In China’s long history of 5,000 years, there was a long time when people could not stand up straight as human beings, and that was because of the feudal rule. However, today, as China becomes stronger, there are still so many people who cannot “straighten their backs” and live a painful life with a stooped back, why is that? Because of the pain of the disease – ankylosing spondylitis. What kind of disease is ankylosing spondylitis? Why does it make people unable to hold up their backs and have to live hunched over? Ankylosing spondylitis (AS) is a chronic progressive systemic inflammatory disease that affects mainly the medial joints, such as the sacroiliac joints, hip joints and spine. The common symptom is stiffness or pain in the low back, which may be relieved by activity. Ankylos spondylos describes the advanced stage of AS. I. Relationship between AS and HLA-B27 I am often asked by patients whether HLA-B27 positive is AS or HLA-B27 negative is not AS, what exactly is the relationship between the two? The prevalence of AS has been reported differently from place to place, mainly because of the positive rate in the population; the prevalence rate of HLA-B27-positive Indians in the United States and coastal Indians in Canada is as high as 50%, while the prevalence rate of HLA-B27-negative blacks in the southern hemisphere, who are not of mixed race, is extremely rare. The prevalence of AS in China is 0.3%, the HLA-B27 positive rate in the general population is 6%-8%, while the positive rate in AS patients is 90%. the onset of AS is closely related to HLA-B27, and has a family tendency to develop. It has also been shown that HLA-B27-positive patients or those with a family history of AS have a significantly higher likelihood and risk of developing AS. Conversely, approximately 80% of HLA-B27-positive patients do not develop AS, while 10% of AS patients are HLA-B27-negative. This shows that AS is closely related to HLA-B27, but not necessarily AS if HLA-B27 positive, and not AS if HLA-B27 negative. In addition, the study also found that the onset of AS is related to gender and age, and the onset of AS is significantly higher in men than in women, and the peak age of onset is between 15 and 30 years old. How can I tell if I have ankylosing spondylitis? As we mentioned earlier, AS mainly affects the medial joints, including the sacroiliac joints, hip joints and spine. When a patient begins, the discomfort may be unilateral or intermittent stiffness and vague pain, but gradually develops into bilateral, persistent back pain and stiffness, especially at night, which can interfere with sleep and require movement to alleviate the pain before falling asleep again. In severe cases, patients may find it difficult to get out of bed, and the pain of AS is often worse after rest and less after activity. In some patients, the pain may not be in the lower back, but in the hip or buttocks unilaterally or bilaterally. In some cases, the pain may be unilateral or bilateral swelling and pain in the large joints of the lower limbs. In addition to joint involvement, AS also involves the eyes, cardiovascular system, lungs, and neuromuscular system. Acute anterior uveitis or iridocyclitis, which is characterized by pain, tearing and photophobia in the eyes, is the most common. ASAS2009 presents the latest diagnostic criteria for AS, which provide a more adequate basis for early diagnosis of AS. 1, ASAS2009 axial AS diagnostic criteria: low back pain for more than 3 months, age of onset <45 years old, meeting the following criteria: imaging sacroiliac arthritis + ≥1 SpA features or HLA-B27 positive + ≥2 SpA features to diagnose AS, sensitivity 82.9%, specificity 84.4%. The SpA features: inflammatory lower back pain, arthritis, adhesions, uveitis, finger/toe infections, psoriasis, Crohn's disease/ulcerative colitis, good response to NSAIDs treatment, family history of SpA, HLA-B27 positive, significantly elevated CRP. Imaging manifestations of sacroiliac arthritis: ①MR showed acute inflammatory reaction, highly suggestive of sacroiliac arthritis associated with SpA ②X-ray showed clear sacroiliac arthritis in accordance with the 1984 New York Revised AS criteria. 2, ASAS 2009 peripheral AS diagnostic criteria: for patients with arthritis (mainly asymmetric oligoarthritis of the lower extremities), adhesion point inflammation or finger (toe) inflammation, if they have ≥ 1 SpA feature or ≥ 2 other SpA features, they can be diagnosed as peripheral SpA. SpA features include uveitis, psoriasis, Crohn's disease, history of antecedent infection, HLA-B27 positivity, and imaging-confirmed sacroiliac arthritis; other SpA features include arthritis, enthesitis, phalangitis, inflammatory low back pain, and a family history of SpA. What is the treatment for ankylosing spondylitis? The treatment plan for AS varies depending on the type. For peripheral AS, traditional DMARDs such as methotrexate, lorazepam, leflunomide, and biologics are effective. In the case of mid-axis AS, a large body of evidence suggests that only NSAIDs and biologics are effective. The use of biologics in rheumatic diseases is a milestone in the treatment of rheumatic diseases. The most widely used and proven efficacy and the treatment protocols entered the international guidelines for rheumatic diseases are the application of TNF-α antagonists in the treatment of RA and AS. It is well known that TNF-α plays a crucial role in the pathogenesis of AS. Anti-TNF-α agents antagonize the pathogenic effects of TNF-α by directly inhibiting TNF-α or binding to TNF-α receptors, which can effectively improve the stiffness, pain, joint swelling and bone destruction of joints, substantially improve patients' symptoms and quality of life, delay disease progression, reduce disability and improve prognosis. ASAS 2009 recommends the use of TNF inhibitors for active AS if treatment with the two maximum recommended doses of NSAIDs for 4 weeks does not work. It can be seen that the efficacy of TNF-α inhibitors is self-evident, but why they are not widely used in China? The main reason is the high price of the drug. At present, four types of TNF-α antagonists have been marketed: adalimumab, classical gram, etanercept and Ixep, with prices ranging from a minimum of 500 yuan to a maximum of nearly 10,000 yuan, which is about 100,000 yuan for a year of treatment, which is indeed difficult for an ordinary family in China to afford. In response to this problem, many medical practitioners and economists have conducted studies and found that the use of biologics, in the short term, appears to be expensive and unaffordable for patients, but in the long term, the economic benefits of improvement and normal life far outweigh the economic burden of lost wages, treatment, nutrition and living expenses brought about by the disease, which strongly indicates that the benefits of biologics for AS outweigh the disadvantages.