Axial spondyloarthritis: What are the causes of the inflammation, its manifestations and treatment?

Axial spondyloarthritis: What are the causes of the inflammation, its manifestations and treatment?
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Axial spondyloarthritis is a rheumatic inflammatory disease. It affects the axial part of the body, namely the spine and pelvis. However, disease changes can also be found in other areas of the body.


Axial spondylarthritis is a chronic rheumatic inflammatory disease . It mainly affects the axial part of the locomotor system, according to which it is also marked axial - axial = axial.

More precisely, it is the spine and SI joints - sacroiliac joints.

However, like other spondyloarthritis, and thus rheumatic diseases, disease changes affect other parts of the body .

Impacts of the joints of the lower limbs are described to a greater extent, including damage to the bone and also to the surrounding soft structures, such as cartilage and tendon attachments. Plus, the present feature may be swelling of the fingers.

Inflammation of the lesion = enthesitis. 
Swelling of the fingers = dactylitis. 

Bone tissue is affected by thinning density, ie osteoporosis, and bone destruction is accompanied by new bone formation, ie the formation of various growths.

Also read the article: Bone thinning .

In the case of non-bone damage, it involves the skin , eyes and intestines .

Spondyloarthritis can occur in several clinical forms, such as:

  • ankylosing spondylitis
  • reactive spondyloarthritis
  • psoriatic arthritis
  • arthritis associated with non-specific intestinal inflammation, so-called enteropathic arthritis
  • juvenile spondyloarthritis
  • nonspecific spondyloarthritis

In this group of spondyloarthritis, there is an association with evidence of HLA-B27 antigen .
At the same time, however, the presence of elevated serum rheumatic factor has not been demonstrated .

You ask: What is the HLA-B27 antigen?


HLA = in humans is the major histocompatibility complex from  M ajor h istocompatibility c omplex MHC .

An important ability of the body to recognize the body's own or damaged and foreign substances .

The HLA system is located on the short arm of chromosome 6. It is also referred to as the human antigen leukocyte complex - H uman L eukocyte A ntigen -  HLA .

In the immune response, it helps to differentiate the body's own substances  from foreign ones, such as bacteria and viruses. 

We know several types of HLA - A, B, C, D, DR. HLA-B subsequently has other sub-types.

HLA-B antigen  is a membrane antigen that is present in various autoimmune diseases. An antigen is a substance that is responsible for the production of antibodies and the body's immune response.

HLA-B27 occurs in Bechterev
disease , in autoimmune thyroiditis (inflammation of the thyroid gland) HLA-B8,
in psoriasis HLA-Cw6,
multiple sclerosis HLA-DR2,
in celiac disease HLA-DQ2 ... 

You will find interesting information in the expert article HLA-system and rheumatic diseases  (pdf format). 

Axial spondyloarthritis - AxSpA

This type is called spondyloarthritis (SpA), which exceeds the involvement of the SI area of ​​the joints and spine .

The estimated prevalence in the population is 1-2%. 

The form that predominates in arthritis, damage to the tendons, and swelling of the fingers is referred to as peripheral spondylarthritis .

In the case of axial spondyloarthritis, two types are determined, according to the provability on a classic X-ray .

1. Non-radiographic form and also  Axial spondyloarthritis without radiological evidence of AS (Ankylosing spondylitis).

2. The radiographic form  is termed and is known as ankylosing spondylitis . X-rays show inflammation and damage to the spine.

It affects men more often. 

International Society ASAS ( A ssessment of S pondylo A rthritis International S ociety) divided spondyloarthritis the axial and peripheral forms. 

The axial includes ankylosing spondylitis, with changes in X-ray findings, and  non- radiological AxSpA , also referred to as non-radiographic axial spondyloarthritis - nr-axSpA .

Thus, it is a disease characterized by symptoms of rheumatic disease , but no changes in the common X-ray findings in the spine and sacro-iliac joint have been present.

Axial spondylarthritis = early stage of autoimmune spinal inflammation.

Brief information about the spine and SI joint

The spine has a supporting and locomotor meaning for the body. The support of the body because it carries the entire weight of the body and is also important for movement. 

It consists of small bones, namely vertebrae. By interconnecting them, a functional apparatus is formed. 

Man has 33 or 34 vertebrae. 

And according to location, they are marked as:

  1. cervical vertebrae - 7 vertebrae, referred to as vertebrae C ervicales C1 to C7
  2. thoracic vertebrae - 12 thoracic vertebrae, to which the ribs are attached,
    vertebrae Th oracicae  Th1 to Th12
  3. stem vertebrae - vertebrae L1 to L5 , i.e. vertebrae L umbales
  4. sacral vertebrae - 5 to 6 vertebrae, S1 - S5 or (S6) = vertebrae S acrales 
    form sacrum - sacrum axis
  5. coccyx - 4  or 5 vertebrae vertebrae Co ccygeae Co1 - Co4 (Co5)

The vertebrae are interconnected by several mechanisms and structures.

It is a connection via:

A. Intervertebral joints , which are small articular surfaces that allow the spine to move. They are located on the articular process of the vertebra (procesus articulares), behind the leg of the vertebra (pedicle). The joint contains cartilage.

Intervertebral, facet joints are responsible for movement, its extent and also for the stability of the spine.

B. Intervertebral discs are placed between vertebrae that connect to each other. These are shock absorbers .

Plus other physical forces (tensile or compressive) arising during movement. These spread over the entire surface of the vertebra. In addition to mobility, they are also responsible for the stability of the spine. 

They contain a ring and a core . With uneven and long-term loading, there is a risk of a game disc .

For more interesting information about disks, see the article Arching the Intervertebral Disc .

C. The ligaments , i.e. ligaments = ligament apparatus , are placed between adjacent vertebrae and are referred to as short ligaments . Subsequently, the spine is strengthened and connected by long ligaments , present along the length.

D. The muscles of the back and the muscular corset  are involved in posture as well as movement. These are paravertebral muscles that form a firm and flexible component of the connection.

Muscles of the torso, such as the diaphragm, abdominal muscles, muscles of the back, pelvic floor and lower limbs, are an important part of posture formation, human posture and movement mechanisms.

E. Special connections are connections located in the section of the sacral spine and coccyx. For example, the joints between the crossbones ossify . The vertebrae are ingrown, ie immobile, forming a sacrum.

SI joints are sacroiliac joints

Sakro - iliac joints = cross  - hips  =  form a connecting spine and pelvis .

Their shape is irregular and uneven with many edges and depressions . They are compared in shape to the ear.

They mainly have a  stabilizing function . There is only minimal movement in the joint in the range of 2 to 4 millimeters

Until recently, they were considered a completely immovable connection.

They participate in ensuring the statics and balance of the human body during movement, between the spine, pelvis and lower limbs.

This part of the body is exposed to high static and dynamic loads. SI joints absorb shocks and tension. They transmit physical forces from the upper body to the hip joints and lower limbs.

In part responsible for pain localized in the lower back and rump .
For more information, see the article: SI Joint Block


The causes of the disease are unknown .

Genetic influence and the presence of HLA-B27 antigen are important . The co-participation of genetic predisposition + bacterial agents and environmental factors is also considered . Also read rheumatoid arthritis .

It states:
Approximately every third person with a positive HLA-B27 antigen is diagnosed with AxSpA.

Axial spondylarthritis is an autoimmune disease, which means that an exaggerated and diseased immune response to the body's own cells plays a role . It is not an inflammatory reaction caused by an infection.

The presence of HLA-B27 antigen and the concomitant absence of rheumatic factors play a role in the diagnosis.

In the case of non-radiographic axial spondyloarthritis, the involvement of men and women is reported to be uniform . Only in some cases does it progress to ankylosing spondylitis, which is more common in men.

Ankylosis = a
disease process that results in a ligament or bone junction .
This replaces the original healthy tissue. 
stiffness and loss of mobility of the joint or spine. 


Symptoms of the disease are dominated by pain in the back , stem, lower back and the surrounding area. 


Back pain is in most cases an acute problem . It is associated with muscle stiffness, movement disorders with deterioration in intensity during movement. Plus, the difficulties subside in a short time.

The opposite is chronic pain . At the same time, only a part of the whole acute problems passes into long-term ones. We also write about back pain in the article: Vertebrogenic Algic Syndrome .

And it is stated that ...

Axial spondyloarthritis is present in only five percent of the group of prolonged disorders .

Inflammatory pain is typical in axial spondylarthritis .

Inflammatory pain is characterized by :

  • resting pain
  • with the highest intensity
    • at night 
    • during sleep
    • pain awakens from sleep
    • in the morning after waking up
  • morning stiffness of joints, spine
  • pain is alleviated by activity , activity, warming up

Pain most often occurs in the area of ​​the stems , lower back , hip joints and in the upper area of ​​the sciatic muscles - buttocks = lower region of the spine.
Total embarking difficulty slowly , tediously , they have a creepy, yet durable character .

The onset of difficulties occurs at a young age ,
from the age of 25
before the age of 45

The ASAS group lists 5 criteria for inflammatory back pain :

  1. less than 40 years at the onset of the first symptoms of the disease
  2. slow and prolonged onset , not severe sharp pain as in radiculopathy
  3. improvement after warming up
  4. without relief at rest , on the contrary, an increase in intensity
  5. pain present at night , awakens from sleep

Of which at least 4 symptoms = inflammatory pain.

These problems are said to be accompanied by:

  • involvement of tendon attachments , ie  enthesitis
    • often the Achilles tendon
  • joint involvement - arthritis
    • knees, like swelling of the knee
    • hip joints
    • shoulders
  • eye inflammationuveitis
    • burning and cutting eyes
    • redness
    • excessive tearing
    • visual disturbances - blurred vision
    • photophobia - sensitivity to light
  • non-specific intestinal inflammation
    • stomach ache
    • indigestion
    • the presence of ulcerative colitis, Crohn's disease
    • reportedly up to 50% of those affected with spondyloarthritis
  • presence of psoriasis
  • also dactylitis (inflammation and swelling of the fingers)
  • general fatigue
  • sore throat

Bones can be affected by osteoporosis , which is  thinning of the bone tissue . In this case, there is a risk of fracture , even in the case of a minor injury. A serious condition is a fracture, a fracture of the spine - vertebrae.


Diagnosis of the disease relies on several methods. The history is important first . Clinical signs and physical examination

The information obtained from the baseline test will support the laboratory test and the detection of the HLA-B27 antigen

Evidence of HLA-B27 is reported to be present in:
90-95% of people with ankylosing spondylitis,  
80% of those with axial spondyloarthritis, 
60% of people with peripheral spondyloarthritis.

At the same time, however, there are facts that 8-10 percent of people with a positive HLA finding do not have spondyloarthritis .

Therefore, evidence of the presence of HLA alone is not sufficient to establish a diagnosis.

Optionally, CRP, a C-reactive protein that is present in inflammatory processes, is evaluated. However, even CRP is not a definitive indicator of disease. Rheumatic markers and autoantibodies are not present in spondyloarthritis .

Imaging methods are important . You determine whether the nerádiografickú , or radiographic axial spondyloarthritis

In the case of ankylosing spondylitis, inflammatory and structural changes of SI joints and spine are present on X-rays .

MRI is a highly detailed method. Magnetic resonance imaging can reveal the early stages of the disease, even before structural changes occur.

However, even an MRI finding is not always positively present in the disease.

Therefore, a comprehensive assessment of the difficulties encountered is important. Various classifications for the evaluation of AxSpA were created. 

The table shows the form of the disease in relation to the finding

Non-radiographic stage of
Radiographic stage

Ankylosing spondylitis
Back pain Back pain
MRI sacroiliitis
(may not be detected) 
X-ray finding of sacroileitis
   course> over the years ... bone destruction and the
presence of syndesophytes = bone protrusions
ossification of tendon attachments - transformation into bone tissue
stiffness and loss of spinal motility

Modified New York Classification for the Diagnosis of Ankylosing Spondylitis

Clinical criteria
  • pain lasting more than 3 months, improvement during exercise, but not at rest
  • limitation of lumbar spine motility
  • chest expansion limitation (inhaled)
X-ray criterion
  • 2nd stage sacroileitis bilaterally
  • unilateral stage of sacroileitis unilaterally
Evaluation of sacroiliitis on X-ray X-ray stages:
  1. suspicious changes
  2. minimal abnormalities, but without changing the width of the joint space
  3. clear abnormalities
  4. ankylosis


The course of the disease is long - chronic and creeping . There are no acute and intense pains such as in the lumbag .

Rather, it is a gradual difficulty that progresses . This means that they deteriorate over time and increase in intensity .

In the case of this type of spondyloarthritis, difficulties such as, for example, pain in the Achilles tendon, recurrent eye inflammation, irritation, redness or itching may occur in advance. Digestive problems and abdominal pain may be associated.

And back pain comes on for a long time . In addition to the crosses, the region of the hips , hip joints or buttocks is also painful

At the same time, the disease starts from a young age and back pain is present before the age of 45 .

The symptoms in this case are exacerbated by inactivity , the intensity rises at night and  wakes the person from sleep . In the morning , stiffness of the spine and joints is present . It helps to move and warm up. General fatigue also occurs during the course of the disease .

In the case of long-term pain, the disease reduces the quality of life and its more serious forms are disabled.

How it is treated: Axial spondyloarthritis

Axial spondylarthritis and treatment: pharmaceuticals, rehabilitation and physical

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