Behterev's disease

Bechterew's disease is a chronic inflammatory disease of the spine (spondylitis) and sacroiliac joints (sacroiliitis), often accompanied by damage to peripheral joints (arthritis) and entheses (enthesitis), and in some cases the eyes (uveitis) and aortic bulb (aortitis).

Ankylosing spondylitis is better known as Bechterew's disease, although its fuller name is Strumpell-Bechterew-Marie disease. This disease has an autoimmune pathogenesis, has a chronic progressive course and can last for years and decades.

Ankylosing spondylitis, or Bechterew's disease, usually affects cartilaginous types of joints, mainly the sternoclavicular, costosternal, sacroiliac, hip and shoulder joints, and also affects small intervertebral joints. Healthy joint tissues are gradually replaced by fibrous scar tissue, and joint stiffness develops.

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Epidemiology

The prevalence of Bechterew's disease correlates with the frequency of detection of HLA-B27 in the population and varies (among adults) from 0.15% (Finland) to 1.4% (Norway). The disease develops mainly at the age of 20-30 years, and in men 2-3 times more often.

Quite often, Bechterew's disease occurs at a young age, around 20-30 years, and men are more often affected. There are many theories about the development of this disease, but the genetic theory is most often preferred. It is believed that Bechterew's disease has a hereditary predisposition due to the presence of the histocompatibility antigen HLA-B27, due to which the immune system perceives cartilage tissue as foreign and directs its immune response to them, causing inflammation, pain, limited movement and stiffness in the joints.

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How does Bechterew's disease develop?

The only generally accepted risk factor for the development of ankylosing spondylitis is genetic predisposition. More than 90% of patients have HLA-B27, one of the class I genes of the major histocompatibility complex. A relationship has been established between the frequency of this gene in different populations and the prevalence of the disease. However, the presence of HLA-B27 cannot be considered a sign of the obligatory occurrence of ankylosing spondylitis, and the disease does not develop in most carriers of this gene. According to family and twin studies, the share of HLA-B27 in the predisposition to the development of ankylosing spondylitis is no more than 20-50%. In addition, there are at least 25 alleles of HLA-B27 (B27001-B2723), differing from each other by only one nucleotide in the DNA composition and, accordingly, changes in 17 amino acids in the recognition groove of the protein. Not all HLA-B27 alleles are associated with predisposition to ankylosing spondylitis (e.g. B2706 in Southeast Asian countries or B2709 in Sardinia). The disease may also develop in the absence of this antigen. However, most hypotheses about the origin of ankylosing spondylitis are based on the assumption that HLA-B27 is involved in the pathogenesis of the disease.

There are two main hypotheses for the development of the disease.

1. The first of them is based on the assumption of the antigen-presenting function of the protein encoded by HLA-B27. It is known that this protein contains regions similar to epitopes of some enterobacteria (in particular, Klebsiella, Enterobacter, Shigella, Yersinia), as well as Chlamydia trachomatis. It is believed that due to this similarity, autoimmune reactions may occur with the appearance of antibodies and cytotoxic T-lymphocytes to one's own tissues (the phenomenon of molecular mimicry). Circulating antibodies cross-reacting with HLA-B27 and antigens of the indicated microorganisms, as well as cytotoxic T-lymphocytes, were found in patients with AS. However, there is no clinical evidence yet of the role of these immune reactions in the development of Bechterew's disease.
2. According to the second hypothesis, it is assumed that for some unknown reasons, abnormalities in the assembly of the heavy chain of the protein molecule HLA-B27 in the endoplasmic reticulum of cells may occur. As a result, the accumulation and degradation of conformationally altered molecules of this protein occur, which leads to the development of intracellular "stress" with excessive synthesis of proinflammatory mediators.

However, these hypotheses do not explain the absence of Bechterew's disease in most individuals with HLA-B27, as well as the predominant involvement of the spine, joints and entheses.

The peculiarity of the spinal lesion in Bechterew's disease is the inflammation of various structures: bone tissue (osteitis), joints (intervertebral, facet, costovertebral), as well as entheses (places of attachment of fibrous discs to the vertebral bodies, interspinous ligaments). In places of spinal inflammation, chondroid metaplasia occurs with subsequent ossification of these zones and ankylosis of damaged structures.

Arthritis in Bechterew's disease is morphologically non-specific, but has a characteristic localization; almost always, damage to the sacroiliac joints is noted, and the pathological process often involves the sternocostal and costovertebral joints, as well as the symphyses (symphysis of the manubrium of the sternum, pubic symphysis).

Bechterew's disease is characterized by inflammation of the entheses (the places where many ligaments, tendons, aponeuroses, and joint capsules attach to bones, primarily in the shoulder, hip, knee joints, and heel area), which contain fibrous cartilage.

Symptoms of Bechterew's disease

Very often there is a central form of the disease, when the spine is mainly affected. Bechterew's disease develops unnoticed by the patient, and for a long time it can make itself known only in the form of pain during exertion or active movements. The pain is initially localized in the sacrum and gradually moves up the spinal column. The patient's posture begins to change slowly, after a while it begins to take on a "supplicant pose" - the head tilts forward, the chin approaches the sternum, the thoracic spine becomes more convex to the back, a stoop appears, the arms are bent at the elbows, and the legs at the knees. For this form, as well as for all other forms, night pains and pain at rest are characteristic, and by the middle of the day the pain decreases, the person "walks around" and the pain is significantly reduced.

However, gradually the range of motion in the spine decreases, it is difficult for a person to bend forward, bend backwards, or bend to the sides. Over time, the gait begins to change significantly - this is due not only to damage to the spine, but also to the involvement of the hip joints in the process.

With the development of ankylosis - fusion of joints in the spine - turning the head to the side becomes difficult, in order to see what is happening behind, a person needs to turn the whole body. Bechterew's disease has one of the characteristic signs - the disappearance of the lumbar curve and the appearance of a strong stoop in the thoracic region.

In addition, Bechterew's disease has extra-articular symptoms - damage to the eyes, heart, kidneys. The disease mainly occurs in the form of exacerbations and remission phases, but it is still a chronic progressive disease.

Classification

The following forms of the disease are distinguished.

• Idiopathic Bechterew's disease.
• Secondary Bechterew's disease as one of the manifestations of other diseases from the group of seronegative spondyloarthritis (psoriatic arthritis, reactive arthritis, spondyloarthritis associated with nonspecific ulcerative colitis with Crohn's disease).

The causes of Bechterew's disease are unknown.

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Screening

Screening for individuals predisposed to developing ankylosing spondylitis is currently considered unjustified. However, screening for early detection of ankylosing spondylitis may be appropriate in individuals under 30 years of age with chronic low back pain who are likely to be at risk for developing the disease (e.g., acute unilateral anterior uveitis or a history of ankylosing spondylitis or other seronegative spondyloarthritis in first-degree relatives).

In what cases can one suspect Bechterew's disease?

Back pain for more than 3 months, especially if it intensifies after prolonged rest. The pain may radiate to the buttock, back of the thigh, groin, stiffness in the spine in the morning, muscle tension in the lumbar region, painful sensations in the chest muscles, a significant increase in ESR - up to 30 mm / hour.

As a rule, all patients with such complaints go to a rheumatologist or vertebrologist. The establishment of the correct diagnosis depends on them. The early diagnosis of Bechterew's disease and the appointment of further treatment depend on how well the examination was performed, the complaints were collected and the correct research methods were prescribed. The earlier the treatment was started, the more likely it is to extend the patient's working period, delay the onset of prolonged excruciating pain and the development of complications.

What diagnostic methods are needed?

This is an X-ray examination of the spine, MRI - magnetic resonance imaging, clinical blood and urine tests, biochemical blood analysis, blood for detection of the HLA-B27 antigen.

Bechterew's disease is a chronic inflammatory disease characterized by damage to the sacroiliac, synovial (intervertebral and costotransverse) and non-synovial (discovertebral) joints of the spinal column, as well as the attachment sites of ligaments and tendons to the vertebral bodies and gas bones. The primary sites of damage are the sacroiliac joints, thoracolumbar and lumbosacral spine. Subsequently, changes can be determined in all parts of the spine. Involvement of peripheral joints in the pathological process is moderately expressed. In this case, they talk about the peripheral form of Bechterew's disease. Changes in the hip and shoulder joints are encountered most often compared to other peripheral joints.

Sacroiliac joints

To diagnose Bechterew's disease, changes in the sacroiliac joints are required. The absence of sacroiliitis causes great difficulties in verifying this disease and casts doubt on the diagnosis. Very rarely, changes in the spine can occur without convincing radiographic symptoms of damage to the sacroiliac joints. In this case, dynamic monitoring of changes in these joints and differential diagnostics with other diseases from the group of seronegative sionodyloarthroses are required. Sacroiliitis in ankylosing spondylitis occurs at the earliest stages of the disease and is characterized in typical cases by bilateral and symmetrical spread.

Spine in Bechterew's disease

The primary sites of spinal lesions, especially in men, are the thoracolumbar and lumbosacral spine; in women, the cervical spine may be affected in the early stages of the disease. Anterior spondylitis, associated with local erosive changes in the anterior vertebral bodies and inflammation in the anterior longitudinal ligament of the spine, leads to a decrease in the concavity of the vertebral body.

The result of these changes is the typical for Bechterew's disease "squared" vertebral bodies, clearly visible on the lateral radiograph of the spine. These changes are found in the lumbar spine, since the thoracic vertebrae normally have a configuration approaching a rectangular one. Syndesmophytes are vertically oriented bone ossifications located outside the fibrous ring of the intervertebral disc. They prevail in the area of the anterior and lateral parts of the vertebral bodies and form bone bridges between the vertebral bodies. In the late stages of the disease, multiple syndesmophytes are connected to each other over a large area and form a "bamboo" spine characteristic of Bechterew's disease. It is important to note the fact that syndesmophytes. characteristic of ankylosing spondylitis, as well as enterogenous spondylitis, differ from syndesmophytes and osteophytes found at the corners of the vertebral bodies in other diseases. They have a clear, even contour, smoothly passing from one vertebral body to another. Osteophytes in deforming spondylosis are triangular in shape, have the shape of a "jug handle" up to 10 mm long, located at the anterior and lateral corners of the vertebral bodies. In diffuse idiopathic bone hyperostosis of the spine (Forestier syndrome), calcification of the anterior longitudinal ligament is found over a large area with the formation of coarse, deformed osteophytes on the anterior and lateral angles of the vertebral bodies with a wall thickness of up to 4-6 mm and a length of up to 20-25 mm, which is how they differ from syndesmophytes in AS, the width of which does not exceed 1-2 mm. In addition, in ankylosing hyperostosis, there are no changes in the sacroiliac joints. Erosion of the articular surfaces and narrowing of one or more intervertebral discs (spondylodiscitis) are characteristic radiographic symptoms of Bechterew's disease. These changes can be divided into local and widespread. The outcome of spondylodiscitis may be calcification of the intervertebral disc, and if spondylodiscitis is combined with destructive changes in the articulating bodies of the vertebrae, then in this case the formation of bone ankylosis of adjacent vertebrae is possible. Intervertebral joint lesions occur later, but ankylosis may also be the outcome of arthritis. In addition to lesions of the anterior longitudinal ligament, ossification of the posterior longitudinal and interosseous ligaments of the spine is detected. Erosions in the area of the odontoid process and atlantoaxial subluxation can be detected in Bechterew's disease, although with a lower frequency than in RA. Ankylosis in the area of the atlantoaxial joint can also be found. In other parts of the cervical spine, changes, if they are detected, are identical to those found in the thoracolumbar spine.

A distinctive characteristic of radiological changes may be a combination of erosive and proliferative changes in the places of ligament attachment, which makes it possible to conduct differential diagnostics with other inflammatory and non-inflammatory diseases, and to diagnose Bechterew's disease.

However, it is worth saying that there are no specific diagnostic signs of the presence of ankylosing spondylitis, there is only a complex of symptoms and data from laboratory and other types of studies that allow us to exclude other diseases, for example, rheumatoid arthritis, and reliably establish a diagnosis of Bechterew's disease.

Treatment of Bechterew's disease

Treatment of Bechterew's disease is only complex. This includes drug therapy, exercise therapy, sanatorium treatment, and even, if necessary, surgical intervention. Medications are mainly aimed at relieving pain and reducing inflammation. For this purpose, non-steroidal anti-inflammatory drugs are used, such as ibuprofen, indomethacin, diclofenac sodium, etc. But a large role is still given to exercise therapy and, in general, the motor activity of the sick person.

A physical therapy doctor can offer the patient an individual set of exercises that will help relieve stiffness, increase range of motion, strengthen muscles, give more flexibility to joints and relieve pain. At first, the exercise will have to be done while overcoming pain, but gradually it will become less, range of motion will increase, and stiffness will decrease. Of course, physical therapy is not a panacea, but its huge role in this disease cannot be denied.

People diagnosed with Bechterew's disease, but who continue to maintain their physical fitness and those who lead an active lifestyle, can maintain their ability to work for a much longer period of time and delay the development of complications.

Prevention

It is not possible to prevent Bechterew's disease. Medical genetic counseling can be performed to determine the risk of the disease in a child born to parents with the disease.