Diagnostic
Tests For Ankylosing Spondylitis Blood tests show a moderate elevation
of the ESR (sedimentation rate), the C-reactive protein and serum immunoglobulin
levels. Tests for RF or ANA titers are negative. As stated before, the HLA-B27 test is often positive.
However, this test is more reliable when it is negative as in this case it then
helps to exclude ankylosing spondylitis. X-rays of the sacroiliac joints show
very specific changes. These changes characteristic for ankylosing spondylitis
occur even in the earlier disease process and are made more reliable by employing
CT scans or MRI scans where more detail can be seen. Typical X-rays of the lumbar
spine occur later in the disease and the "bamboo spine" happens only
in a few advanced cases of ankylosing spondylitis after about 10 years of the
disease (Ref. 2, p. 446). Psoriatic arthritis
Psoriatic arthritis and the other spondyloarthropathies have other signs
that go along with the disease. For instance, with psoriatic arthritis signs such
as psoriasis plaques on the skin and pitting of nails that are typical for psoriasis
will often also be present at the same time. With the bowel diseases of Crohns
disease and ulcerative colitis
the other bowel signs are present that have been described under these links. Reiter's
syndrome
This
is a multifaceted disease where arthritis develops after a genitourinary or gastrointestinal
infection. The typical constellation of symptoms is a symptom constellation of
urethritis (inflammation of the urethra) or cervicitis (inflammation of the cervical
canal), conjunctivitis, mucous membrane and skin lesions as well as arthritis.
In the past when it was difficult to detect Chlamydia strains, it was thought
that Reiter's syndrome would be non infectious. However, now the thinking on this
has changed.What is known is that patients who develop Reiter's syndrome
are genetically found to have a high incidence of 70% to 95% of the HLA-B27 tissue
antigen. This may make them more susceptible to the strains of bacteria from sexually
transmitted diseases or gastrointestinal infections that are found in these patients
with more sensitive culture methods. Two major groups of patients have been identified
among the Reiter's syndrome patients. One group are mostly men in the 20 to 40
age group who develop the symptoms following genital infections with Chlamydia
trachomatis. Another group where men and women are equally affected is the dysenteric
form. This occurs after diarrhea from bacterial enteric infections, likely because
of a weakened immune system in association with the HLA-B27 tissue antigen (Ref.
2). Common bacteria associated with the dysenteric form are Shigella, Yersinia,
Salmonella, Campylobacter and Chlamydia. Reactive arthritis This is the
name used to describe that certain infectious diseases develop a concomitant arthritis,
but no bacteria can be found in the affected joint. It seems to be like a sympathetic
reaction, likely due to immune complexes that react with the affected joints.
There is an overlap with the dysenteric form of Reiter's syndrome. Other serious
infections that are associated with reactive arthritis are meningitis, pneumonia
with Chlamydia pneumoniae, diarrhea with enterotoxigenic strains of E. coli and
AIDS infection (due to HIV virus), just to mention a few examples. Appropriate
blood tests and cultures have to be taken in these cases.
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