Stem cell injections could be the key to curing MS

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Your immune system is supposed to be the guardian of your health, defending you against germs and helping you heal from illness or injury, but that’s not the case for the more than 1.8 million people worldwide living with multiple sclerosis (MS).

Their immune systems attack their brains, spinal cords, and other parts of the central nervous system. This causes inflammation and damages myelin, a fatty substance that surrounds and protects nerve cells while also helping them transmit electrical impulses.

In the early stages of MS, most people experience periods of symptoms — such as pain, vision problems, and muscle spasms — followed by periods of remission. In the later stages, symptoms during attacks get more severe, and periods of remission become shorter and less frequent. 

In serious cases, patients may experience blindness or paralysis, and while MS is rarely fatal by itself, the average life expectancy for people with it is about 7 years shorter than the general population, often due to complications from the disease.

Researchers aren’t entirely sure what causes MS — it appears to be some combination of genetics, environment, and infection — and while there are treatments that can reduce the frequency and severity of attacks and slow the disease’s progression, there’s no cure for MS.

That could soon change, though, as researchers are honing in on ways to halt the progression of MS and maybe even prevent it altogether.

“Curing MS is within our reach,” Bruce Bebo, executive VP of research at the National MS Society, said in 2022. “And when we talk about curing MS, we’re talking about curing MS for everyone.”

Stem cell therapy

Most of your cells are specialized, meaning they serve a very specific role in your body. Stem cells, however, have yet to develop into a specific type of cell — if your body were a college campus, they’d be the freshmen who’ve yet to declare a major.

By placing stem cells in the right environment, scientists can coax them into developing into specific specialized cells — this ability has led to promising treatments for epilepsy, heart disease, Parkinson’s, and more.

The nervous system has its own type of stem cells — neural stem cells — and a team at the University of Cambridge found that injecting those stem cells into the brains of mouse models of MS reduces inflammation and could potentially even repair damage to myelin.

That group has now published the results of the first trial testing the treatment in people. 

“The results are very strong and very consistent.”

Stefano Pluchino

The small trial included 15 patients with secondary progressive multiple sclerosis (SPMS), meaning their disease was already in an advanced stage. Researchers injected neural stem cells directly into the patients’ brains, who then took immunosuppressant drugs for six months to prevent rejection.

The stem cell injections didn’t appear to cause any serious adverse effects during 12 months of follow up, suggesting that the treatment is safe. None of the participants saw a worsening of symptoms or an increase in disability after treatment, and measurements of their brain volume indicate that the stem cells may have reduced inflammation.

While larger, placebo-controlled trials are needed to confirm the treatment’s efficacy, these findings suggest that stem cell injections may be able to halt the progression of MS in its advanced stages.

“We don’t know yet whether this is the beginning of a fantastic journey or not, but the results are very strong and very consistent,” co-lead researcher Stefano Pluchino told the Guardian.

Gut check

While the Cambridge team focuses on the brain, researchers at the University of Virginia (UVA) are looking for a cure for MS in the gut microbiome, the collection of microbes that live in the human digestive tract and play an important role in our health.

In February 2023, they published a study detailing their discovery that a protein called AHR appears to trigger the production of inflammation-causing compounds in the guts of mouse models of MS.

They then demonstrated that they could decrease this inflammation by blocking the ability of the immune system’s T-cells to express AHR in the rodents’ guts.

“We are approaching the search for multiple sclerosis therapeutics from a new direction,” said lead researcher Andrea Merchak. “By modulating the microbiome, we are making inroads in understanding how the immune response can end up out of control in autoimmunity. We can use this information to find early interventions.”

More research is needed to find out whether blocking AHR in this way is safe and effective in people with MS, but it’s just one of many gut-based leads in the hunt for new MS treatments.

In 2022, a team led by UC San Francisco scientists identified dozens of differences between the gut microbiomes of healthy individuals and those with MS, and any one of those differences could be the basis for a future treatment or cure for MS.

Epstein-Barr virus vaccines

While the exact cause of MS is unknown, there is strong evidence that the Epstein-Barr virus (EBV) plays a role.

An estimated 95% of adults have been infected by this virus in the herpes family at some point, and while most infections are asymptomatic, some people develop mononucleosis (the “kissing disease”). In either case, once you’re infected, the virus remains in your cells for the rest of your life.

“In practical terms, if you’re not infected with EBV, your risk of MS is virtually zero.”

Alberto Ascherio

While not everyone who has been infected by the EBV develops MS, a 2022 study of more than 10 million young adults found that those who’d had an EBV infection were subsequently 32 times more likely to develop MS than those who hadn’t.

“In practical terms, if you’re not infected with EBV, your risk of MS is virtually zero,” senior author Alberto Ascherio, a professor of epidemiology and nutrition at Harvard, told the New York Times. “After infection, your risk jumps by over 30-fold.”

If there was a way of preventing EBV infections, then, we may be able to prevent the majority of MS cases, too, and in 2022, two teams — one from Moderna and one at the National Institute of Allergy and Infectious Diseases (NAIAD)— launched clinical trials of promising EBV vaccines.

Herpesviruses are notoriously difficult to vaccinate against, but if either of these shots — or any of the others in earlier stages of development — are effective, they could slash the number of new MS cases.

The bottom line

Our ability to treat people with MS has advanced considerably over the past few decades — there are now dozens of FDA-approved treatments to help people with the disease control their symptoms — but that doesn’t diminish the need for a cure for MS.

It’s possible we might already have one and not even know it, too.

In 2021, UK researchers launched the multi-arm Octopus trial to test whether several existing drugs approved to treat other illnesses can slow or reverse the progression of MS. Any drugs showing promise will be administered to more participants, while those that don’t seem to help will be removed from the trial.

Because these drugs are already proven to be safe, getting effective ones approved for MS shouldn’t take nearly as long as developing a brand-new drug.

“This is a major moment in MS research,” trial leader Jeremy Chataway told BBC News. “Octopus has the potential to change the clinical trials landscape around the world, and we won’t stop until we have the treatments that transform the lives of everyone with MS.”

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