Celiac disease Digonosis By Medicos

  • [Voiceover] The name celiac disease doesn’t actually tell us much about what the disease does, but there’s another namethat I think is a little bit more informative. And that’s gluten-sensitive enteropathy. Entero refers to small intestine and pathy refers to disease, so there’s a diseaseof the small intestine that’s caused by gluten. It’s also important tonote that celiac disease is an autoimmune disease, that is, the immune system isattacking the small intestine. We don’t actually knowwhy that’s happening, but we do know that somepeople have a genetic predisposition towardsdeveloping the disease. We also know that peoplewho have celiac disease are more likely to developother autoimmune diseases as well, such as type 1diabetes or thyroid disease, and we know that it’s morecommon in people who have down syndrome. Now even though we don’t exactlyknow why the immune system is attacking the small intestine, we can still kind of lookat the pathophysiology and what’s exactly going on in there. Now remember that gluten iscomposed of two different proteins. There’s gliadin and there’s glutenin. We’ll mostly focus on gliadin.
  • Now let’s say you eatsomething that contains gluten. That gluten will eventuallymake its way into the small intestine, and here Ikind of have a diagram of the different layersof the small intestine. Once it reaches thispoint, for some reason, your body will start toproduce antibodies against the gliadin. This will then recruitall sorts of lymphocytes, or white blood cells,into your small intestine. Because you have a lot oflymphocytes and antibodies in your small intestine, wesay that there is inflammation in there. So it’s almost as ifthere’s a war zone going on in your small intestine, and that war zone kind ofcauses damage to the wall of the small intestine. Now remember that the wallis responsible for absorbing food and water, so, theprocess of absorption will be disrupted. For example, you can’t reallyabsorb much water anymore. That water will justend up in your stools, in a condition simply known as diarrhea. Similarly, you can’t absorbfats very well either, and that will manifest inyour stools in a condition known as steatorrhea. And finally, you may beunable to absorb iron or vitamin B12. As a result, you may startto experience anemia. So these are some of themajor symptoms associated with problems in absorption, but there’s actually one moresymptom that’s not really associated with absorption. Let’s say that here wehave the body of someone who has celiac disease,and they’ve eaten something that contains gluten in it. All of a sudden, they maystart to see these rashes and blisters forming ontheir abdomen and their arms. These rashes and these blistersare going to be extremely itchy.
  • This is a condition knownas dermatitis herpetiformis. It’s not too common. It affects about 10% of peoplewho have celiac disease, but, it’s one of the manysymptoms that doctors may look for when diagnosing the disease. Now, speaking of diagnosis, Iwant to talk a little bit more about how some doctors candetermine if someone has celiac disease. First, what they’ll do isthey’ll determine if you have a high probability or lowprobability of developing the disease. They’ll determine this bylooking at your family history, because remember thatpeople have a genetic predisposition towards developing it. If they see a lot of familymembers having the disease, then they may orderwhat’s called a biopsy. A biopsy’s when we collecta small sample of the tissue that we’re interested in. After you collect thatsample, you then look at it under a microscope to seeif it looks healthy or not. The way we collect thistissue is through a procedure called an upper endoscopy. They basically take thiscamera that looks like a tube called an endoscope, and they put it through your mouth, down your esophagus, through your stomach, and then eventually, into your small intestine. Because it’s a camera, thedoctors can then actually see what’s going on inthe small intestine, and, they can collect that sample. Now, let’s say that you mayhave a low probability instead. If, for example, you don’thave a lot of family members who have celiac disease, or even any other autoimmune disease, you may not want to subjectthe patient to this really invasive procedure, sofirst, what we’ll do is a few blood tests. We’re mostly going to belooking for different antibodies that are characteristic of celiac disease, because remember, that thisis an autoimmune disease. So there are five classes of antibodies, called IgA, IgD, IgE, IgG, and IgM. We’re mostly going to look forantibodies that fall in the IgA category, and thereare two different types. There’s anti-tissue transglutaminase, and there’s anti-endomysial.
  • If these blood tests turn out positive, that is, you have theseantibodies in your system, then there’s a chance thatyou may have celiac disease, so then the doctor may go onto continue with a biopsy, just to confirm things. Now, let’s take a look at thatbiopsy in a little bit more detail, so here we havetwo different pictures of the small intestineunder the microscope. On the right, we have ahealthy small intestine, and on the left, we have thesmall intestine of someone who has celiac disease. First, I want to highlightwhat’s good about the healthy one. You’ll notice that it hasthese finger-like protrusions called the villi. These guys are responsible for absorption in the small intestine. There are also thesegrooves between the villi known as crypts. In the disease sample, you’llnotice that these villi are actually blunted. This is known as villous atrophy. In addition, those cryptsare actually elongated so they’re becoming a little bit bigger. And that’s because all sortsof cells are dividing there, so we call this crypt hyperplasia, so it’s kind of like themountains of the villi are getting smaller, andthe valleys of the crypts are getting deeper. Now, there’s one morecomparison picture that I want to show you as well. In this case, on the left, we have someone who is healthy, and on the right, we havesomeone who has celiac disease. Now, remember, that in celiacdisease, you have a lot of inflammation in the small intestine. That means that you have alot of lymphocytes in there. So it would be a good ideato actually look for these lymphocytes, so, you’llsee these kind of blobs that are in the villi ofthe small intestine, right? And, the celiac diseasetissue actually has a lot more of them. Now, these blobs arecorresponding to the lymphocytes, and it’s pretty clear inthis picture that there are way more lymphocytes inthe disease tissue than in the healthy. Now, these are really themain signs that we look for with regards to celiac disease, and if the tissue sample shows this, then that’s how we can diagnose it, but diagnosing it is one thing.
  • I mean, how can we really treat it? Well, unfortunately, therearen’t really many medicines or procedures availableto treat celiac disease. Once the gliadin fromthe gluten makes its way into the body, it’s prettydifficult to stop the antibodies from marking them, so, ultimately, the bestthing that anyone can do is to simply go on a gluten-free diet. Now, usually, these gluten-freediets are pretty strict. But I think that now, giventhat there’s this rise of gluten-free diets, it’sbecoming a little bit more easy for people to maintain these diets. As long as you don’t consume gluten, then you should be okay, evenif you have celiac disease.

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