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This drawing shows a comparison between a healthy hair follicle and a damaged hair follicle due to effects of Alopecia Areata and immune privilege.
Alopecia Areata; functions of white blood cells – Justine Lovely
This drawing shows a comparison between a healthy hair follicle and a damaged hair follicle due to effects of Alopecia Areata and immune privilege.
This project is about Alopecia areata (AA) which is an autoimmune disorder where the WBCs of the immune system attack hair follicles, resulting in hair loss or patchy hair. Perifollicular mast cells play a role in different immune processes such as hair growth and hair follicle immune privilege. Hair follicle immune privilege means the immune system is less likely to attack hair follicles when they are growing. The mast cells release inflammation mediates (i.e histamine) to battle possible inflammation or immune response that could occur. In AA, the immune system attacks and damages these follicles due to the increase of mast cells. It eventually breaks down the follicles defense system and promotes Cytotoxic T lymphocytes (CTL) activation. The CTLs try to attack the hair follicle since they believe they are foreign invaders and therefore heightens the inflammatory response.
Alongside the increase of mast cells and CTLs, there is a decrease in T-regulatory cells. These are a type of T lymphocyte that ensures the immune system doesn’t “overreact” to foreign substances if they aren’t harmful. They maintain homeostasis as well as prevent autoimmune disorders. They suppress the immune response when the body wants to attack its own body, cells, and tissues. When cell count is low, it makes it easier for mast cells and CTLs to attack hair follicles as the homeostatic balance is disrupted. This leads to the death of hair follicles and therefore, hair loss.