hey everyone in this lesson we're going to discuss what you need to know about ankylosing spondylitis including risk factors pathogenesis signs and symptoms and how we diagnose in how we treat ankylosing spondylitis so what is ankylosing spondylitis if we were to look at the words in more detail ankylosing refers to stiffening or fusion that's what ankylosing means and if we were to break the word spondylitis down the prefix spawned aligned and itis means inflammation so ankylosing spondylitis is essentially a fusion of the spine due to inflammation but more specifically inclusing spondylitis is a chronic seronegative inflammatory spondyloarthropathies so a lot of words there so it's chronic because it's long lasting condition it's seronegative because if we look at bloodwork rheumatoid factor is negative in its inflammatory because this is a inflammatory condition involving inflammation of the joints and spondyloarthropathies again spawned old means spine arthropathy means disease of the joint so that's what all that means an enclosing spondylitis is a type of axial spondyloarthritis now interestingly enclosing spondylitis is more common in men compared to women the ratio of men to women is actually three to one so this is a more common condition in males and it has an onset in early adulthood typically by the age of late teens to early 20s it can be anywhere from 15 to 45 what's he didn't know about ankylosing spondylitis is that the majority of cases of ankylosing spondylitis are HLA b27 positive so if we look at a patient with ankylosing spondylitis and we check their HLA b27 status they're more likely to be positive and this can be anywhere from 80s to 90 percent of cases have this positive blood finding and this all ties in with family history as well since this is a family trait so the epidemiology of ankylosing spondylitis can be remembered by what we call the rule of two's 0.2 percent of the general population has an spondylitis so it's a rare condition 2% of HLA b27 positive individuals will have ankylosing spondylitis so in the general population depending on ethnicity there's probably about 8 to 10% of the general population is HLA b27 positive only 2% of those individuals will have ankylosing spondylitis so having HLA b27 positive doesn't necessarily mean that you are going to get ankylosing spondylitis but majority of ankylosing spondylitis patients are HLA b27 positive and the other part of the rule of two's is that 20% of HLA b27 positive individuals with an effective family member will have ankylosing spondylitis themselves so it seems to be related to HLA b27 but also having a family history all of this seems to tie together with your increased risk of getting this condition so what does the pathogenesis of ankylosing spondylitis so as we mentioned before there's genetic causes but there's also non genetic risk factors as well and this all ties together with gut microbiome alterations very interesting so when these two combine together they lead to the activation of lymphoid cells and these lymphoid cells can migrate to the axial skeleton and sometimes into peripheral joints as well so these are innate lymphoid cells that produce interleukin 17 and interleukin 22 so these are cytokines that can lead to a variety of effects causing inflammation in the joints the interleukins along with tumor necrosis factor alpha or TNF alpha are connected and they can lead to inflammation in the joint as well there's also some interaction with cyclooxygenase enzyme or Cox enzyme and what's important with all of this inflammatory response is mechanical stress so mechanical stress on the joints particularly in the spine and some peripheral joints can lead to inflammation in those joints anyway and with all of this pro-inflammatory response due to these migrated lymphoid cells it gets worse and we get this pathological response being heightened and causing damage so you might be wondering where does HLA b27 play a role in all of this well HLA b27 are human leukocyte antigen b27 plays a role in this pathogenic process through its effects on altering the gut microbiome so this is where it seems that HLA b27 is involved it leads to alterations in gut microbiome that are necessary for the genetic and non-genetic risk factors to all come together and activate these lymphoid cells so with all of that inflammation in the spine and other joints we go from having healthy vertebrae to inflamed to vertebra and eventually if the inflammation is not dealt with appropriately we start to see progressive fusion of owns and we start to see loss of the cartilage in between the vertebrae what are some of the clinical features of ankylosing spondylitis so the axial skeleton involving the spine is the most commonly affected particularly the most prominent symptom patients will have is going to be mid low back pain and the mid low back pain is not like a lot of mechanical or back pain that many patients will present with it is inflammatory in nature what does that mean well they're more likely to have prolonged morning stiffness so in the morning when they first wake up and they try to get going the backs extremely stiff and this prolonged morning stiffness is greater than one our mechanical lower back pain might have morning stiffness but it's usually less than 30 minutes so if it's prolonged morning stiffness of greater than one hour it's more likely to be inflammatory in nature another key component of an inflammatory lower back pain is pain at night so if pain gets worse and worse at night it could be indicating that this pain is inflammatory and what's also important to note about this mid lower back pain in ankylosing spondylitis in limit or pain in general is that it gets better with activity so at first when you first start getting started there's a lot of stiffness there can be gelling so stiffness when you rest for a while and then while you get moving that pain and that stiffness gets better and that's actually a key component of inflammatory pain whereas non inflammatory pain like other types of arthritis like osteoarthritis usually gets worse with activity so this is a key defining or distinguishing feature of this type of pain we may also see sacroiliitis so pain of the sacroiliac joint or inflammation of the sacroiliac joint this presents as a talk of pain so pain in the bum and that pain can alternate it can go from one side to the other or can be present in both sides we can also see neck pain so this affects the entire spine including the neck and actually the neck pain can be one of the first presenting features of this condition and because of that prolonged inflammation in the fusion of the bones patients with this condition can begin to see decreased spinal mobility they have a difficult time bending and flexing their spine now although the axial spine is the most commonly affected the lower extremities can also be affected with regards to the peripheral arthritis we talked about earlier so the most common joints that are affected besides the spine and the vertebrae are ankles hips and knee so with this condition we can see arthritis of the ankles hips and knees as well we can see enthis itís so emphasizes is an inflammation of where the tendon inserts into the bone and typically with 3 yards to this finding we see heel pain so pain of the Achilles tendon word inserts into the calcaneus and we can also see dactyl itís so inflammation of the toes can be found as well so because of all these features we can have certain complications and some of these include kyphosis so what is kyphosis so in a normal spine we have normal curvature of the spine there is cervical lordosis thoracic kyphosis in lumbar lordosis but with regards to kyphosis we get an increased curvature of the thoracic spine so there's an increased thoracic kyphosis which can cause a lot of issues with the posturing of an individual so the posture can be affected if we were to do an occipital wall test so we basically get them to push all the way against the wall there's a huge distance between their occiput in the wall whereas in a normal individual it should align with the back so we wouldn't have that huge distance other complications include spinal stenosis so because of all of that inflammation in that fusion of bone the vertebrae in the spine can become fused and enlarged and have syndesmosis form which can impinge on the spine itself leading to spinal stenosis in another complication is secondary osteoporosis because of all that inflammation and some of that remodeling we talked about we can lose some of our bone density so the bones can be more parodic or have osteoporosis so if we look at a normal bone here compared osteo process we can see the pores are enlarged in osteoporosis what are some other findings so these are more due to the inflammatory nature of the ankylosing spondylitis there are extra articular manifestations with this condition one of them is acute anterior uveitis so the lluvia is actually one of the layers in the eye and this becomes inflamed with this condition another eye finding is sclerosis so it's not like uveitis where we have inflammation even over the pupil and the iris we only see it on the sclera of the eye but you can see very red and in your feminist areas that is sclera TISS so information of the sclera of the eyes we can also see a or decree Gurjit ation which can be a relatively severe manifestation of this condition because it can lead to structural heart change if not dealt with appropriately we can also see apical interstitial lung disease and another severe manifestation we can also see i GA or immunoglobulin a nephropathy with this condition so that kidneys can be affected and we can see inflammatory bowel disease with this condition as well and we can see dermatological findings like psoriasis as well so ankylosing spondylitis not only affects the spine and peripheral joints but it can affect many other parts of the body as well due to its systemic inflammatory actions these parts of the body can include the eyes the aorta of the heart the lungs the kidneys the gastrointestinal system and even the skin as well in the form of psoriasis there are important radiological features in ankylosing spondylitis so if we were to take a look in an x-ray and we look at the SI joint or the sacroiliac joint we can see something termed pseudo widening pseudo widening of the sacroiliac joint here if we do an x-ray of the spine we can see what we call squaring of edges or the shiny corner sign so if you look here these corners are these edges of the vertebra are somewhat shiny so you can see here where there's inflammation involved and as this condition progresses the bones can fuse and the spine can become something we know as bamboo spine so here's an x-ray image of a typical bamboo spine so when you look here there's no separation of the vertebra they're all fused when we see bamboo spine this is a very key finding with ankylosing spondylitis so if you ever hear bamboo spine it is ankylosing spondylitis how do we diagnose it so diagnosis of ankylosing spondylitis is generally through clinical special tests to check for sacroiliitis one of the tests is the faber tests or patrick's test and that test is positive so what an examiner does is that they flex the hip in the knee they a be duct the leg and then they externally rotate as you can see in this image here if we get pain in the area of the sacroiliac joint that is a positive test there's also something we called the modified show Bursa test which is also positive in ankylosing spondylitis this indicates decreased spinal range-of-motion so generally what we do is that we make a mark at the dimples of Venus and we make a mark about 10 centimeters above the dimples and then we get the patient to flex so we get them to bend over to try to touch their toes and then we measure out again and that new measurement should be greater than 15 centimeters so when we line up from the dimples to that 10 centimeter mark it should actually be greater than 15 centimeters or at least 15 centimeters if it's not that is a positive test indicating a possible ankylosing spondylitis so I know that's difficult to understand by just hearing it so please look it up on other videos to see what it looks like so those are two clinical tests indicating sacroiliitis with Faber's tests and decreased spinal range of motion with the show burst test indicating or increasing our suspicion of ankylosing spondylitis so those can help with the diagnosis of ankylosing spondylitis but another way to make the diagnosis is by looking at how long they've had the back pain and when it started so if they had lower inflammatory back pain that's been going on for greater than 3 months and that back pain started when they were less than 45 years of age that is more likely to be ankylosing spondylitis again lower inflammatory back pain so inflammatory back pain so pain with prolonged morning stiffness worse at night and gets better with activity that doesn't completely give us the diagnosis however we still need to do some other testing we can look at their HLA b27 status if they're positive that is it also another point toward making the diagnosis and we have to look at x-ray findings so if they have radiological findings that we talked about in the last slide they do have classic ankylosing spondylitis and without radiological findings that is non radiographic axial spondyloarthritis so with radiological findings that's a class ankylosing spondylitis without radiological findings that's non radiographic axial spondyloarthritis so two different things but if they have no radiological findings but they have at least four of the symptoms or clinical findings we talked about in the last couple of slides then not the radiological findings but the other findings like the inflammatory back pain the emphasizes acute anterior uveitis or the sclera itis or the psoriasis those types of symptoms or clinical findings if they have at least four of those then that is ankylosing spondylitis as well so again we want to look at how long they've had inflammatory back pain has to be at least three months with an onset less than 45 years of age HLA b27 positive if they have radiological findings that's classic and closing spondylitis without radiologic findings we have to do a bit more work it's non radiographic axial spinal arthritis if we have at least four symptoms or for clinical finds we talked about before that's an ankylosing spondylitis again again it's not clear-cut because some individuals with ankylosing spondylitis don't have HLA b27 positive so it's a mix of all of these things that help us make the diagnosis how do we treat it so treatment of ankylosing spondylitis is started off with conservative measures so the goal is to prevent or slow to the progression of the spinal fusion so one of those ways is through physiotherapy so physiotherapy can help reduce some of that mechanical stresses sounds counterintuitive but physiotherapy can help build some of those paraspinal muscles and other muscles to help support the spine exercise particularly swimming can also help with this as well breathing exercises can also help and quitting smoking can also help reduce some of the inflammatory process of this condition as well with regards to pharmacological treatments non-steroidal anti-inflammatory drugs or NSAIDs are the first-line therapy so you can think of things like naproxen or celecoxib and for a lot of patients all they need is a high dose of NCA's to help them with their ankylosing spondylitis symptoms but with prolonged high dose NSAIDs we want to make sure that they're protected in other ways due to the side effects of NSAIDs so we want to make sure they're on a proton pump inhibitor for gastrointestinal issues due to the NSAIDs we also want to keep an eye on their blood pressure and their kidney function for other patients that have other issues like peripheral arthritis we can use disease modifying agents so Demers like methotrexate and for patients that don't respond to NSAIDs and don't really respond to other treatments we can use biologics these are very expensive some of these include TNF alpha inhibitors like o laboum AB and then another class of biologics that can be used are they jak 1 inhibitors like but to sit in him so if you wanna learn more about other rheumatological conditions please check out my Rheumatology playlist and if you haven't already please consider liking subscribing and clicking the notification will help support the channel and stay up-to-date on future lessons and as always continue to live laugh and learn and I hope to see it next time