HAIFA, Israel and NEW YORK, N.Y., December 21, 2001 – Researchers at the Technion-Israel Institute of Technology have identified a key factor in the cause of alopecia areata, a hair loss disorder that often strikes children. Their study, to appear in the Journal of Investigative Dermatology (December 2001), suggests that future treatments could involve desensitizing the body’s immune system to the substances that provoke the attack. The researchers previously showed that in alopecia areata, white blood cells – part of the immune system – attack hair follicles, pockets of skin cells in which hair is rooted. But what induces the attack wasn’t clear. In the new findings, researchers show that proteins produced by melanocytes, or hair pigment-producing cells, trigger the assault when the body mistakes molecules within the cells for foreign substances.
"Alopecia areata can be a very challenging condition emotionally, and it currently has no cure," said Dr. Amos Gilhar, an associate professor of medicine at the Technion Faculty of Medicine, who led the study. Dr. Gilhar conducted the study at the Flieman Geriatric Rehabilitation Hospital in Haifa. Research collaborators included Dr. Richard S. Kalish, associate professor of dermatology at Stony Brook University.
Dr. Kalish suggests that injecting high doses of the substances at issue may be one of several ways of desensitizing the body to the attacks, but says it will take further research to clarify this.
Medical experts praised the findings.
"This discovery is very important. If you've identified the enemy, you might be able to develop better-targeted ammunition to get at it," said Dr. Alice Gottlieb, professor of medicine and director of the clinical research center at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School. Dr. Gottlieb is an expert on immunology and skin diseases.
Alopecia areata commonly starts with one or more small, round, smooth, bald patches on the scalp, sometimes leading to complete hair loss in recurrent and unpredictable episodes, called alopecia totalis. In extreme cases, it can lead to complete body hair loss, alopecia universalis. It often begins in childhood, which can be psychologically devastating for its young victims. The condition strikes an estimated 1.7 percent of people, including 4 million in the United States, according to the National Alopecia Areata Foundation (NAAF).
In their study, the research team grafted bits of hairless skin from the scalps of alopecia areata patients onto special mice without immune systems, which therefore do not reject the tissue. The grafted skin usually started producing hair again.
However, the researchers induced attacks leading to hair loss in the grafted tissue by injecting the mice with the human patient’s T-cells, white blood cells that are linchpins of the immune system. When injected into the mouse, the human T-cells renewed their aggression and caused hair loss in the grafted tissue – but only if the T-cells were first exposed to a mixture of protein fragments from the patient’s hair pigment cells. This indicated that the protein fragments were acting as antigens, or molecules that stimulate an immune response, according to the researchers. The fragments were bits of molecules that are part of melanosomes, the tiny sub-section of the cell that makes the pigment.
The researchers added that the attack on the immune system appears to be coordinated by two types of T-cells, called CD4+ and CD8+.
Researchers investigated the pigment cell substances because there were several hints that these cells were involved. For instance, white hairs tend to fall out less often in many patients, suggesting that hair follicles lacking in pigment-making cells might not be as vulnerable to the attack.
The study was conducted because of the limits of current treatments.
"Several treatments for alopecia areata exist, but none works well for the cases involving the most widespread hair loss," explained Dr. Vera H. Price, chairman of the board of NAAF. "We use various chemicals that modulate the immune system, but they’re not specific enough. The most powerful treatments involve steroids, which can have significant side effects." The findings could pave the way for more effective methods.
The study was supported by NAAF – which funds research on the etiology, genetics, and basic hair biology of alopecia areata – and the Japanese Society for Investigative Dermatology. More information on the disorder can be found on the NAAF web site at www.naaf.org.
The Technion-Israel Institute of Technology is Israel's leading scientific and technological center for applied research and education. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel’s high-tech companies are Technion graduates. The Technion’s 19 faculties and 30 research centers and institutes in Haifa are home to 13,000 students and 700 faculty members.
Based in New York City, the American Technion Society (ATS) is the leading American organization supporting higher education in Israel. The ATS has raised $868 million since its inception in 1940, more than half of that during the last eight years. A nationwide membership organization with more than 20,000 supporters and 17 offices around the country, the ATS is driven by the belief that the economic future of Israel is in high technology and the future of high technology in Israel is at the Technion. Technion societies are located in 24 countries around the world.
Materials provided by American Society For Technion - Israel Institute Of Technology. Note: Content may be edited for style and length.
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