According to the study published in
the July issue of Nature the professor of dermatology and genetics at
Columbia, Angela Christiano et al have found
a connection between the gene called ULBP3 on Chromosome 3 and the
Alopecia Areata recently. This gene is normally not found in the hair follicles
but it was observed that ULBP3 proteins were found in high concentrations in
hair follicles affected by alopecia areata. ULBP3 attracts immune cells (called
cytotoxic cells, Natural Killer or NK Cells)
receptors called NKG2D . If an infection is present in the body, cytotoxic
cells can help fight the infection or
destroy damaged cells, but if there is no infection or damage, these immune
cells end up attacking healthy tissue. These genes ULBP3 are already associated
with a number of autoimmune disorders, including type 1 Diabetes & Rhematoid Arthritis.
Two other genes were also expressed
in hair follicles, while the remaining five genes were involved in immune
system response.
The researchers discovered that the number of
alopecia-associated genes a person had correlated with the severity of the
condition. Those who carried 16 or more genes (the genes are in pairs) were
more likely to progress to alopecia universalis, or total hair loss.
In people with alopecia, immune system T cells are present in large numbers in the hair follicle. Microscopic look is like the hair follicle is being attacked by bees, which are the T cells. Among the eight genes, one in particular -- ULBP3 -- has been shown to attract toxic cells that can invade and destroy an organ. In a person without alopecia, ULBP3 is turned off. But in people with alopecia, ULBP3 proteins are plentiful in the follicle.
In people with alopecia areata, a
huge expression of the ULBP3 gene in the outermost layer of the follicle is
seen as per Christiano. ULBP3 is a
danger signal that signals to T cells to come in and attack the follicle. It's
like putting nectar on the hair follicle, and then the 'bees' come in and do
their damage.
When the follicle is attacked, the
hair falls out. If the T cells remain, which they do in alopecia areata, the
follicle goes dormant.
The mechanism of genes pathway in
Alopecia areata has opened a new vista of developing the new drug for this
disease that affects over 5 million people only in America the disease is life-altering - sufferers,
especially children, experience social stigma. It affects their quality of life
and can lead to long-term psychosocial impact.
More over ULBP3 genes might work as
a biomarker for Alopecia areata.
