A prior study revealed the gene responsible for hair loss. This study shed’s light on alopecia areata which is a skin ailment causing hair loss on the scalp and elsewhere in almost 5.3 million Americans. According to experts from the Columbia University Medical Center eight genes have been discovered that help in forming alopecia areata. Most of the genes are seemingly revealed in some autoimmune diseases like rheumatoid arthritis and type 1 diabetes, currently treatments target these genes.
The experts explained that since treatments targeting these genes are already available, novel treatments for alopecia areata can also be developed. The National Alopecia Areata Foundation mentioned that this disease is faced by both men and women. Yet more number of women may generally seek treatment than men as they are diagnosed more often.
“Finding the initial genes underlying alopecia areata is a big step forward, but the nature of the genes is even more exciting. There seems to be a shared mechanism among organs that express NKG2D danger signals as part of the initiating process. And 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. Finally, we have the possibility of developing drugs that specifically target the mechanism behind the disease,” said Angela M. Christiano, Ph.D., professor of dermatology and genetics and amp; development at Columbia University Medical Center, and lead author of the study.
It has been predicted that one of the newly identified genes, ULBP3 plays a vital role during the early stages of alopecia areata. This gene is believed to act as a homing beacon for cytotoxic cells. They are seemingly able to invade and destroy an organ as soon as possible. Usually absent in hair follicles, ULBP3 proteins are supposedly found in great quantity in hair follicles that are affected by alopecia areata. The investigators revealed that these cells can potentially attract cells which are supposedly marked by a killer receptor, NKG2D.
Vicki Kalabokes, president and CEO of the National Alopecia Areata Foundation remarked, “This study is very exciting as alopecia areata affects a huge number of people worldwide, and there are very few treatments for it – resulting in an enormous unmet medical need. Hair loss is life-altering – sufferers, especially children, experience social stigma. It affects their quality of life and can lead to long-term psychosocial impact.”
Other than ULBP3, two other genes are expressed in the hair follicle while the remaining five genes are claimed to be involved in the immune response. Psoriasis was previously linked with alopecia areata as they both are inflammatory diseases attacking the skin by T cells. Scientists would therefore employ psoriasis drugs during clinical trials for alopecia areata. But they were unable to report positive results. In this study investigators identified some genes present in both the diseases. But they found more genes in common with alopecia areata and rheumatoid arthritis, celiac disease, and type 1 diabetes.
This disease starts with one or more small, round patches on the scalp. As it progresses patients may suffer from total scalp hair loss known as alopecia totalis or complete body hair loss termed as alopecia universalis. The biggest hurdle faced by scientists is that this disease apparently fails to progress in uniformity. Even though some patients may report hair growth and fall out again at any time, the same need not be shared by all.
The authors explained that since each person shows different ways of progression it is very difficult to predict a correct treatment. Available treatments for the disease include steroid injections into the scalp or other affected site of hair loss, topical foams, irritant factors, and rarely, systemic steroids. In order to ascertain a treatment the authors aimed to study the link between the number of genes that people with different severities of alopecia areata carried. They mentioned that every single gene comes in two pairs.
Dr. Christiano commented, “The advantage of this large sample size is that we can be sure that this group of genes was identified with a high statistical significance and did not happen by chance. The next step is to replicate this study in future study.”
The authors noted that the ailment in people with 13 to 14 genes did not seem to progress. But those registered with 16 or more generally appeared to further progress to alopecia universalis which means total baldness. This study encompassing more than 1,000 samples from the National Alopecia Areata Registry enabled the lead author to introduce a genetic test to determine the extremity of the disease.
The study was published in the July 1, 2010 issue of Nature.