This is Professor Maureen Mayes from
the Division of Rheumatology at the McGovern Medical School,
University of Texas in Houston,
Texas talking about Environmental Scleroderma: The Evidence for External Triggers.
Scleroderma or systemic sclerosis is
a chronic auto immune disease characterized by
widespread fibrosis in the skin and internal organs.
There are also a non-inflammatory small vessel vasculopathy
with Raynaud's phenomenon as a major manifestation,
frequently leading to a scheme like Digital Tip ulcers and also
associated with a sudden increase in blood pressure known as scleroderma renal crisis,
that if untreated, can result in renal failure.
In addition to these features,
there is evidence of immune activation with the presence of scleroderma
specific autoantibodies in many but not all cases.
As is true for all autoimmune diseases,
the cause is unknown.
It is assumed, however,
that the disease occurs as a result of
some environmental exposure acting on a genetically susceptible host.
The nature of this exposure is unknown but in the correct genetically susceptible host,
these agents could include any number of
bacterial or viral infections as well as occupational or other chemical exposures,
including toxins and allergens resulting in the condition we call scleroderma.
This figure that represents the data from
the first genome-wide association study in
scleroderma was presented in Nature Genetics in 2010.
And what you can see from this figure is that all of
the genes that are represented above the red line are
areas in the genome that are significantly different
in the cases compared to controls and
this represents almost 2400 cases compared to 5200 healthy controls.
So clearly, there are genetic differences in
scleroderma cases compared to those healthy controls.