What is Ankylosing Spondylitis?

Ankylosing spondylitis (AS) is a disease whose main symptoms are inflammation of sacroiliac joints and spinal attachment points. Strongly associated with HLA-B27. Certain microorganisms (such as Klebsiella) share common antigens with susceptible individuals' tissues and can trigger abnormal immune responses. It is a chronic inflammatory disease characterized by large joints of the extremities, and fibrosis and ossification of the intervertebral disc fibrous rings and nearby connective tissue, as well as joint ankylosis. Ankylosing spondylitis belongs to the category of rheumatism. The etiology is not clear. It is a chronic disease with the spine as the main lesion. It involves the sacroiliac joints, causes spinal rigidity and fibrosis, and causes different degrees of eye, lung, muscle, and bone disease. Immune disease.

Basic Information

English name: ankylosing spondylitis
Visiting department: Division of Rheumatology

Multiple groups: Young men
Common causes: Related to environmental, genetic, immune, metabolic and other factors
Common symptoms: The spine is particularly marked by lumbosacral lesions

Causes of ankylosing spondylitis

It is likely to be affected by environmental factors (including infections) and other factors based on genetic factors. Genetic factors play an important role in the pathogenesis of AS. It is generally believed to be directly related to HLA-B27. The incidence of AS in HLA-B27 positive patients is 10% to 20%. Immune factors are also one of the causes. Some people have found that serum complement is increased in 60% of AS patients, and most cases have IgA type wet Factors, serum C4 and IgA levels were significantly increased. Trauma, endocrine, metabolic disorders, and allergies are also suspected as pathogenesis factors.

Clinical manifestations of ankylosing spondylitis

Initial symptoms

For young people aged 16 to 25, especially young men. Ankylosing spondylitis is generally insidious, without any clinical symptoms at an early stage, and some patients may show mild systemic symptoms at an early stage, such as fatigue, weight loss, chronic or intermittent hypothermia, anorexia, and mild anemia. Because the condition is relatively mild, most of the patients cannot be detected early, resulting in delay of the condition and loss of the best opportunity for treatment.

2. Joint disease manifestations

Most AS patients have joint disease, and most of them invade the sacroiliac joint first, and then progress to the cervical spine. A small number of patients are affected by the cervical spine or several spinal segments at the same time, and can also invade the surrounding joints. Early joints have inflammatory pain, accompanied by muscle spasms around the joints, and a sense of stiffness, which is obvious in the morning. Can also be expressed as night pain, relieved by activity or taking analgesics. With the progress of the disease, joint pain is reduced, and the spine segments and joints are restricted and deformed. In the later stage, the entire spine and lower limbs become stiff bows and flex forward.

(1) Sacroiliitis Arthritis About 90% of AS patients first present with sacroiliitis. Later, it progressed to the cervical spine, showing recurrent back pain, stiffness in the lumbosacral region, intermittent back or bilateral back pain and hip pain on both sides, which can be radiated to the thighs, no positive signs, and negative leg elevation test. But pressing or stretching the sacroiliac joint directly can cause pain. Some patients have no symptoms of sacral arthritis, and only X-rays have revealed abnormal changes. About 3% AS was first affected by the cervical spine, and then descended to the lumbosacral region. 7% AS was involved in almost the entire spine at the same time.

(2) Lumbar spine lesions When the lumbar spine is affected, most of them are restricted in lower back and waist movement. Waist flexion, dorsiflexion, side bending, and rotation can be restricted. Physical examination revealed lumbar spinal process tenderness, spasms of the lumbar paraspinal muscles, and atrophy of lumbar muscles at later stages.

(3) Thoracic spine lesions When the thoracic spine is involved, it manifests as back pain, anterior and lateral chest pain, and the most common form is kyphosis. If the rib vertebrae, sternal stalk joints, sternoclavicular joints and intercostal cartilage joints are involved, there is a girdle-like chest pain, restricted thorax expansion, and increased chest pain when inhaling, coughing or sneezing. In severe cases, the thoracic cage remains in exhalation, and the thoracic expansion is reduced by more than 50% compared with normal people, so only abdominal breathing assistance can be used. Due to the reduction in the volume of the chest and abdomen, cardiopulmonary and digestive dysfunctions are caused.

(4) Cervical spondylosis A few patients first showed cervical spondylitis, with cervical pain first, and radiated along the neck to the head and arm. The neck muscles start with spasms and then atrophy, and the disease progresses to cervical thoracic kyphosis. Head movements are significantly limited, often fixed in the forward flexion position, and cannot be tilted, bent or turned. In severe cases, they can only see the small ground in front of their toes, and cannot look up.

(5) Peripheral joint disease Approximately half of AS patients have transient acute peripheral arthritis, and approximately 25% have permanent peripheral joint damage. Usually occurs in large joints, lower limbs than upper limbs. When the shoulder joint is involved, the joint movement is limited, the pain is more obvious, and the activities such as combing hair and raising hands are limited. When the knee joint is violated, the joint is flexibly curved, making daily life such as walking and sitting more difficult. Rarely violates elbow, wrist and foot joints.

In addition, the pubic symphysis can also be affected. The upper edge of the pelvis, the ischial tuberosity, the trochanter of the femur, and the heel may have osteitis symptoms. The early manifestations are local soft tissue swelling and pain, and the late stage is bony. Generally, peripheral arthritis can occur before or after spondylitis. Local symptoms are not easily distinguished from rheumatoid arthritis, but there are fewer residual deformities.

3. Extra-articular manifestations

Most of the extra-articular lesions of AS occur after spondylitis, with occasional extra-articular symptoms months or years before skeletal muscle symptoms. AS can affect multiple systems throughout the body and is associated with multiple diseases.

(1) Heart disease Aortic valve disease is more common. About 1% of patients with aortic valve insufficiency are clinically affected; about 8% of cardiac conduction block occurs, which can coexist with or separate from aortic valve insufficiency, and severe cases occur due to complete atrioventricular block S syndrome. Angina can occur when the lesion affects the coronary artery orifice. A minority of aortic fibroids, pericarditis, and myocarditis occur.

(2) Long-term follow-up of eye diseases , 25% of AS patients have conjunctivitis, iritis, uveitis, or uveitis, which may occasionally be accompanied by spontaneous anterior chamber hemorrhage. Iriditis is easy to recur. The longer the disease is, the higher the incidence is, but it has nothing to do with the severity of spondylitis. It is common in peripheral arthropathy, and a few can occur before spondylitis. Eye diseases are often self-limiting and sometimes require treatment with corticosteroids, and some can cause glaucoma or blindness without proper treatment.

(3) Ear lesions The AS patients with chronic otitis media have significantly more extra-articular manifestations than those without AS.

(4) Pulmonary lesions A small number of AS patients may be complicated with speckle-shaped irregular fibrotic lesions of the lung lobe at the later stage, which manifests as sputum, asthma, or even hemoptysis, and may be accompanied by recurrent pneumonia or pleurisy.

(5) Nervous system diseases Due to spinal rigidity and osteoporosis, cervical dislocation and spinal fractures are easy to occur, which leads to spinal cord compression. If discitis occurs, severe pain is caused. The late stage of AS can invade the cauda equina and cause cauda equina syndrome, resulting in pain in the lower limbs or hip nerve roots, loss of sensation in the sacral nerve distribution area, weakened Achilles tendon reflexes, and motor dysfunction such as the bladder and rectum.

(6) Amyloidosis is a rare complication of AS.

(7) Renal and prostate lesions Compared with RA, renal impairment is rare in AS, but IgA nephropathy has been reported. Chronic prostatitis complicated by AS is higher than that of the control group, and its significance is unknown.

Ankylosing spondylitis

1. Computer tomography (CT)

For patients with clinical suspicion who cannot be diagnosed with X-rays, a CT examination can be performed, which can clearly show the sacroiliac joint space, and is unique in determining whether the joint space is widened, narrowed, rigid, or partially rigid.

2. Magnetic resonance (MRI) and single photon emission computed tomography (SPECT)

Researchers believe that MRI and SPECT scintigraphy of sacroiliac joints are very helpful for very early diagnosis and treatment. From this perspective, it is significantly better than ordinary X-rays, but it is expensive and is not recommended as a routine examination.

3. Laboratory inspection

The white blood cell count is normal or elevated, the proportion of lymphocytes is slightly increased, a few patients have mild anemia (positive cell hypopigmentation), and the erythrocyte sedimentation rate can be increased, but the correlation with disease activity is not significant, while C-reactive protein is more meaningful . Serum albumin decreases, 1 and globulin increase, serum immunoglobulin IgG, IgA, and IgM can increase, and serum complements C3 and C4 often increase. Alkaline phosphatase is elevated in about 50% of patients, and serum creatine phosphokinase is often elevated. Serum rheumatoid factor was negative. Although 90% to 95% of AS patients are positive for HLA-B27, HLA-B27 is generally not used to diagnose AS, and HLA-B27 is not routinely tested.

4.X-ray inspection

It is of great significance for the diagnosis of AS. X-ray changes of sacroiliac joints are early in 98% to 100% of cases, which is an important basis for the diagnosis of this disease. Early X-ray manifestations are sacroiliitis, and the lesions generally begin in the middle and lower part of the sacroiliac joint and are bilateral. Begin to invade the metatarsal side, and then invade the metatarsal side. Speckled or massive, visible on the metatarsal side. It can then invade the entire joint, with jagged edges, bone hardening under the cartilage, bone hyperplasia, and narrowing of the joint space. Eventually the joint space disappeared and bony rigidity occurred. The diagnostic criteria for sacroiliitis arthritis are divided into five stages: grade 0 is normal sacroiliac joints, stage is suspicious sacroiliac arthritis, and stage is blurry sacroiliac joint edges, with slight sclerosis and minimally invasive lesions. Changes, stage III is moderate or progressive sacroiliitis, accompanied by one (or more) changes: near joint area sclerosis, joint space narrowing / widening, bone destruction or partial rigidity, stage IV is complete joint fusion With or without rigidity.

X-ray manifestations of spinal lesions are early general osteoporosis, blurry (decalcified) vertebral joints and vertebral bone trabeculae, vertebral bodies are "square vertebrae", normal lumbar vertebrae disappear and straighten, which can cause Compression fracture of one or more vertebral bodies. The lesions developed to the thoracic and cervical intervertebral facet joints, calcification of the disc space, calcification of the annulus fibrosus and anterior longitudinal ligament, ossification, and ligament osteophyte formation, associating adjacent vertebrae and forming intervertebral bone bridges. Characteristic "Bamboo-like spine". Primary X-ray and similar spondylitis secondary to inflammatory bowel disease, Reiter syndrome, and psoriatic arthritis are similar, but the latter is asymmetric ankylosing. Bony erosion and periostitis can occur in the ligaments, tendons, and bursal attachments, most commonly seen in the calcaneus, ischial tuberosity, and sacral condyle. Similar X-ray changes can occur in other peripheral joints.

Ankylosing spondylitis diagnosis

Clinical manifestation

(1) Soreness and discomfort in the waist and / or spine, groin, buttocks, or lower limbs, or asymmetric peripheral oligoarthritis, especially lower extremity oligoarthritis, which lasts for more than 6 weeks.

(2) Pain at night or morning stiffness is obvious.

(3) Remission after the activity.

(4) Heel pain or other tendon attachment points.

(5) Clinical manifestation or past history of iris ciliary body inflammation.

(6) AS family history or HLA-B27 positive.

(7) Non-steroidal anti-inflammatory drugs (NSAIDs) can quickly relieve symptoms.

2. Imaging or pathology

(1) Bilateral X-ray iliac arthritis stage III.

(2) Bilateral CT sacroiliitis arthritis .

(3) MRI examination is available for those with CT or arthritis deficiency of grade II. Such as showing cartilage destruction, edema of the joint and / or extensive fat deposition, especially the dynamic enhancement examination of joints or joints with enhanced strength> 20% and enhanced slope> 10% / min.

(4) Pathological examination of sacroiliac joint showed inflammation.

3. Diagnosis

A diagnosis of AS can be made if it meets the clinical criteria No. 1 and 3 of the other criteria, and any of the imaging and pathological criteria.

Differential diagnosis of ankylosing spondylitis

(I) Identification of common diseases

Strain of lumbosacral joint

Chronic lumbosacral joint strain is persistent and diffuse low back pain, with the lumbosacral region being the heaviest, the spine movement is not restricted, and there is no special change in X-rays. Acute lumbosacral joint strain, pain aggravated by activity, can be relieved after rest.

2. Osteoarthritis

It often occurs in the elderly, and is characterized by degeneration and hypertrophy of bones and cartilage, thickening of the synovium, and damage to the joints such as the spine and knee joints. Chronic low back pain is often the main symptom in patients with spine, which is easy to be confused with AS. However, the disease does not cause joint ankylosis and muscle atrophy, and there are no systemic symptoms. X-rays show osteophyte formation and narrowing of the intervertebral space.

3.Forestier disease (senile joint ankylosing bone hypertrophy)

A continuous osteophyte also occurred in the spine, similar to AS's spinal bamboo-like changes, but the sacroiliac joint was normal and the intervertebral facet joints were not invaded.

4. Tuberculous spondylitis

Clinical symptoms such as spinal pain, tenderness, stiffness, muscle atrophy, kyphosis, fever, and rapid erythrocyte sedimentation are similar to AS, but X-ray examination can be used for identification. In tuberculous spondylitis, the edges of the spine are blurred, the intervertebral space is narrowed, the anterior wedge is deformed, there is no ligament calcification, and sometimes there is a shadow of paraspinal tuberculosis abscess, and the sacroiliac joint is unilaterally affected.

5. Rheumatoid arthritis

It has been confirmed that AS is not a special type of RA, and there are many differences between the two that can be identified. RA women are more common, usually invading the small joints of the hands and feet, and bilateral symmetry. The sacroiliac joints are generally not affected. For example, the spine is invaded, many are invaded the cervical spine, and there is no calcification of paravertebral ligaments. RF is often positive, and HLA-B27 antigen is often negative.

6. Enteric arthropathy

Spondylitis can occur in ulcerative colitis, Crohn's disease, or enteric lipodystrophy (Whipple), and the affected joints and X-ray changes of the intestinal arthropathy are similar to AS and not easily distinguishable, so it is necessary to find intestinal symptoms and signs To identify. Ulcerative colitis includes colonic mucosal ulcers, edema, and bloody diarrhea. Crohn's disease has abdominal pain, malnutrition, and fistula formation. Whipple disease has fatty diarrhea, sharp weight loss, etc. These all help to diagnose the primary disease. Enteropathic arthropathy has a low HLA-B27 positive rate, and the IgG in the intestinal perfusate of Crohn's patients increases, while the IgG in the intestinal perfusate of AS patients is basically normal.

7. Reiter syndrome and psoriatic arthritis

Spondylitis and sacral arthritis can occur in both diseases, but spondylitis generally occurs later and is milder, with less calcification of the paravertebral tissues, and the ligament osteophytes are mainly non-marginal (calculus of fibrous tissue outside the annulus fibrosus). The formation of a partial bone bridge between two adjacent vertebral bodies is different from the bamboo-like spine of AS. Sacral arthritis is generally unilateral or bilateral asymmetrical damage, while silver arthritis has skin psoriasis damage and can be identified.

8. Tumor

Tumors can also cause progressive pain, requiring a comprehensive examination and a clear diagnosis to avoid misdiagnosis.

9. Acute rheumatic fever

The initial clinical manifestations of some patients are similar to acute rheumatic fever, or large joint swelling and pain, or long-term low fever and weight loss. It is not uncommon to have high fever and acute inflammation of peripheral joints as the first symptoms. Such patients are more common in adolescents, but also Easy to be misdiagnosed for a long time.

10. Tuberculosis

Individual patients are similar to tuberculosis at the beginning, showing low fever, night sweats, weakness, fatigue, weight loss, anemia, and sometimes with unilateral hip arthritis, which is easily misdiagnosed as tuberculosis. Relevant TB tests can be identified.

(Two) identification with sero-negative spinal arthropathy

1. Reiter syndrome and psoriatic arthritis

Spondylitis and sacral arthritis can occur, but spondylitis generally occurs later and is lighter. There is less calcification of the paravertebral tissues. The ligament osteophytes are mainly non-marginal (calculus of fibrous tissue outside the annulus fibrosus). The formation of partial osteoporotic bridges is different from the bamboo-like spine of ankylosing spondylitis. Sacral arthritis is generally unilateral or bilateral asymmetry, spinous process joint disease is rare, and there is no universal osteoporosis. In addition, Reiter syndrome has conjunctivitis, urethritis, and mucosal skin damage, and psoriatic arthritis has skin psoriasis damage.

2. Enteric arthritis

Spondylitis can occur in ulcerative colitis, Crohn's disease, and enteric lipodystrophy (Whippe), and the affected joints and X-ray changes of intestinal arthropathy are similar to ankylosing spondylitis, so it is necessary to find the intestine Symptoms and signs to identify. Ulcerative colitis includes colonic mucosal ulcers, edema, and bloody diarrhea; Crohn's disease has abdominal pain, nutritional disorders, and sacral canal formation; Whipple disease has fatty diarrhea; The HLA-B27 positive rate of enteric arthropathy is low. The IgG in the intestinal perfusate of patients with Crohn disease is increased, while the IgG in the intestinal perfusate in patients with ankylosing spondylitis is basically normal.

3. Reactive arthritis

Often secondary to infections in other parts of the body, infections can usually be found, and antibiotics are effective.

Ankylosing spondylitis treatment

1. The purpose of controlling AS treatment

It is to control inflammation, reduce or relieve symptoms, maintain normal posture and optimal functional position, and prevent deformities. To achieve the above goals, the key lies in early diagnosis and early treatment, and taking comprehensive measures for treatment, including educating patients and their families, physical therapy, physical therapy, medicine and surgical treatment.

(1) The treatment of this disease starts by educating patients and their families to understand the nature, approximate course, possible measures and future prognosis of the disease, in order to enhance the confidence and patience of disease resistance, and to obtain their understanding and close cooperation.

(2) Pay attention to maintaining normal posture and mobility in daily life, such as walking, sitting and standing with your chest closed and abdomen, sleeping without a pillow or thin pillow, sleeping on a hard wooden bed, taking a supine or prone position, morning and evening Prone for half an hour. Participate in labor and sports activities within your ability. Pay attention to posture during work to prevent spinal deformities.

(3) Maintain optimism, eliminate tension, anxiety, depression, and fear; quit smoking and drinking; work on time and participate in medical sports.

(4) Understand the effects and side effects of drugs, learn to adjust the dosage of drugs and deal with side effects of drugs, in order to cooperate with treatment and achieve better results.

2. Physical therapy

Physical therapy is good for all kinds of chronic diseases, and it is even more important for AS. Can maintain the physiological curvature of the spine and prevent deformities. Maintain chest movement and maintain normal breathing function. Maintain bone density and strength, prevent osteoporosis and disuse muscle atrophy. Patients can take appropriate exercise methods and exercises according to their personal circumstances. If the new pain persists for more than 2 hours and cannot be recovered, it indicates excessive exercise and the amount of exercise should be appropriately reduced or the exercise method adjusted.

3. Physical therapy

Physiotherapy can generally use thermal therapy, such as hot water bath, water bath or shower, mineral spring bath, etc., to increase local blood circulation, relax muscles, reduce pain, help joint activities, maintain normal function, and prevent deformities.

4. Drug treatment

(1) Non-steroidal anti-inflammatory drugs have anti-inflammatory and analgesic effects, reduce stiffness and muscle spasm. Side effects are gastrointestinal reactions, kidney damage, and prolonged bleeding time. Special attention should be paid to pregnant and lactating women.

(2) sulfasalazine SSZ is an azo complex of 5-aminosalicylic acid (5-ASA) and sulfasalazine (SP). It has been used in the treatment of AS since the 1980s. Side effects were mainly gastrointestinal symptoms, rashes, blood changes, and liver function changes, but they were rare. Blood medication and liver and kidney function should be checked regularly during medication.

(3) Methotrexate It is reported that the efficacy is similar to SSZ. Oral and intravenous medications have similar effects. Side effects include gastrointestinal reactions, bone marrow suppression, stomatitis, hair loss, etc. Periodically check liver function and blood signs during medication, and avoid drinking.

(4) Adrenal corticosteroids Generally, adrenal corticosteroids are not used to treat AS, but when NSAIDs are not effective in treating acute irisitis or peripheral arthritis, local injection or oral CS can be used.

(5) Tripterygium glycosides have anti-inflammatory and analgesic effects and are convenient to take. Side effects include gastrointestinal reactions, leukopenia, menstrual disorders, and reduced sperm motility, etc., which can be recovered after drug withdrawal.

(6) Biological preparations Tumor necrosis factor (TNF-) antagonists (such as Yisaipu, adalimumab, etc.) are currently the best choice for the treatment of spinal joint diseases such as AS, those who have the conditions should try to choose.

5. Surgical treatment

Severe spinal kyphosis and deformity can be corrected after the condition is stable. Lumbar vertebrae can be corrected with spinal osteotomy. The osteotomy of 7 chests and 1 neck can correct severe cervical deformity.

Ankylosing spondylitis prevention

1. Avoid heavy weight bearing to aggravate the lesion. Avoid maintaining a posture for a long time. When sitting for a long time, get up for at least ten minutes every hour. Do not use low back restraints (which reduce movement) to worsen spondylitis.

2. Avoid pillows and soft beds when sleeping. When sleeping, it is best to lie flat with your back upright.

3. When getting up in the morning when the spine is stiff, you can use hot water to improve it. Hot compresses are also partially effective in relieving local pain. Do not smoke to avoid causing lung injury.

4. Be careful of trauma, be sure to wear a seat belt when driving, try not to ride a motor vehicle.

5. In cold and humid seasons, prevent recurrence of symptoms.

6. Gastrointestinal and urinary tract infections often induce spondylitis, so you should pay attention to diet hygiene, drink plenty of water, eat more fruits and vegetables, and avoid urination and constipation.

7. Note whether other family members have symptoms of ankylosing spondylitis, such as back pain, morning stiffness, etc. If so, seek medical advice as soon as possible.