virus is most commonly associated with mononucleosisBut researchers found it can start an immune cascade that ends in lupus.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 out of 20 Americans, most commonly causing mononucleosis among teens and young adults, researchers said.But the virus can cause a minuscule number of immune cells to go rogue, starting a cascade that leads to lupus’ widespread assault on a patient’s skin, joints and internal organs, researchers reported Nov. 12 in Science Translational Medicine.“This is the single most impactful finding to emerge from my lab in my entire career,” senior researcher Dr. William Robinson, a professor of immunology and rheumatology at Stanford Medicine in California, said in a news release. “We think it applies to 100% of lupus cases.”Around 1.5 million Americans suffer from lupus, according to the Lupus Foundation of America. Lupus causes the immune system to start attacking a person’s cells, resulting in damage throughout the body.For unknown reasons, 9 of 10 lupus patients are women, researchers noted.Most people become infected with Epstein-Barr virus by the time they’ve reached adulthood, from sharing a spoon, drinking from the same glass or exchanging a kiss, researchers said.“Practically 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 nearly 20 to 1 you’ve got it.Once a person gets EBV, it takes up residence in infected cells, lying dormant for the rest of a person’s life, researchers said.One type of cell where EBV sets up shop is the immune cells known as B cells, which produce antibodies in response to infection and encourage other immune cells to target and kill invading viruses and bacteria. Using a high-precision genetic sequencing system, the research team found that this is a rare occurrence. Fewer than 1 in 10,000 of an EBV-infected but otherwise healthy patient’s B cells host dormant EBV.But lupus patients have a 25 times higher level of EBV-infected B cells, with a fraction of 1 in 400.The latent virus nudges the B cell in which it lies dormant to produce a viral protein called EBNA2, researchers said. This protein performs 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 starts prompting other types of immune cells to attack healthy cells, researchers said.Robinson suspects this cascade might extend beyond lupus to other autoimmune diseases like multiple sclerosis, rheumatoid arthritis and Crohn’s disease, which have previously been linked to the Epstein-Barr virus.However, one question remains unanswered: If nearly everyone has latent EBV in some of their B cells, why do only some of us develop lupus?Robinson speculates that certain EBV strains might be more likely to cause infected B cells to go rogue and start the cascade that ends in lupus.This discovery could lead to a cure for lupus, 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 killed off. Over the following months, the person’s bone marrow would replace them with new, EBV-free B cells.More informationThe Cleveland Clinic has more on Epstein-Barr virus.SOURCE: Stanford Medicine, news release, Nov. 12, 2025 .What This Means For YouLupus is tied to Epstein-Barr virus, which could help doctors find a cure..Sign up for our weekly HealthDay newsletter

Mystery Cause Of Lupus Revealed, Experts Say

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