What policy includes ankylosing spondylitis

Diagnosis and therapy in transition

In AS patients, in addition to spinal complaints, numerous accompanying symptoms are possible, which occur more or less frequently. This includes iritis (inflammation of the iris of the eye), which up to 40 percent of all AS patients suffer from one or more times in their life. About a third of patients suffer from arthritis of other joints, with the disease occurring primarily in the hip joints, knees and ankles. Enthesitis (inflammation of the tendon attachments) is also typical, and this can be felt by pain in the heel, for example. Involvement of the lungs, heart and kidneys is possible (9), but relatively rare (2).

Progressive course

Most patients develop AS between the ages of 15 and 40. Statistically, the mean age at the onset of symptoms is 26 years (1). Men are often more severely affected than women and seem about two to three times as likely to get the disease.

Starting from deep-seated back pain (sacroiliitis), the inflammatory process moves further and further up the spine over time. Flares with high disease activity alternate with phases of relative calm. In the end, all sections of the spine can become inflamed and involved in the bone remodeling processes (Figure 2).

Patients experience considerable pain, especially during the flare-ups. They have to cope with everyday life, exhausted and sometimes with a fever. In addition, there is an increasing inability to move. In the later stages, restricted breathing can be an additional burden. However, complete ankylosing (stiffening) is rare. A study with 51 patients showed that the majority of irreversible changes in the spine already occur in the first ten years of the disease. Three quarters of the patients with mild restrictions in the first ten years showed no further significant deterioration even after a mean observation period of 38 years (10).

Significant predictive factors for the progression of osseous stiffening are syndesmophytes, i.e. new bone formation at the edges of the vertebral body, an increased sedimentation rate, increased values ​​of the inflammatory parameter CRP (C-reactive protein) and smoking (11).

Inadequate diagnosis - especially in the early stages

Often AS patients are not correctly diagnosed until five to ten years after the onset of symptoms (2, 10, 12). There are mutliple reasons for this. On the one hand, back pain is a non-specific symptom, so that those affected usually do not see a doctor until late. And doctors often enough just don't think about AS. Above all, however, the currently established diagnostic criteria (modified New York criteria) are inadequate. So must at least

  • a clinical criterion, for example lower back pain and stiffness for more than three months, which improve with movement, restricted movement of the lumbar spine or decreased ability of the chest to expand
  • and in addition sacroiliitis (inflammation of the sacrum and iliac joints) can be clearly identified in the conventional X-ray image.

Since the actual inflammation is not visible radiologically, bony changes must have already taken place. For the diagnosis, this means that patients in the early stages are usually not recorded.

The researchers have therefore dealt intensively with early detection over the past ten years. Their results show that inflammatory back pain alone is not enough to diagnose the early form of AS (10, 8). However, inflammatory changes in the axial skeleton can be shown well with modern imaging methods such as MRI, and this years earlier than in the X-ray image. The early indicators also include diagnostic parameters such as a good response to non-steroidal anti-inflammatory drugs (NSAIDs), positive HLA-B27 antigen, a family history of SpA and diseases such as current or previous iritis.

Based on this knowledge, new classification criteria for early detection could be developed. In 2009 they were presented to the public as the new ASAS (Assessment of Spondyloarthritis International Society) criteria (13).

In addition, axial spondyloarthritis (nr-axSpA, axSpA without X-ray evidence), which cannot be detected by X-rays, is now considered an early form of AS. Together with AS, it forms the disease group of axial spondyloarthritis, the main characteristic of which is inflammatory processes in the spine. With axSpA without X-ray evidence, in contrast to AS, no bone changes can be seen in the X-ray image. It can, but does not have to lead to an AS. However, your diagnosis is important in order to be able to start therapy at an early stage.