What is the understanding of Multiple Sclerosis in 2021?

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Multiple Sclerosis (MS) is a potentially crippling disease which although well known within the medical and scientific fields, is still not very well understood. Within this article, I will go over the current understanding of MS, potential explanations for its more confusing components, treatment options as well as the effect of vitamin D on MS incidence. Before I continue, I would like to mention that I write about MS exacerbations and MS remissions. An MS exacerbation is a flare-up of MS symptoms, while MS remission is the opposite of this, where MS symptoms reduce for some time e.g. weeks, months or more. Remission does not lead to MS being cured, however.

Now that is covered, what is MS? MS is a disease of the brain and the spinal cord, known together as the central nervous system (CNS). MS is when the immune system attacks the myelin covering the nerve fibres in the nervous system, as a result, MS is known as an autoimmune disease. This causes issues for the electrical signals travelling across the body, resulting in paralysis of varying degrees over time, as the nerves are damaged without the myelin sheath. The symptoms of MS are mainly, numbness in limbs, tremors, co-ordination issues and vision problems, although in most MS patients at first, only one or two of these main symptoms are prominent.

How can you prevent your chances of getting MS? The main way scientists have found is to increase your vitamin D levels, which can be done by having more sunlight exposure. The reason for this is that higher vitamin D levels result in immune cells being monitored more by the body, reducing the chance for autoimmunity resulting in MS occurring.

Although it is known that in MS, T cells, after being activated in the lymph and moving to the CNS using various blood vessels, carry out the cell-mediated response and produce B-lymphocytes which form the basis of the humoral response. These B-lymphocytes then divide into plasma cells which produce antibodies with variable regions complementary to the antigens on the CNS cells. This results in the myelin sheath around the neurons being killed, and so paralysis occurs over time, symptoms which show that MS is occurring.1

This mechanism is well known in the medical field, but it still unknown what causes the T/B-cells to be activated against the CNS antigens. This is where the relatively new research comes into play. One of the most prominent theories of the day is molecular mimicry. This is where the immune system encounters a cell infected by a virus that has similar antigens to CNS myelin or mimics the patterns of brain/CNS cells, such that the immune system attacks CNS myelin, misidentifies CNS myelin cells to be virus-infected cells. This would explain why MS is not a hereditary disease and can start at any time in a person’s lifetime.

How can MS be treated? At the moment there is no cure for MS, however, promising research recently may change that soon. Part of this research centres around interferons, or beta interferon specifically. Interferons are proteins that are produced by body cells to change the immune cells’ response to contact with pathogens. Beta interferons are released towards the end of immune responses, reducing inflammation, reducing MS exacerbation numbers as well slowing the rate of progression of the disease. This is what beta interferon drugs are trying to recreate, and if successful, could perhaps make MS a disease of the past in a few decades.

Another area of research for curing MS, which is less advanced so far, is the link between MS and gut bacteria. Certain gut bacteria along with B-lymphocytes have been recorded to travel towards the brain from the gut, during MS exacerbations, leading to the belief, that these B-lymphocytes reduce inflammation and protect the brain. If what activates these B-lymphocytes to move across the blood-brain barrier towards brain lesions caused by MS, this can lead to new treatments for MS.2

Therefore, MS, although it has many confusing areas to its mechanism, has possible explanations coming up within the medical field now. Furthermore, it has now been shown that higher vitamin D levels result in a lower chance of developing MS, gut immune cells’ role in reducing MS, and the potential treatment options now and in the future. In conclusion, although MS is a disabling disease in many cases, with more knowledge about its mechanism, the incidence and crippling effects of MS can be reduced greatly in the future.


References

  1. Mayo Clinic. n.d. Multiple sclerosis – Symptoms and causes. [online] Available at: <https://www.mayoclinic.org/diseases-conditions/multiple-sclerosis/symptoms-causes/syc-20350269> [Accessed 27 March 2021].
  2. Ellis, M., 2021. Multiple sclerosis: What is its link with the immune system?. [online] Medicalnewstoday.com. Available at: <https://www.medicalnewstoday.com/articles/multiple-sclerosis-and-the-immune-system-what-do-we-know> [Accessed 27 March 2021].

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