Scleroderma Is More Than Skin Deep
Genetic profile reveals skin hardening as a systemic condition
MONDAY, Sept. 29, 2003 (HealthDayNews) -- Scanning thousands of genes, scientists have found scleroderma is more than just a disease of the skin.
More than 2,700 genes found not only in skin but also in other body tissues act differently in scleroderma patients than in persons free of the condition, says a report in this week's issue of the Proceedings of the National Academy of Sciences.
Medical encyclopedias describe scleroderma as a debilitating condition that causes the skin to become painfully taut and hardened, and mention that it can be fatal if other organs are affected.
But "our results suggest that it is a systemic disease," says David Botstein, who led the study while at Stanford University and now is director of the Princeton University Lewis-Sigler Institute for Integrative Genomics. "The clinical implication is that we should not be trying to treat this disease locally. We have a systemic problem."
An estimated 300,000 Americans have scleroderma, which generally develops in people in their 40s and 50s. It is more common in women than men. The lungs, kidneys, heart and blood vessels can be damaged, and that damage can sometimes be fatal.
With funding from the Scleroderma Foundation, Botstein and his colleagues took tissue samples from four scleroderma patients and four disease-free people. Using a technique that has been applied to other diseases, most notably cancer, the researchers measured patterns of expression of more than 12,000 genes.
As expected, the activity of a large number of those genes -- 2,776, to be precise -- differed in people with and without scleroderma. But the surprise was that in the scleroderma patients, gene activity in patches of skin affected by the disease was the same as in unaffected skin.
"Now we have a handle on a disease that is very tough to manage," says Dr. Kari Connolly, an associate professor of dermatology and medicine at the University of California, San Francisco, a member of the research team.
The next step will be to extend the genetic studies in a transcontinental effort that will include Michael L. Whitfield, whose new genetics laboratory is at Dartmouth Medical School.
"We will do studies in a larger number of patients with a wider range of severity," Connolly says. "We will do studies sequentially over time to see how these genes are changing to see if we can use them as a tool for early diagnosis. I will get the tissue samples together and Mike Whitfield will get the genetic arrays together."
The hope is the studies will lead to treatment of the underlying cause of the disease, Connolly says. Treatment today is aimed at relieving symptoms such as pain, swelling and tissue damage. Those treatments "are better than nothing, and they are helping patients live longer," Connolly says, but they are not aimed at the underlying cause of the symptoms.
"Somewhere in that package of 2,776 genes are the clues we need to look in a more sophisticated way at the many abnormalities that show up in this disease," Connolly says.