Januari 02, 2017
- [voiceover] we're goingto refer to ankylosing spondylitis as as. so you don't have to keephearing me say this long thing. but if we go word by word just once, you'll see that ankylosing means fusion. so it describes the spinebeing fused together. spondy, this first part ofthe word, refers to the spine. and then -itis anywhere is inflammation. so this is an inflammation of the spine
and at the sacroiliac joint, actually, and it leads to the fusion of the area. there's some buzz words surrounding it. so one of them would bethat it is the poster child for a group of different diseases that are referred to collectively as the seronegative spondyloarthropathies. spondylo-, so again, that's the spine, and then arthro, whichrefers to joints in general,
and then pathologies or illnesses. so what this means is that they are rheumatoid factor negative. they do not have rheumatoid factor. but they also can appearlike rheumatic joint diseases because it's systemic and itinvolves the immune system. so speaking of the immune system, the other buzz word you need to know is hla-b17.
i'm sorry, i always say that. it's b27. again, it's part of the immune system. it's an antigen on the surface of the cell that can be recognized by t-cells, which can recruit things to attack it. so this is the autoimmunecomponent of the disease. this hla-b27 associationactually exists for the seronegativespondyloarthropathies in general, but here, in particular, for as you should
remember that connection. and then, just a littlebackground information on the group of peoplethat tend to get this. remember, nothing is absolute, but if we're looking for patterns, it's going to be malesand relatively young ones, actually, really young ones, from 15 to 45 is going to be the meanor the biggest group of people who get as or that'swhen it's diagnosed the most.
so the name kind of tells us what symptoms are characteristic. we have this fusion of the spine. i drew it kind of like here, because it can be inthe middle of the back, more commonly in the middleto lower back of the spine. so look at the curvature of this, this natural curvature of the spine. so this is a person lookingto the right at the screen.
the head is over here. as you come down the back,it kind of curves in here, and the pelvis is down here. this whole thing issupposed to allow you to bend forward, bend backwards. if you look at the areahere, you should be able to actually bend forward morethan you can bend backwards. but the important part is thatwith ankylosing spondylitis you don't have that kind of free movement
because you have fusion, and this is why one of the nicknames for thesymptom is a bamboo spine. like a piece of bamboo, instead of a bendable stack of bones. bamboo spine. so while bamboo spine iswhat we think of immediately when we see as, remember that it's a systemic autoimmune disease, which means it affects, itcould potentially affect
everywhere in the body. and this person might have fever, malaise, other nonjoint problems. when we're talking aboutjoints, aside from the spine, it also tends to affectthe iliosacral spine. iliosacral. i haven't drawn thepelvic bowl of bones here, but this is the joint that,think of it how your leg, your thigh attaches to your body.
so the pain and inflammationcan actually go down, following the spine, andcan shoot into the legs, and the iliosacral jointitself can be affected as well. so the pain, i think of itas this area for joint pain. if we want to talk about systemic effects, it has a pattern ofaffecting two other places. one is eyes, particularly uveitis, and the other one is the aorta.
so the aorta is thebig pipe, the big hoop. this is just the fourchambers of the heart, and this is the leftatrium, the left ventricle. this is not anatomic,because technically the aorta comes kind of above theheart, comes out this way, but just drawing our little cartoon here, just to show you the aorta is this pipe that comes off of the left ventricle, and it pumps blood to the whole body.
this is where oxygenated blood, where we think of redblood with oxygen in it, reaches the rest of the body. so if we have inflammationin the aorta here, you'll see at least twocardiovascular problems. first in the eyes we have uveitis. you can have redness, inflammation. this uveitis is kind of nearthe front chamber of the eyes. it can lead to redness, pain, discomfort.
they can be afraid of light. they can see things floatingin front of their vision that's not really thereor not physically there. so that's uveitis, and it has an hla-b27 association as well. and then in the aorta, like i said, this is where all theblood goes to the body. so if we have inflammation, inflammation in thewalls of the aorta here,
we can get what's called an aneurysm. an aneurysm is kind of likeif you have a pipe here and you have some slack in the walls or some weakening in thewalls, kind of bulges out here and becomes a weak point in the pipe. this can happen in our bloodvessels all over the body, but if it happens here,this where the heart and the aorta are connectedis the aortic valve. very important valvethat prevents the blood
from flowing this way, thebackflow into the heart. so if you have uveitis,you might have a stretching or an aneurysm near theopening here, near the valve. this part is just slack, andthe valve can't close properly. and then what you get is some backflow into the chamber of the heart. and we use green to show backflow. so red, forward flow. green is back. so not only is the bodynot getting enough blood,
but the heart has to pump extra volume because each time what'spumped out comes back in. so this can lead to aserious problem in the heart, and we call it aortic regurgitation, meaning from the aorticvalve there's backflow. regurgitation. this is a side effect of the aortitis, but it's also it's own disease. oh, i forgot to writeout aortitis, aortitis.
if you realize the pattern here, -itis. itis in spondylitis, everything-itis means inflammation. unfortunately, as is verydifficult to diagnose. dx for diagnosis. because the symptoms,even though it looks like i've demonstrated a pattern here, it really can occur anywhere. it can just look like plainold osteoarthritis for years. so it's a tricky thing to diagnose,
and there's different ways togo about it, different levels. so we can start with an x-ray. the bamboo spine, if it'salready fused, we can see it. there might be blood tests,because the blood will show us, there's no as bloodtest, but it will show us how much inflammation is there. for example, the erythrocyteor red blood cell sedimentation rate. this is a marker for inflammation.
so is the c-reactive protein. so these are also nonspecific to as, it could be any autoimmune disease, but at least it will helpus know we're dealing with an autoimmune disease andnot just wear and tear. there's also genetic, becausethis disease seems to have a pretty genetic pattern. also, the coding for hla-b27,the coding for the antigen, we can trace that as well.
and then there's somethingi guess we don't really use to diagnose as, but we do use it to track how it's progressing,how fast and how bad, and it's called the bath, which is the place in englandwhere it's discovered, ankylosing spondylitis disease activity index. what a mouthful. everything is an acronym. but this index allows us to again track
how this patient is doing over time, how they're doing with their treatment. and speaking of treatment, managing as can seem, canlook actually a lot like managing rheumatoid arthritisor the autoimmune diseases because the principle is the same. you need to reduce inflammation. there's a class of different drugs that with different mechanisms
but they're grouped togetheras disease-modifying anti-rheumatic drugs, because it used to be developed for rheumatoid arthritis. so what's special aboutthem is even though they go about it in different directions, it actually slows theprogression of the disease, not just treat the symptoms. and we're going to usethis for as as well.
there's tumor necrosis factor, which is something that causesinflammation in the body. it's basically somethingthat can program a cell to kill itself, which canbe helpful in preventing cancer within our body, but here it's just acts to the inflammation. so tnf inhibitors can be used, again to reduce the inflammationgoing around in the body. we can use nsaids.
these are the over-counter, you think of probably as pain meds, for example, your ibuprofen. and they not only treat the pain, because the fused spine and everything can be really painful, theycan also reduce inflammation. and then stronger pain meds as well, depending on the level of discomfort. so, as you see, the theme hereis to decrease inflammation.
that's the most basic ankylosingspondylitis in a nutshell. remember that it can be similarto rheumatoid arthritis, in terms of affecting the whole body and a lot of inflammation. but the fact that it fusesand affects the spine, the eyes, the heart, and thefact that it does not have rheumatoid factor makes it different.
Tidak ada komentar
Posting Komentar