1. HLA B27 (human leukocyte
antigen) is not a disease. It is a gene in your body.
2.
A positive HLA
B27 test does not mean you have a disease. If you look at the whole population
the majority of people carrying this gene will not develop ankylosing
spondylitis. The usefulness of the test depends on the context that it is
ordered in. History and examination is really useful.
3.
HLA-B27 is a
normal genetic variant. HLA B27 can be positive in upto 8% of normal
population.
4.
HLA B27
positivity is associated with a variety of diseases like ankylosing spondylitis,
psoriasis, inflammatory bowel disease, reactive arthritis etc.
5.
If your HLA B27
test is positive usually there is no need to have this test again. It does not
disappear even after treatment.
6.
Around 80 to
90% of patients with ankylosing spondylitis tests positive for HLA-B27.
7.
If you look
indiscriminately at the whole population, only 10-15% of those with this
HLA-B27 gene will end up developing ankylosing spondylitis or another type of
spondyloarthritis.
8.
History
suggestive of inflammatory back pain should prompt a doctor to order the
HLA-B27 test. In this context, a positive HLA B27 test is useful in making the
diagnosis.
9. Please note a negative
HLA-B27 test does not completely rule out the diagnosis of ankylosisng
spondylitis. Around 10-20% of patients with proven ankylosing spondylitis will
test negative for HLA B27.
10. Treatment depends on the
final diagnosis and severity of the disease.
Symptoms of
inflammatory back pain –
#1. Starts
before the age of 40 years
#2. Comes on
slowly over time
#3. Worse in
the mornings and evening
#4. Stiffness
in the mornings or after period of inactivity
#5. Improves
with exercise and worse with rest
#6. Can often
cause pain in the buttocks
For more information please visit punerheumatologist.com
