Genes involved in inflammation may hold clue
to Progressive Eye Disease
Newswise — Variations in genes that control the production of
chemicals involved in inflammation may hold
the clue to age related macular
degeneration, or AMD, suggests research
published ahead of print in the British
Journal of Ophthalmology.
AMD affects the centre of the retina (macula) at the back of
the eye, which is used for fine central
vision tasks, such as reading and driving.
It is progressive and most common in the elderly, among whom
it is a major cause of untreatable blindness
in developed countries.
The UK researchers from the University of Southampton looked
for evidence of four variations in genes
controlling the production and suppression
of cytokines - powerful chemicals involved
in inflammatory processes in the body.
They took DNA samples from 478 people with AMD and 555 people
with no signs of the disease. All of them
were aged over 55.
One of the genetic variants (251A/T), which is associated
with a gene that boosts the production of
the cytokine interleukin 8, or IL-8 for
short, was significantly more common among
the patients with AMD. This held true even
after taking account of age, sex, weight,
and smoking - known risk factors for AMD.
The IL-8 251A/T genetic variation has been previously linked
to several inflammatory diseases and cancer.
If repeated in larger studies, the authors suggest that their
findings might lead to the possibility of
genetic screening for AMD and the
development of biological agents to control
it.
In an accompanying editorial, US eye specialists from the
National Institutes of Health and the
University of Michigan, sound a note of
caution, reiterating that further studies
will be needed before a direct cause and
effect can be established.
Nevertheless, the explanation is plausible, they say. The
development of AMD has been linked to an
interplay between genetic and environmental
factors.
Natural changes as a result of ageing and the accumulation of
oxidative stress seem to be the initial
triggers for the disease, which worsens as a
result of immune system activity, they
suggest.
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