(ORDO NEWS) — A treatment that targets a common virus lurking in our bodies could ease the worsening condition caused by multiple sclerosis (MS), according to new trials. Surprisingly, it can even reverse some of the symptoms.
Phase I clinical trials by California-based immunotherapy company Atara Biotherapeutics have confirmed that latent Epstein-Barr (EBV) infections are an effective treatment for MS in at least some patients, supporting a curious link between the virus and the deadly disease. that affects millions of people around the world.
Of the 24 volunteers who participated in the study, 20 showed signs of either improving or at least stopping the steady decline in health. It is important to note that no serious side effects were noted.
As promising as these results may seem, the study has yet to be peer-reviewed. Moreover, the path from small clinical trials to an approved drug is not easy. Years of research on larger and more diverse groups of volunteers are needed to uncover hidden risks or prove the effectiveness of treatments.
But there is every reason to believe that fighting the dormant virus could be the key to slowing down a particular aspect of MS – the progressive destruction of myelin, the “insulation” that protects nerve cells.
About 95 percent of people become infected with EBV at some point in their lives; this virus, also known as human herpesvirus 4, causes a disease known as mononucleosis, or glandular fever.
Symptoms are rarely severe, but the virus remains in the body, ready for possible future reactivation. The consequences of its reappearance range from benign to deadly, although most people do not notice if EBV reappears in the body.
However, studies have found speculated links between EBV and various autoimmune diseases, cancer, and chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).
Back in the early 1980s, medical researchers noticed that a large number of blood samples from people with multiple sclerosis had elevated levels of antibodies to the Epstein-Barr virus.
How the two diseases might be related remains an open question, although a recent longitudinal study published by Harvard scientists found that EBV infection “significantly increases the risk of subsequent development of multiple sclerosis.”
Another recent study by researchers at Stanford University found that nearly a quarter of MS patients have antibodies that bind to both an EBV protein called EBNA1 and a protein made by our own nervous system called the glial cell adhesion molecule, or GlialCAM.
“Part of the EBV protein mimics the host’s own protein – in this case GlialCAM, which is found in the insulating sheath of nerves,” says Stanford immunologist William Robinson.
“This means that when the immune system attacks EBV to clear the virus, it also targets GlialCAM in myelin.”
This loss of myelin may be the underlying cause of multiple sclerosis symptoms. They range from difficulty walking to cognitive dysfunction, numbness and tingling, and in some cases pain, vision problems, and even clinical depression.
Why EBV tricks the immune system of some people and not others is not known, although genetics may play some predisposing role, perhaps making it difficult for one’s own white blood cells to respond to repeated EBV infections.
If the constant presence of the virus causes some people’s immune systems to attack their own myelin, then helping clear the infection could help treat MS symptoms. This idea was first tested just under a decade ago by transplanting EBV-targeted immune cells into a 42-year-old patient.
Encouraged by the results of the experiment, scientists from Australia conducted a larger study in 2018 on 10 patients, taking their own T-cells from them and training them to hunt cells infected by the virus.
With seven out of 10 patients showing signs of improvement, an even larger and more rigorous clinical trial was required to really test the concept in practice.
Instead of using patients’ own cells in the latest trial, Atara Biotherapeutics used specially selected donor white blood cells, hoping this would provide a faster, “off-the-shelf” delivery system.
Called ATA188, this therapy, the authors hope, will not only give MS patients a chance to prevent EBV infection and thereby improve symptoms, but will also allow the “donor model” to be easily expanded to include more and more diverse patients.
The results of the team’s work were presented at a meeting with investors recently and at a conference at the end of last year. They stated that of the 18 patients who agreed to participate in the longer data collection period, nine reported a sustained improvement in disability for a year or more.
There have also been no reports of adverse immune responses, further proving the urgent need for continued research. Most interestingly, the study also assessed myelin repair.
Given the small sample size and modest improvements, the fact that there are hints of remyelination around some nerves is encouraging, as this is not something that is commonly seen in MS patients.
“Once a patient reaches a certain level of progressive disability, they rarely return to normal, and any improvement that persists would not be expected in the natural history of the disease,” says University of Ottawa neurologist Mark Friedman.
Because there are approximately 1 million people living with MS in the US alone, and the disease not only impairs quality of life but can shorten life expectancy by years, a treatment that can slow down the progression of the disease may not appear quickly enough.”
Contact us: [email protected]