The most common therapy for multiple sclerosis can increase the risk of a viral infection and the odds of a difficult recovery or even death from that infection. Now, scientists at the Oklahoma Medical Research Foundation have discovered a potential remedy.
In a four-year study with laboratory mice, Bob Axtell, Ph.D., and Susan Kovats, Ph.D., determined that a drug called interferon-beta could help.
“We wanted to replicate the vulnerability to a serious respiratory virus that MS patients often face,” Axtell said. “In our experiments, we gave the mice B cell depletion therapy, which is a prevalent MS treatment. Then we gave them the flu.”
B cells make antibodies that neutralize viruses. In MS and other autoimmune diseases, those B cells produce autoantibodies that attack healthy organs and tissues, mistaking them for outside invaders. These diseases cause inflammation and sometimes organ damage. B cell depletion therapy works by reducing the number of B cells that can mistakenly turn against the body.
In the OMRF study, Kovats and Axtell found that treating the immune-depleted mice with interferon-beta, which was approved as a therapy for MS in the 1990s, helped the animals recover from flu.
“Our study results surprised us,” Axtell said. “We’re still not sure exactly why interferon-beta helped mice with depleted B cells have a better outcome from influenza A.”
“B cell depletion is a great treatment for MS as long as the patient remains otherwise healthy,” Kovats said. “The biggest concern is when a novel virus like the one that causes Covid-19 comes around, there’s no vaccine for it and your B cells can’t do their job.”
Several studies during and after the pandemic examined the outcomes of people who contracted Covid-19 while on some form of B cell depletion therapy. In 2021, the Johns Hopkins University School of Medicine found that such people were nearly twice as likely as the general public to die of Covid-19. Those who lived generally required a far longer and more difficult recovery, the study showed.
OMRF physician-scientist Gabriel Pardo, M.D., is particularly interested in the study results. A neurologist and neuro-ophthalmologist, Pardo oversees the foundation’s Multiple Sclerosis Center of Excellence, which treats more than 3,000 MS patients.
“When the Covid-19 pandemic hit, one of our main concerns was how to protect patients who were immunosuppressed, specifically those on B cell depletion therapy,” Pardo said. “While more research is needed, the study by Drs. Axtell and Kovats gives us ammunition against a virus like Covid for patients in those circumstances.”
B cell depletion therapy often is used to treat other autoimmune diseases, including lupus and rheumatoid arthritis. “For that reason, this discovery provides an avenue to explore beyond MS,” Pardo said.
The research was published Wednesday in the Journal of Immunology and was funded by the Presbyterian Health Foundation.
