Gender Differences in Autoimmunity

Women are generally healthier and have a longer lifespan than men. However, 80% of people with autoimmune diseases are usually women of childbearing age and it is among the leading causes of disability and death. New data is now being presented for possible reasons behind gender differences in the occurrence of autoimmunity. This information will be significant for the treatment and prevention of the diseases in the future.

An autoimmune disease is a condition where the immune system starts to mistakenly attack its own body and tissues the same way it would if the cells were of a foreign invader (bacteria, virus etc). The diseases included are: Hashimoto’s thyroiditis, Grave’s disease, Multiple sclerosis (MS), Myasthenia gravis, Systematic lupus erythematosus (lupus) and Rheumatoid arthritis.

It is still not exactly clear why autoimmune diseases are more prevalent in women but there are some theories. Some researchers believe the gender differences in immunity. Thanks to having a “super immunity”, they are less likely to have an infection and have a much better antibody response to foreign invaders. However, there is a belief that because women’s immune systems are more sophisticated than men’s, they have an increased risk of developing an autoimmune disease. Inflammation plays a major role in autoimmunity and women have stronger inflammatory responses when their immune systems are triggered.

Autoimmunity can also be attributabed to the genetic susceptibility. Researchers have suggested this is partly due to the higher prevalence of the X chromosome (which has many genes relating to the immune system) contrary to men’s X and Y chromosome. There is some evidence indicating defects in the X chromosome might be related to susceptibility to certain autoimmune diseases.

Furthermore, there is suggestions that women are of higher risk due to hormonal differences. Oestrogen stimulate, and androgens protect against autoimmunity. Many autoimmune disorders begin after puberty and change during pregnancy: they tend to improve and break out along with female hormonal variations. For instance: with the menstrual cycle, during pregnancy or when using oral contraceptives. There is evidence stating that years after a woman’s pregnancy, foetal cells can remain in the body which may worsen or develop a disorder.

With the goal to treat, prevent and even cure some of these diseases, researchers are trying to figure out why women are more susceptible to autoimmune diseases. With future studies of the X-chromosome, this may identify new genes and provide further information of the complex mechanisms of autoimmunity development.

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