A New Form of Treatment for Multiple Sclerosis
Published in
4 min readApr 12, 2022
Could these transplants be the future for patients who suffer from MS?
What is Multiple Sclerosis?
- Multiple Sclerosis is an auto-immune disorder, one where the immune system of the patient attacks its own cells and systems.
- This happens when the immune system mistakes these systems as foreign and attacks them.
- In the case of Multiple Sclerosis (MS), it attacks the myelin sheath in the brain and spinal cord.
- The myelin sheath is a substance which forms a protective layer that wraps around the axons of neurons found within the central nervous system (CNS) and the peripheral nervous system (PNS).
- It has roles in insulating and protecting the neurons, and in increasing the number of electrical signals being transferred.
- In the case of patients with MS, the immune system’s attacks on the myelin sheath cause the it to become inflamed in small patches (plaques or lesions).
- These patches of inflammation can disrupt the messages travelling along the nerves and result in some of the symptoms seen in MS, e.g.: fatigue; vision problems; numbness and tingling; muscle spasms, stiffness and weakness; mobility problems; pain; problems with thinking; learning and planning; depression and anxiety; sexual problems; bladder problems; bowel problems; as well as speech and swallowing difficulties.
A New Treatment?
- An early stage trial has shown that transplants of immune cells that target the Epstein-Barr virus have shown promise for treating multiple sclerosis.
- In an initial trial, US firm Atara Biotherapeutics gave 24 people with progressive MS injections of T-cells that seek out and destroy cells infected with the Epstein-Barr virus, the cause of glandular fever.
- The cells are extracted from donors who had previously had an infection of Epstein-Barr virus, and are immunologically matched to avoid rejection.
- The firm said that 20 of the people who received the injections saw their condition either stabilise or improve.
- It must be noted that, while the phase I trial didn’t include a control group to rule out the placebo effect, MRI brain scans using a technique called Magnetisation Transfer Ratio (MTR) suggest that there was remyelination of nerve cells — the myelin around them regrew to some extent.
- Normally, MTR measures decline in those with progressive MS, but MTR measures increased in those whose symptoms stabilised or improved.
- The company is now enrolling another 80 people in a phase II trial.
The basis behind the treatment
- Recent studies have greatly strengthened the case that the Epstein-BArr virus is a cause of MS.
- In January, a study of 10 million military personnel in the US reported that infection with the virus preceded almost every case of MS.
- Another study, also published in January, showed that one of the proteins produced by the Epstein-Barr virus is very similar to a human protein produced in the central nervous system, and that at least a fifth of people with MS have antibodies that bind to both proteins.
- In some people the immune response to this viral protein may mistakenly target this human protein as well.
- Since the virus hides away in people’s bodies after the initial infection and sometimes reactivates, this immune response can be continually stimulated.
- If this is the case, tackling the virus should help treat all forms of MS.
Whats’s next?
- The next step in the process of drug development in which a wider group receives treatment.
- Increasing the sample size and including placebo and control groups will help determine whether the potential of this new treatment can be realised.
- Clare Walton of the Multiple Sclerosis Society UK says, “We’ve seen treatments look promising at phase I or even at phase II, but then when you do the large randomised trials they don’t show any outcome.”
- It is important to prove the relationship between the treatment and outcome is causative and not correlative.
References:
- Science, DOI: 10.1126/science.abj8222
- Lanz, T.V., Brewer, R.C., Ho, P.P. et al. Clonally expanded B cells in multiple sclerosis bind EBV EBNA1 and GlialCAM. Nature 603, 321–327 (2022). https://doi.org/10.1038/s41586-022-04432-7
