Researchers may have uncovered the genetic basis for one of the most commons causes of hair loss. Alopecia areata, a common autoimmune skin disease that results in hair loss on the scalp and elsewhere, is to blame for 5.3 million cases of hair loss in America.
Now, a team from Columbia University Medical Center has uncovered eight genes that underpin the condition, several of which are implicated in other autoimmune disease such as rheumatoid arthritis and type 1 diabetes. The discovery, reported in a paper in the July 1, 2010 issue of Nature, means new, effective hair loss treatments could soon hit the market.
“Finding the initial genes underlying alopecia areata is a big step forward, but the nature of the genes is even more exciting,” said Angela M. Christiano, Ph.D., professor of dermatology and genetics & development at Columbia University Medical Center, and lead author of the study.
One gene, ULBP3, was identified for its role in the onset of alopecia areata. ULBP3 attracts cytotoxic cells that can invade and quickly destroy an organ. Normally, ULBP3 is not present in hair follicles, but the ULBP3 proteins are abundant in hair follicles affected by alopecia areata. The proteins attract cells marked by a killer cell receptor, known as NKG2D.
“There seems to be a shared mechanism among organs that express NKG2D danger signals as part of the initiating process,” said Dr. Christiano. “Since drugs are already in development that target these pathways — because they are being tested to treat rheumatoid arthritis, type 1 diabetes and other diseases where the NKG2D receptor is involved—we may soon be able to test these drugs in clinical trials for alopecia areata.”
Prior to the Columbia team’s findings, alopecia areata, because of its inflammatory quality, was considered similar to psoriasis. But psoriasis drugs used to treat alopecia areata have proved unsuccessful. It turns out, alopecia areata may have more genetic similarities to disease like rheumatoid arthritis, celiac, and type 1 diabetes.
Understanding the genetic makeup of alopecia areata could result in not only effective treatments but also diagnostic tests to predict the severity of the disease. The Columbia researchers found that alopecia areata in people who carried 13-14 of the identified genes did not progress, while people with 16+ genes usually developed alopecia universalis, or total baldness.