Multiple sclerosis
(MS) is considered an autoimmune disease because it is known to be T-cell mediated—a
t least in part (B cells may also contribute to the pathogenesis). The myelin
antigen is the target of T cells. Myelin is not recognized as self by the
body’s immune system because it is part of the central nervous system (CNS) which
possesses its own glia that act as immune cells. From PSIO 201 we learned the
blood brain barrier (BBB) separates the central nervous system from the rest of
the body and is the interface between blood and cerebrospinal fluid (CSF). The
purpose of the BBB is to protect the brain and spinal cord from pathogens while
still allowing nutrients and molecules such as oxygen to pass freely. When the BBB is compromised, the CNS becomes
exposed to the immune system for the first time and might be misjudged as
foreign. Myelin is a shield that protects and insulates axons to permit nerve
signals to be conducted to their destination properly. When myelin is damaged,
the signal cannot reach its target. Because the location of nerve and myelin
damage varies, so do the symptoms of MS.
The trigger of MS
is not known. Genetic and environmental factors have been implicated. MS in
itself is not a fatal disease, though those who have been diagnosed may
experience challenges and loss of control of body parts. Below is a video from
the European Multiple Sclerosis Platform. I think it is very well done and the
interviews from the people with MS are enlightening:
One thing I noticed from these people is
they experienced something such as blindness or sensations of pain that motivated
them to get to a doctor to discover their diagnosis. One of the men attributed his
symptoms to stress. I appreciate the hope and awareness that these people
express for medical advances to help people who share their condition.
Something
interesting is a map of the prevalence of MS worldwide. The link below is not
up to date but the map it shows is sufficient.
It seems MS is localized to more developed
or richer countries. I wonder if it could be related to the “Hygiene Hypothesis”
expressed earlier this semester with Inflammatory Bowel Diseases, or if it
could be connected to some other factor. There is no scientific evidence I know
of that supports this idea, but I contemplate whether culture may play a role.
Poorer countries are more likely to eat things such as spinal cords and brains
of an animal because it is meat and fat and shouldn’t be wasted. Exposure to
these CNS antigens may give T regulatory cells an opportunity to calm down T
helper 1 cells and let them know the antigen is foreign, but not dangerous. I
am not suggesting we should all eat brains, but I thought it was a point of
interest that was worth mentioning.
Sources:
Hi Marissa, great discussion. I like the theory you have about eating spinal cords and brains of animals, but there's one thing that concerns me-- wouldn't eating brain antigens be similar to the sequestered antigen theory? The antigen in this case is the brain/spinal cord, and you're exposing your immune system to it, which increases the risk of it recognizing similar antigen, like your own brain and spinal cord antigen. It would seem that consuming brain and spinal cord antigens would be inherently similar to the pig factory workers presenting symptoms of MS, due to them inhaling pig brain particles and having their immune system recognizing them, resulting in "peeking" up into the blood brain barrier.
ReplyDeleteI think both you, John, and Marissa have a point. We've seen antigen exposure via an atypical route of administration help autoimmune issues with allergy shots for type I immunopathologies. On the other hand, Dr. Cohen told us about an example where slaughterhouse workers exposed to brain matter developed some symptoms quite similar it MS. I've added a link to the story below. Its worth noting a scientist working on the case suspected B cell involvement so it was likely a type 2 or 3 issue. I think we'd need to do more research to elucidate the role brain or spinal cord consumption may play in preventing MS.
DeleteThank you for those thoughts, Nick. I agree, there is still information needed to connect MS to the different types of immunopathologies. Like other inflammatory diseases it may have components of more than one type.
DeleteHello John,
ReplyDeleteThank you for bringing that concern up. I had considered the similarity of eating brain to the incident of the factory workers inhaling pig brain antigen and having an unfortunate cross-reaction in their own brains. This is speculation, but the point of entry might also be important. I don't know that eating brain versus breathing it in would have different effects on the immune system, but it might. I would be interested in a longitudinal study following the dietary habits of people and their risk of MS. Until then, I'll shrug my shoulders.
Great post, Marissa! MS is of particular interest to me because I have two members of my family who have the disease. My grandma, who was diagnosed in her 60s, and my cousin who was diagnosed in her 30s. It's a little odd to see two members of the same family with MS, as it does not appear to have any genetic links. From what I've read, it seems one of the leading hypotheses for a cause is something environmental. This is supported by what you mentioned about the prevalence of the disease being clustered in wealthier countries.
ReplyDeleteThe scary thing about MS is the many different way it can present itself, and with that the length of time that can go by without diagnosis. I believe my grandma first experienced tingling and weakness in her legs, while my cousin experienced a blind spot and some blurriness in her vision. It seems to be different for every person, as does the progression of the disease. My cousin's symptoms have pretty much subsided, as she was diagnosed early and began a very effective treatment regimen, and my grandma is one of the lucky ones who is now 90 and just recently became wheel-chair bound.
Hello Mandy,
DeleteThanks for the response! It is amazing that the range of symptoms people with MS experience is so broad. Thank you for sharing this information about your grandma and cousin. A genetic component has been implicated, specifically with HLA-D genes which correspond with MHC-II. The review in class last week stated that 60% of Europeans with MS had a specific haplotype. This gives us some information, but not enough to link the disease to a specific gene. Your grandma is very fortunate to be alive so long. I can tell your family is supportive and I am touched by how positive people with these diseases are when talking about their outlook on life.
Awesome post! I was really intrigued also by the aspect of the film where all of the MS patients discussed how they were diagnosed. I think what was really interesting is the sensation of pain that they felt that initially brought them to the doctor. One of the men even stated that the blindness he suffered didn't make him go to the doctor. So this got me thinking, how many people do see these similar symptoms, but ignore them? It would be interesting to know the statistics of people who immediately went and ended up being diagnosed, and those who waited and then were eventually diagnosed for different reasons. Thanks for sharing!
ReplyDeleteHello Bonnie,
DeleteI was surprised also by how the man did not go to the doctor after realizing one eye was blind. There are obstacles that prevent people from going to the doctor, such as fear or money or lack of time. Other reasons might include but are not limited to pride or just not caring. Because MS is a disease that is diagnosed relatively in the young (age 20-40 years) on average, I feel people of any age need to take the initiative to better inform themselves to know when their body is changing and get the help they need. This could improve chances for recovery in the future.
Hey Marissa! Great post, I appreciated your in depth discussion about MS along with the videos and map. It is nice to be able to watch a video to associate actual patients and symptoms to our discussions in class. I found it particularly interesting when you pointed out a higher prevalence of MS in developed nations compared to other countries. I also noticed when looking at the map that a considerable portion of countries around the world have no data for MS prevalence. I am curious if this could be because of patients ignoring symptoms due to the the lack of health care access, or because of different cultural approaches to health care and healing around the world. The symptoms of MS can initially be vague and may not be serious, which may prevent patients in developing countries from visiting a doctor.
ReplyDeleteHello Maddie,
DeleteThank you for pointing out the lack of data on MS in a good portion of the world. I do agree that this may be due to lack of access to healthcare or maybe even to technology in general. I had not considered though that it could be due to different approaches to healthcare. That is very likely also. I hope the increase in awareness can also increase the information we have on MS worldwide and working toward a cure.
Hi Marissa, I loved your article. It was informative and very interesting to read. The one thing that grabbed my attention in particular was your last theory in regards to brain and spinal cord consumption. It makes a lot of sense to me in how there can be a correlation between cns consumption and multiple sclerosis. And I'd say that I'd very much like to see experimentations done in order to further support this theory but the idea of eating brains and spinal cords does turn me off a little, hahaha. Either way, it would be interesting to see if that kind of experimentation does take place. With animal brains and spinal cords, I mean..
ReplyDeleteHi Sydney, yes maybe a longitudinal study could be explored. Like I've mentioned before, I am interested in diet and how it affects overall health.
DeleteHello Marissa, I found particularly moving how tha lady in the video mentioned she is loosing faith in medical advancements. Though medicine has advanced in an almost exponential rate in the past few centuries, I do understand how she would be discouraged by the lack of immediate results. Fortunately, (or perhaps unfortunately) like mentioned in the video as well, more patients are being diagnosed, hopefully this will shine more light on the disease. As to your brain consumption theory, I think it is clever and very reasonable, I wish more countries had the necessary data so we could somehow make a connection based on cultural diets or something similar.
ReplyDeleteHi Mario,
DeleteI noticed the woman's discouragement in respect to advancements in medicine as well. Like you mentioned, more cases are being diagnosed and the increase in information should ultimately lead to better therapies and (fingers crossed) a cure.
The video representation you had in this post was great. One aspect of the video that I really enjoyed was that MS patients were all really positive and that in itself could help a person that maybe just recently got diagnosed with MS see some light.
ReplyDeleteWhen I first read the post I though wait a minute where is she going with this whole third world country eating brains and spinal cords thing, but when I continued reading I really liked how you've linked other ideas from other concepts such as the "hygiene hypothesis" into your blog for MS. The idea of other countries eating all these fats that we don't eat never correlated into my mind with MS but I really liked your hypothesis and information you had to back it up. Ideas like these are how we find cures!
Thanks Anaiz. It has been really fun learning a little about these diseases these last two weeks as an "expert". I feel I have learned quite a bit, but there are still gaps. I hope that people can keep sharing ideas without being afraid to be wrong, because finding out something is wrong is still an achievement and adds to public knowledge.
DeleteThanks for the great post Marissa! I really like seeing the videos of people afflicted with he disease. I think it means a lot to hear what these people have to say because they are dealing with it first hand. I was really surprised that the man who had blindness in one eye didn't immediately go to the doctor, he even said he knew it was serious. One of the things i always notice and find very inspirational about videos like this is how people who have a serious disease like this dont let it define them. They talked at the end about how they still go on and live the best that they can.
ReplyDeleteI really appreciate your comment, Dan. Especially as future professionals, we need to be sensitive to these individuals and remember their desires. They do not want to be defined by their disease. The ultimate hope is that they will overcome the disease and continue to live as individuals.
DeleteMarissa,
ReplyDeleteI really liked your post! I took a class last semester on the cellular physiology of neurons (NROS 307) and was able to relate some of that knowledge to this post. Myelin is a membranous material and is designed to resist the flow of charge across the neural axon. It is thought to work somewhat like an electrical circuit in a series. I checked out the link you posted through the National Institute of Neurological Disorders and Stroke and found it interesting that the formation of plaques is what leads to the inflammation. The methods that lead to the formation of these plaques may be a good prospect for study.
Thank you, Michael.
DeleteI agree, the formation of plaques or scar tissue in myelin in MS would be a good place to study because if we could reduce that process then there would hopefully be less damage and consequences.
Good job Marissa! The video was illuminating in a way that a description of symptoms may not have been. I think the older of the Spanish women may have been slurring her speech, but I can not tell with her accent. I recall from the review article about which I was responsible facilitating a discussion, numerical trends do exist that link infant mortality inversely proportional to allergy, MS, and IBD.
ReplyDeleteThank you Abraham for bringing that to my attention. I had not thought to look back at the IBD reviews. I found the reference which is an article from the journal Neurology from 2006 called "Multiple sclerosis and the hygiene hypothesis". The article observes an inverse relationship between the prevalence of a helminth (T trichiura) and the prevalence of MS. It is interesting. The article can be accessed through the university library website. The authors were Fleming and Cook in case anyone else would like to look it up.
DeleteI think that one of the most difficult things about MS is that it's symptoms dependent on location and severity of the myelin damage. It seems like this would be a hard thing to target in terms of treating someone who has already experienced damage. Preventing MS altogether seems like a better way to go about it than to look at treating damaged neurons. I enjoyed that you talked about how culture and food could actually be a risk factor. The neuronal tissue that is consumed in other cultures could introduce that to their immune system so that their own immune system does not avidly attack their own nervous system when the BBB is breached.
ReplyDeleteHi Marissa,
ReplyDeleteSuch a powerful video you included, and I'm glad you did. It is crucial for people experiencing these symptoms to head into the doctor as a precaution. My neighbor had been experiencing random blindness when I was in high school and she went in for a check up and was determined to have MS. The map you included was very interesting, and I'm glad you brought to light the hygiene hypothesis. Unfortunately our intense cleanliness has lead to unintended consequences on the population.